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BIOS.S@ 7bf3856

Last change on this file since 7bf3856 was 3ae31e9, checked in by Thomas Lopatic <thomas@…>, 8 years ago
Imported original source code.
Property mode set to `100755`
File size: 108.9 KB

Rev	Line
[3ae31e9]	1	********************************************************************************
	2	* *
	3	* bios.s -- BIOS for the Buchla 700 and NASA 3D Helmet Display *
	4	* ------ -------------------------------------------------- *
	5	* *
	6	* See VM1,VM2 and VDATE for version and date *
	7	* Written by D.N. Lynx Crowe *
	8	* *
	9	* Very loosely based on ideas from: *
	10	* *
	11	* "Atari ST Internals", by Abacus Software, *
	12	* "A Hitchhiker's Guide to the BIOS", by Atari, *
	13	* "DOS Technical Reference", by IBM, *
	14	* "DOS/360", by IBM,
	15	* "CP/M" , by Digital Research, and, of course, *
	16	* "Unix (tm)", by AT&T, et al. *
	17	* *
	18	* After all, Why re-invent the wheel? *
	19	* *
	20	* Some of the functions are the same as Ataris, but quite a few are different, *
	21	* and our I/O configuration is much different, so BEWARE! Make no *
	22	* assumptions, and read the documentation and comments very carefully. *
	23	* *
	24	* Especially watch out for the extended BIOS functions. Most of them *
	25	* are nothing at all like the Atari / GEMDOS extended bios functions, *
	26	* and even the ones that are similar have different numbers. *
	27	********************************************************************************
	28	*
	29	.text
	30	*
	31	* Version and date
	32	* ----------------
	33	VM1 .equ 18 * First part of version number
	34	VM2 .equ 0 * Second part of version number
	35	VDATE .equ $19880620 * Version date
	36	*
	37	BUCHLA .equ 1 * Non-Zero for Buchla 700, 0 for NASA
	38	NASASIO .equ 0 * Non-zero for NASA, 0 for Buchla addr.
	39	*
	40	FL_SKR .equ $00 * Seek rate (WD1772, 6Ms/step)
	41	*************************************************************************
	42	*
	43	.page
	44	*
	45	.xref start_ * Where ROMP starts
	46	.xref _errno * Start of ROMP bss space
	47	*
	48	.xdef basepage * Pseudo base page for romp
	49	.xdef _rsflag * Register save area overflow flag
	50	*
	51	.ifne BUCHLA
	52	*
	53	.xdef _hdvini * Disk init
	54	*
	55	.endc
	56	*
	57	.xdef _wzcrsh * ROMP crash flag
	58	.xdef _crshvc * Crash vector
	59	.xdef _crshsr * Crash SR
	60	.xdef _crshpc * Crash PC
	61	.xdef _crshsp * Crash SP
	62	.xdef _crshus * Crash USP
	63	.xdef _crshrg * Crash SP registers
	64	.xdef _crshst * Crash top of stack
	65	*
	66	.page
	67	*
	68	.ifne BUCHLA
	69	*
	70	.xdef _hz_1k
	71	.xdef _hz_200
	72	.xdef frclock
	73	.xdef t1count
	74	.xdef t2count
	75	.xdef t3count
	76	*
	77	.xdef nflops
	78	.xdef disknum
	79	.xdef booted
	80	.xdef seekrate
	81	.xdef flock
	82	.xdef fverify
	83	*
	84	.xdef retrycnt
	85	.xdef wpstatus
	86	.xdef wplatch
	87	.xdef bootdev
	88	*
	89	.xdef cdev
	90	.xdef ctrack
	91	.xdef csect
	92	.xdef cside
	93	.xdef ccount
	94	*
	95	.xdef cdma
	96	.xdef edma
	97	.xdef tmpdma
	98	.xdef rseed
	99	*
	100	.xdef savptr
	101	*
	102	.xdef flpsrsv
	103	.xdef flpregs
	104	*
	105	.xdef dsb0
	106	.xdef dsb1
	107	*
	108	.xdef dskmode
	109	.xdef dskerrs
	110	.xdef drvbpbs
	111	*
	112	.endc
	113	*
	114	.xdef biostop
	115	*
	116	.page
	117	*
	118	* Some critical equates:
	119	* ----------------------
	120	* Interrupt masks
	121	* ---------------
	122	IPL3 .equ $0300 * IPL 3 value for sr
	123	IPL4 .equ $0400 * IPL 4 value for sr
	124	IPL7 .equ $0700 * IPL 7 value for sr (4 for debug)
	125	*
	126	.ifne BUCHLA
	127	*
	128	INITIPL .equ IPL3+$2000 * Initial Internal Priority Level
	129	*
	130	.endc
	131	*
	132	.ifeq BUCHLA
	133	*
	134	INITIPL .equ IPL4+$2000 * Initial Internal Priority Level
	135	*
	136	.endc
	137	*
	138	* Memory allocation
	139	* -----------------
	140	.ifeq BUCHLA
	141	*
	142	TPA .equ $008000 * Put TPA 32K up from the bottom
	143	*
	144	.endc
	145	*
	146	.ifne BUCHLA
	147	*
	148	TPA .equ $010000 * Put TPA 64K up from the bottom
	149	*
	150	.endc
	151	*
	152	SSTACK .equ TPA * Put system stack just below TPA
	153	*
	154	p_bbase .equ $0018 * Basepage offset to bss base
	155	p_blen .equ $001C * Basepage offset to bss length
	156	*
	157	* It's magic ...
	158	* --------------
	159	FMAGIC .equ $87654321 * Magic for formatting
	160	RETRYIT .equ $10000 * Magic for re-try from criter
	161	RSMAGIC .equ $78563412 * Magic for register save area OK
	162	*
	163	* Miscellaneous constants
	164	* -----------------------
	165	FCMAX .equ $00FFFFFF * Maximum frame counter value (24 bits)
	166	*
	167	.page
	168	*
	169	* CFR0 Baud Rates:
	170	* ----------------
	171	BR_300 .equ $04
	172	BR_600 .equ $05
	173	BR_1200 .equ $06
	174	BR_1800 .equ $07
	175	BR_2400 .equ $08
	176	BR_3600 .equ $09
	177	BR_4800 .equ $0A
	178	BR_7200 .equ $0B
	179	BR_9600 .equ $0C
	180	BR_19K2 .equ $0D
	181	BR_EXT .equ $0F
	182	*
	183	* CFR0 Stop bits (includes TBR select bit):
	184	* -----------------------------------------
	185	NSB_1 .equ $40
	186	NSB_2 .equ $60
	187	*
	188	* CFR1 Number of Data Bits (includes MSB):
	189	* ----------------------------------------
	190	NDB_5 .equ $80
	191	NDB_6 .equ $A0
	192	NDB_7 .equ $C0
	193	NDB_8 .equ $E0
	194	*
	195	* CFR1 Parity Selection:
	196	* ----------------------
	197	P_ODD .equ $04
	198	P_EVEN .equ $0C
	199	P_MARK .equ $14
	200	P_SPACE .equ $1C
	201	*
	202	P_NONE .equ $00
	203	*
	204	* Line Discipline:
	205	* ----------------
	206	L_NUL .equ $00 * No protocol
	207	L_XON .equ $01 * XON/XOFF
	208	L_RTS .equ $02 * RTS/CTS
	209	*
	210	.page
	211	*
	212	* I/O Buffer Sizes:
	213	* -----------------
	214	SR1IBS .equ 256
	215	SR1OBS .equ 256
	216	SR2IBS .equ 256
	217	SR2OBS .equ 256
	218	*
	219	.ifne BUCHLA
	220	*
	221	MC1IBS .equ 512
	222	MC1OBS .equ 256
	223	MC2IBS .equ 512
	224	MC2OBS .equ 256
	225	*
	226	.endc
	227	*
	228	* Line Disciplines:
	229	* -----------------
	230	SR1DISC .equ L_XON
	231	SR2DISC .equ L_XON
	232	*
	233	.ifne BUCHLA
	234	*
	235	MC1DISC .equ L_NUL
	236	MC2DISC .equ L_NUL
	237	*
	238	.endc
	239	*
	240	* CFR Setings:
	241	* ------------
	242	SR1CFR0 .equ BR_9600+NSB_1
	243	SR1CFR1 .equ NDB_8+P_NONE
	244	SR2CFR0 .equ BR_9600+NSB_1
	245	SR2CFR1 .equ NDB_8+P_NONE
	246	*
	247	.ifne BUCHLA
	248	*
	249	MC1CFR0 .equ BR_EXT+NSB_1
	250	MC1CFR1 .equ NDB_8+P_NONE
	251	MC2CFR0 .equ BR_EXT+NSB_1
	252	MC2CFR1 .equ NDB_8+P_NONE
	253	*
	254	.endc
	255	*
	256	.page
	257	*
	258	* I/O Addresses:
	259	* --------------
	260	VSDDINIT .equ $200400 * VSDD initial register base address
	261	VSDDDATA .equ $200000 * VSDD data segment base address
	262	*
	263	.ifeq BUCHLA
	264	*
	265	.ifeq NASASIO
	266	*
	267	SR1ACIA .equ $3A8001 * Serial-1 ACIA base address (BUCHLA)
	268	SR2ACIA .equ $3A8009 * Serial-2 ACIA base address
	269	*
	270	.endc
	271	*
	272	.ifne NASASIO
	273	*
	274	SR1ACIA .equ $398001 * Serial-1 ACIA base address (NASA)
	275	SR2ACIA .equ $398009 * Serial-2 ACIA base address
	276	*
	277	.endc
	278	*
	279	.endc
	280	*
	281	.ifne BUCHLA
	282	*
	283	FPUBASE .equ $180000 * FPU base address
	284	TIMER .equ $3A0001 * Timer base address
	285	LCD .equ $3A4001 * LCD driver base address
	286	SR1ACIA .equ $3A8001 * Serial-1 ACIA base address (BUCHLA)
	287	SR2ACIA .equ $3A8009 * Serial-2 ACIA base address
	288	MC1ACIA .equ $3AC001 * MIDI-1 ACIA base address
	289	MC2ACIA .equ $3AC009 * MIDI-2 ACIA base address
	290	FLOPPY .equ $3B0001 * Floppy controller base address
	291	PSG .equ $3B4001 * Sound chip base address
	292	LEDS .equ $3B8001 * LED driver base address
	293	ANALOG .equ $3BC001 * Analog processor base address
	294	*
	295	* FPU address offsets and misc. values
	296	*
	297	FPU_CTL .equ $4000 * FPU control
	298	*
	299	FPU_IN .equ $4000 * FPU input address
	300	FPU_CLR .equ $6000 * FPU interrupt reset address
	301	*
	302	FPU_RST .equ $0015 * FPU reset value
	303	*
	304	* PSG address offsets
	305	*
	306	PSG_RD .equ PSG * Read PSG data
	307	PSG_WL .equ PSG * Write PSG address latch
	308	PSG_WD .equ PSG+2 * Write PSG data
	309	*
	310	.endc
	311	*
	312	* VSDD data structure offsets
	313	*
	314	VSDD_REG .equ VSDDDATA * Registers
	315	VSDD_AT .equ VSDDDATA+$0100 * Access Table
	316	*
	317	.ifne BUCHLA
	318	*
	319	* Timer registers
	320	*
	321	TIME_CRX .equ TIMER * Control register 1 or 3
	322	TIME_CR2 .equ TIMER+2 * Control register 2
	323	TIME_T1H .equ TIMER+4 * Timer 1 high byte
	324	TIME_T1L .equ TIMER+6 * Timer 1 low byte
	325	TIME_T2H .equ TIMER+8 * Tiemr 2 high byte
	326	TIME_T2L .equ TIMER+10 * Timer 2 low byte
	327	TIME_T3H .equ TIMER+12 * Timer 3 high byte
	328	TIME_T3L .equ TIMER+14 * Timer 3 low byte
	329	*
	330	.endc
	331	*
	332	* ACIA Register offsets:
	333	* ----------------------
	334	ACIA_IER .equ 0 * ACIA IER offset
	335	ACIA_ISR .equ 0 * ACIA ISR offset
	336	ACIA_CSR .equ 2 * ACIA CSR offset
	337	ACIA_CFR .equ 2 * ACIA CFR offset
	338	ACIA_TBR .equ 4 * ACIA TBR offset
	339	ACIA_TDR .equ 6 * ACIA TDR offset
	340	ACIA_RDR .equ 6 * ACIA RDR offset
	341	*
	342	.page
	343	*
	344	.ifne BUCHLA
	345	*
	346	* Floppy register offsets:
	347	* ------------------------
	348	DSKCMD .equ 0 * Command / status
	349	DSKTRK .equ 2 * Track
	350	DSKSEC .equ 4 * Sector
	351	DSKDAT .equ 6 * Data
	352	*
	353	* Miscellaneous equates:
	354	* ----------------------
	355	FL_NC .equ $02 * Non-compensated R/W/F bit
	356	*
	357	APISIZE .equ 256 * Analog processor buffer size
	358	*
	359	* Floppy commands:
	360	* ----------------
	361	FL_RS .equ $80 * Read sector
	362	FL_RM .equ $90 * Read multiple
	363	FL_WS .equ $A0 * Write sector
	364	FL_WT .equ $F0 * Write track (format)
	365	FL_FR .equ $D0 * Force reset
	366	FL_SK .equ $10 * Seek
	367	FL_SV .equ $14 * Seek w/verify
	368	*
	369	.endc
	370	*
	371	.page
	372	*
	373	* iorec structure definitions:
	374	* ----------------------------
	375	IORECLN .equ 40 * Length of an iorec structure
	376	*
	377	ibuf .equ 0 * Input buffer base address
	378	ibufsize .equ 4 * Input buffer size (bytes)
	379	ibufhd .equ 6 * Input buffer head index
	380	ibuftl .equ 8 * Input buffer tail index
	381	ibuflow .equ 10 * Input buffer low water mark
	382	ibufhi .equ 12 * Input buffer high water mark
	383	obuf .equ 14 * Output buffer base address
	384	obufsize .equ 18 * Output buffer size (bytes)
	385	obufhd .equ 20 * Output buffer head index
	386	obuftl .equ 22 * Output buffer tail index
	387	obuflow .equ 24 * Output buffer low water mark
	388	obufhi .equ 26 * Output buffer high water mark
	389	cfr0 .equ 28 * ACIA CFR, MS bit = 0
	390	cfr1 .equ 29 * ACIA CFR, MS bit = 1
	391	flagxon .equ 30 * XON flag (non-zero = XOFF sent)
	392	flagxoff .equ 31 * XOFF flag (non-zero = active)
	393	linedisc .equ 32 * Line discipline flags
	394	erbyte .equ 33 * Last error byte
	395	isr .equ 34 * ACIA ISR on interrupt
	396	csr .equ 35 * ACIA CSR on interrupt
	397	errct .equ 36 * Error count (FRM/OVR/BRK)
	398	ibfct .equ 38 * Input buffer full count
	399	*
	400	.page
	401	*
	402	* Error codes:
	403	* ------------
	404	ERR01 .equ -1 * All purpose error
	405	ERR02 .equ -2 * Drive not ready
	406	ERR03 .equ -3 * Unknown command
	407	ERR04 .equ -4 * CRC Error
	408	ERR05 .equ -5 * Invalid request
	409	ERR06 .equ -6 * Seek error
	410	ERR07 .equ -7 * Unknown media
	411	ERR08 .equ -8 * Sector not found
	412	ERR09 .equ -9 * End of media (out of paper)
	413	ERR10 .equ -10 * Write fault
	414	ERR11 .equ -11 * Read fault
	415	ERR12 .equ -12 * General mishap
	416	ERR13 .equ -13 * Write protected
	417	ERR14 .equ -14 * Media changed
	418	ERR15 .equ -15 * Unknown device
	419	ERR16 .equ -16 * Bad sectors
	420	ERR17 .equ -17 * Insert disk
	421	*
	422	.page
	423	*
	424	* In the Beginning...
	425	* -------------------
	426	*
	427	* Low PROM -- Contains the initial sp (unused), and the initial pc,
	428	* as well as some version and creation date stuff and a copyright message,
	429	* just to be thorough about it.
	430	*
	431	begin: bra.s biosinit * Jump to bios init
	432	*
	433	vermsg: dc.b VM1,VM2 * Version number
	434	*
	435	dc.l biosinit * Reset address (bios init)
	436	*
	437	created: dc.l VDATE * Creation date
	438	*
	439	copyrite: dc.b '{Copyright 1988 by ' * Copyright message
	440	dc.b 'D.N. Lynx Crowe}',0
	441	*
	442	dc.l 0 * Some padding
	443	*
	444	.page
	445	.even
	446	*
	447	* biosinit -- Setup the defaults for the BIOS
	448	* -------- -------------------------------
	449	biosinit: move.w #$2700,sr * Set sup mode, no interrupts
	450	move.l #SSTACK,a7 * Setup supervisor stack pointer
	451	*
	452	lea badtrap,a1 * Set default trap vector
	453	adda.l #$02000000,a1 * ... with trap # in 31..24
	454	lea 8,a0 * ... for traps 2..255
	455	move.l #253,d1
	456	*
	457	binit1: move.l a1,(a0)+ * Store trap vector
	458	adda.l #$01000000,a1 * Increment trap #
	459	dbf d1,binit1 * Loop until done
	460	*
	461	lea biosram,a0 * Clear BIOS ram ...
	462	lea SSTACK-2,a1 * ... from biosram to SSTACK-1
	463	*
	464	binit2: move.w #0,(a0)+ * Zero a word
	465	cmpa.l a0,a1 * Last one ?
	466	bne binit2 * Loop if not
	467	*
	468	move.l #rsarea,savptr * Setup pointer to register area
	469	move.l #RSMAGIC,_rsflag * Set magic in _rsflag
	470	*
	471	move.l #nullrts,timevec * Set timer interrupt vector
	472	move.l #nullrts,critvec * Set critical error vector
	473	move.l #nullrts,termvec * Set process terminate vector
	474	move.l #nullrts,resvec3 * Set software vector 3
	475	move.l #nullrts,resvec4 * Set software vector 4
	476	move.l #nullrts,resvec5 * Set software vector 5
	477	move.l #nullrts,resvec6 * Set software vector 6
	478	move.l #nullrts,resvec7 * Set software vector 7
	479	*
	480	move.l #hardhlt,$0008 * Set bus error vector
	481	move.l #nullrte,$0014 * Set divide error vector
	482	move.l #nullrte,$0018 * Set CHK vector
	483	move.l #nullrte,$001C * Set TRAPV vector
	484	move.l #nullrte,$0024 * Set trace vector
	485	*
	486	move.l #nullrte,$0030 * Set reserved vector 12
	487	move.l #nullrte,$0034 * Set reserved vector 13
	488	move.l #nullrte,$0038 * Set reserved vector 14
	489	*
	490	move.l #nullrte,$003C * Set uninitialized int. vector
	491	*
	492	move.l #nullrte,$0040 * Set reserved vector 16
	493	move.l #nullrte,$0044 * Set reserved vector 17
	494	move.l #nullrte,$0048 * Set reserved vector 18
	495	move.l #nullrte,$004C * Set reserved vector 19
	496	move.l #nullrte,$0050 * Set reserved vector 20
	497	move.l #nullrte,$0054 * Set reserved vector 21
	498	move.l #nullrte,$0058 * Set reserved vector 22
	499	move.l #nullrte,$005C * Set reserved vector 23
	500	*
	501	move.l #nullrte,$0060 * Set spurious int. vector
	502	*
	503	move.l #serintr,$0074 * Set ACIA interrupt vector
	504	move.l #nullrte,$0078 * Set level 6 vector
	505	move.l #nullrte,$007C * Set level 7 vector
	506	*
	507	move.l #trap13,$00B4 * Set trap13 vector
	508	move.l #trap14,$00B8 * Set trap14 vector
	509	*
	510	.page
	511	*
	512	.ifne BUCHLA
	513	*
	514	move.l #nullfpu,$0068 * Set FPU interrupt vector
	515	move.l #api_int,$006C * Set analog trap vector
	516	move.l #timeint,$0070 * Set timer trap vector
	517	*
	518	move.l #_hdvini,hdv_init * Set disk init vector
	519	move.l #getbpb,hdv_bpb * Set get BPB vector
	520	move.l #rwabs,hdv_rw * Set disk I/O vector
	521	move.l #bootload,hdv_boot * Setup boot load vector
	522	move.l #mediach,hdv_mchg * Setup media change vector
	523	*
	524	move.w #$FFFF,fverify * Set read after write flag
	525	move.w #FL_SKR,seekrate * Set default seek rate
	526	move.w #$FFFF,booted * Say we're not booted yet
	527	move.l #buffer,dskbufp * Setup default disk buffer
	528	*
	529	.page
	530	*
	531	move.b #7,PSG_WL * Select PSG R7
	532	move.b #$80,PSG_WD * Write $80 (port B = output)
	533	move.b #15,PSG_WL * Select PSG R15
	534	move.b #$00,PSG_WD * Write $00 (sync enable)
	535	*
	536	move.b #$00,TIME_T1H * Setup timer 1 (PLL)
	537	move.b #$1F,TIME_T1L * ... for divide by 64
	538	move.b #$0C,TIME_T2H * Setup timer 2 (FC)
	539	move.b #$7F,TIME_T2L * ... for divide by 3200
	540	move.b #$03,TIME_T3H * Setup timer 3 (RTC)
	541	move.b #$20,TIME_T3L * ... for 1Ms interval
	542	move.b #$42,TIME_CRX * Setup CR3
	543	move.b #$41,TIME_CR2 * Setup CR2
	544	move.b #$81,TIME_CRX * Setup CR1
	545	move.b #$80,TIME_CRX * Start the timers
	546	*
	547	.endc
	548	*
	549	lea sr1iorec,a0 * Serial-1 iorec address to a0
	550	lea SR1ACIA,a1 * Serial-1 ACIA address to a1
	551	lea sr1dflt,a2 * Serial-1 dflt table addr to a2
	552	bsr.w aciainit * Go initialize the port
	553	*
	554	lea sr2iorec,a0 * Serial-2 iorec address to a0
	555	lea SR2ACIA,a1 * Serial-2 ACIA address to a1
	556	lea sr2dflt,a2 * Serial-2 dflt table addr to a2
	557	bsr.w aciainit * Go initialize the port
	558	*
	559	.ifne BUCHLA
	560	*
	561	lea mc1iorec,a0 * MIDI-1 iorec address to a0
	562	lea MC1ACIA,a1 * MIDI-1 ACIA address to a1
	563	lea mc1dflt,a2 * MIDI-1 dflt table addr to a2
	564	bsr.w aciainit * Go initialize the port
	565	*
	566	lea mc2iorec,a0 * MIDI-2 iorec address to a0
	567	lea MC2ACIA,a1 * MIDI-2 ACIA address to a1
	568	lea mc2dflt,a2 * MIDI-2 dflt table addr to a2
	569	bsr.w aciainit * Go initialize the port
	570	*
	571	.page
	572	*
	573	lea VSDDINIT,a1 * Setup to load VSDD regs
	574	lea vsddtab,a0 * ... from vsddtab
	575	move.w #15,d0 * ... all 16 registers
	576	*
	577	vsddinit: move.w (a0)+,(a1)+ * Load the VSDD registers
	578	btst.l #0,d0
	579	btst.l #0,d0
	580	btst.l #0,d0
	581	dbf d0,vsddinit
	582	*
	583	move.w vsddit02,VSDDINIT * Enable the video
	584	*
	585	move.l #api_fum,api_fi * Clear analog processor fifo
	586	move.l #api_fum,api_fo * ...
	587	*
	588	move.w #23,d0 * Setup to clear key LEDs
	589	move.b #$80,d1 * ...
	590	*
	591	ledclear: move.b d1,LEDS * Clear a LED
	592	addq.b #1,d1 * Increment LED number
	593	dbra d0,ledclear * Loop until all are done
	594	*
	595	move.w #7,d0 * Setup to clear pot LEDs
	596	move.b #$18,d1 * ...
	597	*
	598	ledclr2: move.b d1,LEDS * Clear a LED
	599	addq.b #1,d1 * Increment LED number
	600	dbra d0,ledclr2 * Loop until all are done
	601	*
	602	clr.w fc_sw * Stop the frame clock
	603	clr.l fc_val * ... and reset it
	604	*
	605	.page
	606	*
	607	lea FPUBASE+FPU_CTL,a0 * Point at FPU master level
	608	move.w #$0000,$08(a0) * Set CV1 to 0
	609	addq.w #1,d0 * Delay
	610	addq.w #1,d0 * ...
	611	move.w #$0000,$0A(a0) * Set SF1 to 0
	612	addq.w #1,d0 * Delay
	613	addq.w #1,d0 * ...
	614	move.w #$0000,$0C(a0) * Set CV2 to 0
	615	addq.w #1,d0 * Delay
	616	addq.w #1,d0 * ...
	617	move.w #$0000,$0E(a0) * Set SF2 to 0
	618	addq.w #1,d0 * Delay
	619	addq.w #1,d0 * ...
	620	move.w #$0000,$10(a0) * Set CV3 to 0
	621	addq.w #1,d0 * Delay
	622	addq.w #1,d0 * ...
	623	move.w #$0000,$12(a0) * Set SF3 to 0
	624	addq.w #1,d0 * Delay
	625	addq.w #1,d0 * ...
	626	move.w #$8300,$02(a0) * Set new value '10' to -10.00
	627	addq.w #1,d0 * Delay
	628	addq.w #1,d0 * ...
	629	move.w #$8300,$1C(a0) * Set new value '01' to -10.00
	630	addq.w #1,d0 * Delay
	631	addq.w #1,d0 * ...
	632	move.w #$0001,$16(a0) * Set exponent for shortest time
	633	addq.w #1,d0 * Delay
	634	addq.w #1,d0 * ...
	635	move.w #$FFF0,$14(a0) * Set mantissa for shortest time
	636	addq.w #1,d0 * Delay
	637	addq.w #1,d0 * ...
	638	move.w #$0005,$00(a0) * Send control word to FPU
	639	*
	640	.endc
	641	*
	642	.page
	643	*
	644	move.w #INITIPL,sr * Enable interrupts
	645	lea basepage,a1 * Pass start_ a pseudo base page
	646	move.l #_errno,p_bbase(a1) * ...
	647	clr.l p_blen(a1) * ...
	648	move.l a1,-(a7) * ...
	649	jsr start_ * Go start ROMP (we assume ...)
	650	*
	651	jmp biosinit * Just in case we return ...
	652	*
	653	.page
	654	*
	655	.ifne BUCHLA
	656	*
	657	* nullfpu -- Null FPU trap handler
	658	* ------- ---------------------
	659	nullfpu: movem.l d0-d0/a0-a0,-(a7) * Save registers
	660	movea.l #FPUBASE,a0 * Setup FPU base address in a0
	661	move.w FPU_IN(a0),d0 * Read FPU interrupt port
	662	andi.l #$000000FF,d0 * Mask for voice & parameter
	663	lsl.l #5,d0 * Shift for word offset
	664	addi.l #FPU_CTL,d0 * Add FPU control offset
	665	move.w #FPU_RST,0(a0,d0.L) * Reset the function
	666	clr.w FPU_CLR(a0) * Clear the interrupt
	667	movem.l (a7)+,d0-d0/a0-a0 * Restore registers
	668	rte * Return to interrupted code
	669	*
	670	.endc
	671	*
	672	.page
	673	*
	674	* hardhlt -- Bus error trap handler
	675	* ------- ----------------------
	676	hardhlt: stop #$2700 * stop dead -- system is AFU
	677	bra hardhlt * ...
	678	*
	679	* badtrap -- Bad trap handler
	680	* ------- ----------------
	681	badtrap: move.w (a7)+,_crshsr * Get crash SR
	682	move.l (a7)+,_crshpc * Get crash PC
	683	move.l a7,_crshsp * Get crash SP
	684	bsr badtr1 * Get TRAP PC with vector number
	685	nop
	686	*
	687	badtr1: move.l (a7)+,_crshvc * Save for analysis of vector #
	688	movem.l d0-d7/a0-a7,_crshrg * Save crash registers
	689	move.l usp,a0 * Preserve crash USP
	690	move.l a0,_crshus * ...
	691	move.l a7,d0 * Get SP
	692	andi.l #$FFFFFFFE,d0 * ... make sure it's even
	693	movea.l d0,a1 * ...
	694	move.w #15,d0 * Save top 16 words
	695	lea _crshst,a0 * ... of crash stack in _crshst
	696	*
	697	badtr2: move.w (a1)+,(a0)+ * Save a stack value
	698	dbf d0,badtr2 * Loop until all are saved
	699	*
	700	clr.l d0 * Get TRAP number
	701	move.b _crshvc,d0 * ... as LS byte of d0
	702	move.l _crshpc,a0 * Save crash PC in a0
	703	move.w #$FFFF,_wzcrsh * Indicate we crashed
	704	move.l #rsarea,savptr * Restore system save pointer
	705	move.l #SSTACK,a7 * Reset the stack pointer
	706	move.l #RSMAGIC,_rsflag * ... and the stack sentinel
	707	trap #15 * TRAP to ROMP
	708	*
	709	jmp biosinit * Recover with a cold start
	710	*
	711	.page
	712	*
	713	.ifne BUCHLA
	714	*
	715	* timeint -- Timer interrupt handler
	716	* ------- -----------------------
	717	timeint: movem.l d0-d7/a0-a6,-(a7) * Save registers
	718	move.b TIME_CR2,d0 * Get timer interrupt status
	719	btst.l #2,d0 * Check timer 3 status
	720	beq tmi02 * Jump if not active
	721	*
	722	move.b TIME_T3H,d1 * Read timer 1 count
	723	lsl.l #8,d1 * ...
	724	move.b TIME_T3L,d1 * ...
	725	move.w d1,t3count * ... and save it
	726	*
	727	addq.l #1,_hz_1k * Update 1ms clock (1 KHz)
	728	*
	729	move.w tdiv1,d1 * Update divider
	730	addq.w #1,d1 * ...
	731	move.w d1,tdiv1 * ...
	732	*
	733	cmpi.w #5,d1 * Do we need to update _hz_200 ?
	734	blt tmi02 * Jump if not
	735	*
	736	addq.l #1,_hz_200 * Update 5ms clock (200 Hz)
	737	*
	738	move.w tdiv2,d1 * Update divider
	739	addq.w #1,d1 * ...
	740	move.w d1,tdiv2 * ...
	741	*
	742	cmpi.w #4,d1 * Do we need to update frclock ?
	743	blt tmi01 * Jump if not
	744	*
	745	addq.l #1,frclock * Update 20 Ms clock (50 Hz)
	746	tst.w flock * See if floppy is active
	747	bne tmi00 * Don't call flopvbl if so
	748	*
	749	bsr flopvbl * Check on the floppy
	750	*
	751	tmi00: move.w #0,tdiv2 * Reset tdiv2
	752	*
	753	tmi01: move.w #0,tdiv1 * Reset tdiv1
	754	*
	755	.page
	756	*
	757	tmi02: btst.l #0,d0 * Check timer 1 int
	758	beq tmi03 * Jump if not set
	759	*
	760	move.b TIME_T1H,d1 * Read timer 1 to clear int.
	761	lsl.l #8,d1 * ...
	762	move.b TIME_T1L,d1 * ...
	763	move.w d1,t1count * ... and save the count
	764	*
	765	tmi03: btst.l #1,d0 * Check for timer 2 int.
	766	beq tmi04 * Jump if not set
	767	*
	768	move.b TIME_T2H,d1 * Read timer 2 to clear int.
	769	lsl.l #8,d1 * ...
	770	move.b TIME_T2L,d1 * ...
	771	move.w d1,t2count * ... and save the count
	772	*
	773	tst.w fc_sw * Should we update the frame ?
	774	beq tmi04 * Jump if not
	775	*
	776	bmi tmi05 * Jump if we count down
	777	*
	778	move.l fc_val,d0 * Get the frame count
	779	cmp.l #FCMAX,d0 * See it we've topped out
	780	bge tmi06 * Jump if limit was hit
	781	*
	782	addq.l #1,d0 * Count up 1 frame
	783	move.l d0,fc_val * Store updated frame count
	784	bra tmi04 * Done
	785	*
	786	tmi06: move.l #FCMAX,fc_val * Force hard limit, just in case
	787	bra tmi04 * Done
	788	*
	789	tmi05: move.l fc_val,d0 * Get the frame count
	790	beq tmi04 * Done if already zero
	791	*
	792	subq.l #1,d0 * Count down 1 frame
	793	move.l d0,fc_val * Store udpated frame count
	794	*
	795	movea.l timevec,a0 * Do RTC vector
	796	move.w #1,-(a7) * ... pass 1 msec on stack
	797	jsr (a0) * ...
	798	addq.l #4,a7 * ...
	799	*
	800	tmi04: movem.l (a7)+,d0-d7/a0-a6 * Restore registers
	801	rte * Return to interrupted code
	802	*
	803	.endc
	804	*
	805	.page
	806	*
	807	* trap14 -- Extended BIOS entry point
	808	* ------ -------------------------
	809	trap14: lea t14tab,a0 * Setup trap 14 table address
	810	bra trapent * Go process trap
	811	*
	812	* trap13 -- Main BIOS entry point
	813	* ------ ---------------------
	814	trap13: lea t13tab,a0 * Setup trap 13 table address
	815	*
	816	trapent: move.l savptr,a1 * Get save area pointer
	817	move.w (a7)+,d0 * Status register to D0
	818	move.w d0,-(a1) * Save in save area
	819	move.l (a7)+,-(a1) * Stash PC in save area
	820	movem.l d3-d7/a3-a7,-(a1) * Save parameter register
	821	move.l a1,savptr * Update save pointer
	822	btst #13,d0 * Were we in sup. mode ?
	823	bne trwzsup * Jump if so
	824	*
	825	move.l usp,a7 * Move user sp to stack ptr.
	826	*
	827	trwzsup: move.w (a7)+,d0 * Get function number from stack
	828	cmp.w (a0)+,d0 * Check against limit
	829	bge trpexit * Jump if it's invalid
	830	*
	831	lsl.w #2,d0 * Multiply by 4 for use as index
	832	move.l 0(a0,d0),d0 * Get routine address
	833	move.l d0,a0 * ... into a0
	834	bpl trpnind * Jump if it's indirect
	835	*
	836	move.l (a0),a0 * Use indirect value
	837	*
	838	trpnind: sub.l a5,a5 * Clear a5
	839	jsr (a0) * Execute the routine
	840	*
	841	trpexit: move.l savptr,a1 * Get SAVPTR into a1
	842	movem.l (a1)+,d3-d7/a3-a7 * Restore registers
	843	move.l (a1)+,-(a7) * Push return onto stack
	844	move.w (a1)+,-(a7) * Push status onto stack
	845	move.l a1,savptr * Update SAVPTR
	846	*
	847	* nullrte -- null rte
	848	* ------- --------
	849	nullrte: rte * Return to interrupted code
	850	*
	851	* nullrts -- null return
	852	* ------- -----------
	853	nullrts: rts * Just return to the caller
	854	*
	855	.page
	856	*
	857	* bconstat -- Get character device input status
	858	* -------- ---------------------------------
	859	bconstat: lea cdt01,a0 * Point at status table
	860	bra condisp * Jump to dispatcher
	861	*
	862	* bconin -- Get input from character device
	863	* ------ -------------------------------
	864	bconin: lea cdt02,a0 * Point at input table
	865	bra condisp * Jump to dispatcher
	866	*
	867	* bconout -- Output to character device
	868	* ------- --------------------------
	869	bconout: lea cdt03,a0 * Point at output table
	870	bra condisp * Jump to dispatcher
	871	*
	872	* bcostat -- Get character device output status
	873	* ------- ----------------------------------
	874	bcostat: lea cdt04,a0 * Point at status table
	875	*
	876	* condisp -- Character device function dispatcher
	877	* ------- ------------------------------------
	878	condisp: move.w 4(a7),d0 * Get device number
	879	lsl.w #2,d0 * ... times 4 for pointer
	880	move.l 0(a0,d0),a0 * Get routine address
	881	jmp (a0) * Jump to it
	882	*
	883	.page
	884	*
	885	* sr1ist -- Check CON (Serial-1) input buffer status
	886	* ------ ----------------------------------------
	887	sr1ist: lea sr1iorec,a0 * Address of iorec to a0
	888	lea SR1ACIA,a1 * Address of ACIA to a1
	889	bra chkist * Go check buffer status
	890	*
	891	* sr2ist -- Check AUX (Serial-2) input buffer status
	892	* ------ ----------------------------------------
	893	sr2ist: lea sr2iorec,a0 * Address of iorec to a0
	894	lea SR2ACIA,a1 * Address of ACIA to a1
	895	*
	896	.ifne BUCHLA
	897	*
	898	bra chkist * Go check buffer status
	899	*
	900	* mc1ist -- Check MC1 (MIDI-1) input buffer status
	901	* ------ --------------------------------------
	902	mc1ist: lea mc1iorec,a0 * Address of iorec to a0
	903	lea MC1ACIA,a1 * Address of ACIA to a1
	904	bra chkist * Go check buffer status
	905	*
	906	* mc2ist -- Check MC2 (MIDI-2) input buffer status
	907	* ------ --------------------------------------
	908	mc2ist: lea mc2iorec,a0 * Address of iorec to a0
	909	lea MC2ACIA,a1 * Address of ACIA to a1
	910	*
	911	.endc
	912	*
	913	* chkist -- Check input buffer status
	914	* ------ -------------------------
	915	chkist: moveq.l #-1,d0 * Default to "Input available"
	916	lea ibufhd(a0),a2 * Head index to a2
	917	lea ibuftl(a0),a3 * Tail index to a3
	918	cmpm.w (a3)+,(a2)+ * Buffer clear ?
	919	bne chkist1 * Jump if not
	920	*
	921	moveq.l #0,d0 * Set to "Buffer empty"
	922	*
	923	chkist1: rts * Return to caller
	924	*
	925	.page
	926	*
	927	* sr1ost -- Check CON (Serial-1) output buffer status
	928	* ------ -----------------------------------------
	929	sr1ost: lea sr1iorec,a0 * Address of iorec to a0
	930	bra chkost * Go check buffer status
	931	*
	932	* sr2ost -- Check AUX (Serial-2) output buffer status
	933	* ------ -----------------------------------------
	934	sr2ost: lea sr2iorec,a0 * Address of iorec to a0
	935	*
	936	.ifne BUCHLA
	937	*
	938	bra chkost * Go check buffer status
	939	*
	940	* mc1ost -- Check MC1 (MIDI-1) output buffer status
	941	* ------ ---------------------------------------
	942	mc1ost: lea mc1iorec,a0 * Address of iorec to a0
	943	bra chkost * Go check buffer status
	944	*
	945	* mc2ost -- Check MC2 (MIDI-2) output buffer status
	946	* ------ ---------------------------------------
	947	mc2ost: lea mc2iorec,a0 * Address of iorec to a0
	948	*
	949	.endc
	950	*
	951	* chkost -- Check output buffer status
	952	* ------ --------------------------
	953	chkost: moveq.l #-1,d0 * Default to "Output OK"
	954	move.w obuftl(a0),d2 * Tail index to d2
	955	bsr wrapout * Test for pointer wraparound
	956	cmp.w obufhd(a0),d2 * Compare with head index
	957	bne chkost1 * Jump if not equal
	958	*
	959	moveq.l #0,d0 * Set to "Buffer full"
	960	*
	961	chkost1: rts * Return to caller
	962	*
	963	.page
	964	*
	965	* wrapin -- Check input pointer for wraparound
	966	* ------ ----------------------------------
	967	wrapin: add.w #1,d1 * Head index +1
	968	cmp.w ibufsize(a0),d1 * = buffer size ?
	969	bcs wrapin1 * Jump if not
	970	*
	971	moveq.l #0,d1 * Wraparound
	972	*
	973	wrapin1: rts * Return to caller
	974	*
	975	* wrapout -- Check output pointer for wraparound
	976	* ------- -----------------------------------
	977	wrapout: addq.w #1,d2 * Tail index +1
	978	cmp.w obufsize(a0),d2 * = buffer size ?
	979	bcs wrapout1 * Jump if not
	980	*
	981	moveq.l #0,d2 * Wrap around if so
	982	*
	983	wrapout1: rts * Return to caller
	984	*
	985	.page
	986	*
	987	* sr1inp -- Get input from Serial-1 (wait on busy)
	988	* ------ ---------------------------------------
	989	sr1inp: lea sr1iorec,a0 * Serial-1 iorec address
	990	lea SR1ACIA,a1 * Serial-1 ACIA base
	991	bra serinp * Go get a byte
	992	*
	993	* sr2inp -- Get input from Serial-2 (wait on busy)
	994	* ------ ---------------------------------------
	995	sr2inp: lea sr2iorec,a0 * Serial-2 iorec address
	996	lea SR2ACIA,a1 * Serial-2 ACIA base
	997	*
	998	* serinp -- Get a byte from a serial port (with handshaking)
	999	* ------ -------------------------------------------------
	1000	serinp: bsr chkist * Check input status
	1001	tst.w d0 * Character ready ?
	1002	beq serinp * Loop until one is ...
	1003	*
	1004	bsr getser * Get a byte from the buffer
	1005	and.w #$FFFF,d0 * Isolate LS bits 7..0
	1006	rts * Return to caller
	1007	*
	1008	.page
	1009	*
	1010	.ifne BUCHLA
	1011	*
	1012	* mc1inp -- Get input from MIDI-1 (wait on busy)
	1013	* ------ -------------------------------------
	1014	mc1inp: lea mc1iorec,a0 * MIDI-1 iorec address
	1015	lea MC1ACIA,a1 * MIDI-1 ACIA base
	1016	bra midinp * Go get a byte
	1017	*
	1018	* mc2inp -- Get input from MIDI-2 (wait on busy)
	1019	* ------ -------------------------------------
	1020	mc2inp: lea mc2iorec,a0 * MIDI-2 iorec address
	1021	lea MC2ACIA,a1 * MIDI-2 ACIA base
	1022	*
	1023	* midinp -- Get input from a MIDI port (no handshaking)
	1024	* ------ --------------------------------------------
	1025	midinp: bsr chkist * Check input status
	1026	tst.w d0 * Character ready ?
	1027	beq midinp * Loop until one is ...
	1028	*
	1029	move.w sr,-(a7) * Save status register
	1030	ori.w #IPL7,sr * Set IPL = 7 (disable ints)
	1031	move.w ibufhd(a0),d1 * Head index to d1
	1032	cmp.w ibuftl(a0),d1 * Compare to tail index
	1033	beq midin_1 * Jump if (somehow) empty
	1034	*
	1035	addq.w #1,d1 * Increment head index
	1036	cmp.w ibufsize(a0),d1 * Did pointer wrap around ?
	1037	bcs midin_2 * Jump if not
	1038	*
	1039	moveq.l #0,d1 * Wraparound
	1040	*
	1041	midin_2: move.l ibuf(a0),a2 * Get buffer base address in a2
	1042	moveq.l #0,d0 * Clear MS bits of d0
	1043	move.b 0(a2,d1),d0 * Get character from buffer
	1044	move.w d1,ibufhd(a0) * Update buffer head index
	1045	*
	1046	midin_1: move.w (a7)+,sr * Restore status
	1047	rts * Return to caller
	1048	*
	1049	.endc
	1050	*
	1051	.page
	1052	*
	1053	* getser -- Get a byte from a serial port buffer (with handshaking)
	1054	* ------ --------------------------------------------------------
	1055	getser: move.w sr,-(a7) * Save status register
	1056	ori.w #IPL7,sr * Set IPL = 7 (disable ints)
	1057	move.w ibufhd(a0),d1 * Get input buffer head index
	1058	cmp.w ibuftl(a0),d1 * Compare tail index
	1059	beq rs_mt * Jump if buffer empty
	1060	*
	1061	bsr wrapin * Adjust pointer for wraparound
	1062	move.l ibuf(a0),a2 * Get buffer address
	1063	moveq.l #0,d0 * Clear out MS bits of d0
	1064	move.b 0(a2,d1),d0 * Get character from buffer
	1065	move.w d1,ibufhd(a0) * Update head index
	1066	move.w (a7)+,sr * Restore status
	1067	andi #$FFFE,sr * Clear carry = OK
	1068	bra rs_xnf * Go do XON/XOFF check
	1069	*
	1070	rs_mt: move.w (a7)+,sr * Restore status
	1071	ori #$0001,sr * Set carry = no character there
	1072	*
	1073	rs_xnf: btst #0,linedisc(a0) * Check for XON/XOFF mode
	1074	beq rs_exit * Jump if not enabled
	1075	*
	1076	tst.b flagxon(a0) * XON active ?
	1077	beq rs_exit * Jump if not
	1078	*
	1079	bsr rsilen * Get length of buffer used
	1080	cmp.w ibuflow(a0),d2 * At low water mark ?
	1081	bne rs_exit * Jump if not
	1082	*
	1083	move.b #$11,d1 * Send an XON
	1084	bsr serput * ...
	1085	clr.b flagxon(a0) * Clear XON flag
	1086	*
	1087	rs_exit: rts * Return to caller
	1088	*
	1089	.page
	1090	*
	1091	* sr1out -- Output to serial-1
	1092	* ------ ------------------
	1093	sr1out: lea sr1iorec,a0 * Serial-1 iorec address to a0
	1094	lea SR1ACIA,a1 * Serial-1 ACIA address to a1
	1095	move.w 6(a7),d1 * Get data byte from stack
	1096	bsr serput * Attempt to output
	1097	bcs sr1out * Try until it works ...
	1098	*
	1099	rts * Return to caller
	1100	*
	1101	* sr2out -- Output to Serial-2
	1102	* ------ ------------------
	1103	sr2out: lea sr2iorec,a0 * Serial-2 iorec address to a0
	1104	lea SR2ACIA,a1 * Serial-2 ACIA address to a1
	1105	move.w 6(a7),d1 * Get data byte from stack
	1106	bsr serput * Attempt to output
	1107	bcs sr2out * Try until it works ...
	1108	*
	1109	rts * Return to caller
	1110	*
	1111	.ifne BUCHLA
	1112	*
	1113	* mc1out -- Output to MIDI-1
	1114	* ------ ----------------
	1115	mc1out: lea mc1iorec,a0 * MIDI-1 iorec address to a0
	1116	lea MC1ACIA,a1 * MIDI-1 ACIA address to a1
	1117	move.w 6(a7),d1 * Get data byte from stack
	1118	bsr midput * Attempt to output
	1119	bcs mc1out * Try until it works ...
	1120	*
	1121	rts * Return to caller
	1122	*
	1123	* mc2out -- Output to MIDI-2
	1124	* ------ ----------------
	1125	mc2out: lea mc2iorec,a0 * MIDI-2 iorec address to a0
	1126	lea MC2ACIA,a1 * MIDI-2 ACIA address to a1
	1127	move.w 6(a7),d1 * Get data byte from stack
	1128	bsr midput * Attempt to output
	1129	bcs mc2out * Try until it works ...
	1130	*
	1131	rts * Return to caller
	1132	*
	1133	.endc
	1134	*
	1135	.page
	1136	*
	1137	* serput -- Output a character to a serial port
	1138	* ------ -----------------------------------
	1139	serput: move.w sr,-(a7) * Save status register
	1140	ori.w #IPL7,sr * Set IPL = 7 (disable ints)
	1141	move.b ACIA_ISR(a1),isr(a0) * Get ACIA isr
	1142	move.b ACIA_CSR(a1),csr(a0) * Get ACIA csr
	1143	btst #0,linedisc(a0) * XON/XOFF mode ?
	1144	beq serpt_1 * Jump if not
	1145	*
	1146	tst.b flagxoff(a0) * XON active ?
	1147	bne serpt_2 * Jump if so
	1148	*
	1149	serpt_1: btst.b #6,isr(a0) * Is ACIA still sending ?
	1150	beq serpt_2 * Jump if so
	1151	*
	1152	move.w obufhd(a0),d2 * Head index to d2
	1153	cmp.w obuftl(a0),d2 * Compare to tail index
	1154	bne serpt_2 * Jump if buffer not empty
	1155	*
	1156	move.b d1,ACIA_TDR(a1) * Give byte to ACIA to send
	1157	bra serpt_3 * Go deal with RTS/CTS if needed
	1158	*
	1159	serpt_2: move.w obuftl(a0),d2 * Tail index to d2
	1160	bsr wrapout * Adjust for wraparound
	1161	cmp.w obufhd(a0),d2 * Compare to head index
	1162	beq serpt_4 * Jump if buffer full
	1163	*
	1164	move.l obuf(a0),a2 * Get buffer base address in a2
	1165	move.b d1,0(a2,d2) * Put character in buffer
	1166	move.w d2,obuftl(a0) * Update buffer tail index
	1167	*
	1168	serpt_3: bsr serchk * Check status on our way out
	1169	bsr rtschk * Handle RTS protocol
	1170	move.w (a7)+,sr * Restore status register
	1171	andi #$FFFE,sr * Clear carry flag = OK
	1172	rts * Return to caller
	1173	*
	1174	serpt_4: bsr serchk * Check status on our way out
	1175	bsr rtschk * Handle RTS protocol
	1176	move.w (a7)+,sr * Restore status register
	1177	ori #$0001,sr * Set carry flag = buffer full
	1178	rts * Return to caller
	1179	*
	1180	.page
	1181	*
	1182	.ifne BUCHLA
	1183	*
	1184	* midput -- Output to MIDI
	1185	* ------ --------------
	1186	midput: move.w sr,-(a7) * Save status register
	1187	ori.w #IPL7,sr * Set IPL = 7 (diable ints)
	1188	move.b ACIA_ISR(a1),isr(a0) * Get ACIA isr
	1189	move.b ACIA_CSR(a1),csr(a0) * Get ACIA csr
	1190	btst.b #6,isr(a0) * Is ACIA still sending ?
	1191	beq midpt_2 * Jump if so
	1192	*
	1193	move.w obufhd(a0),d2 * Head index to d2
	1194	cmp.w obuftl(a0),d2 * Compare to tail index
	1195	bne midpt_2 * Jump if buffer not empty
	1196	*
	1197	move.b d1,ACIA_TDR(a1) * Give byte to ACIA to send
	1198	bra midpt_3 * Go set final status and exit
	1199	*
	1200	midpt_2: move.w obuftl(a0),d2 * Tail index to d2
	1201	bsr wrapout * Adjust for wraparound
	1202	cmp.w obufhd(a0),d2 * Compare to head index
	1203	beq midpt_4 * Jump if buffer full
	1204	*
	1205	move.l obuf(a0),a2 * Get buffer base address in a2
	1206	move.b d1,0(a2,d2) * Put character in buffer
	1207	move.w d2,obuftl(a0) * Update buffer tail index
	1208	*
	1209	midpt_3: bsr midchk * Check status on our way out
	1210	move.w (a7)+,sr * Restore status register
	1211	andi #$FFFE,sr * Clear carry flag = OK
	1212	rts * Return to caller
	1213	*
	1214	midpt_4: bsr midchk * Check status on our way out
	1215	move.w (a7)+,sr * Restore status register
	1216	ori #$0001,sr * Set carry flag = buffer full
	1217	rts * Return to caller
	1218	*
	1219	.endc
	1220	*
	1221	.page
	1222	*
	1223	* rtschk -- Check RTS mode and turn on RTS if it's enabled
	1224	* ------ ----------------------------------------------
	1225	rtschk: btst #1,linedisc(a0) * RTS/CTS mode set ?
	1226	beq rts_1 * Jump if not
	1227	*
	1228	bsr rtson * Turn on RTS
	1229	*
	1230	rts_1: rts * Return to caller
	1231	*
	1232	* rsilen -- Get length of portion of input buffer that's been used so far
	1233	* ------ -------------------------------------------------------------
	1234	rsilen: move.w ibuftl(a0),d2 * Tail index to d2
	1235	move.w ibufhd(a0),d3 * Head index to d3
	1236	cmp.w d3,d2 * Head > Tail ?
	1237	bhi rsi_1 * Jump if not
	1238	*
	1239	add.w ibufsize(a0),d2 * Add buffer size to tail index
	1240	*
	1241	rsi_1: sub.w d3,d2 * Length = (adjusted)Tail - Head
	1242	rts * Return to caller
	1243	*
	1244	* rtson -- Turn on RTS line
	1245	* ----- ----------------
	1246	rtson: move.b cfr1(a0),d0 * Pick up CFR1 image
	1247	bclr #0,d0 * Turn on RTS line (active low)
	1248	bset #7,d0 * Make sure MS bit is set
	1249	move.b d0,cfr1(a0) * Update CFR1 image
	1250	move.b d0,ACIA_CFR(a1) * Send CFR to hardware
	1251	rts * Return to caller
	1252	*
	1253	* rtsoff -- Turn off RTS line
	1254	* ------ -----------------
	1255	rtsoff: move.b cfr1(a0),d0 * Pick up CFR1 image
	1256	bset #0,d0 * Turn off RTS line (active low)
	1257	bset #7,d0 * Make sure MS bit is set
	1258	move.b d0,cfr1(a0) * Update CFR1 image
	1259	move.b d0,ACIA_CFR(a1) * Send CFR to hardware
	1260	rts
	1261	*
	1262	.page
	1263	*
	1264	* serintr -- Serial (Serial-1, Serial-2, MIDI-1, MIDI-2) interrupt handler
	1265	* ------- -------------------------------------------------------------
	1266	serintr: movem.l d0-d3/a0-a2,-(a7) * Save registers
	1267	lea sr1iorec,a0 * Point at Serial-1 iorec
	1268	lea SR1ACIA,a1 * Point at Serial-1 ACIA
	1269	bsr serint * Go process (possible) int.
	1270	*
	1271	lea sr2iorec,a0 * Point at Serial-2 iorec
	1272	lea SR2ACIA,a1 * Point at Serial-2 ACIA
	1273	bsr serint * Go process (possible) int.
	1274	*
	1275	.ifne BUCHLA
	1276	*
	1277	lea mc1iorec,a0 * Point at MIDI-1 iorec
	1278	lea MC1ACIA,a1 * Point at MIDI-1 ACIA
	1279	bsr midint * Go process (possible) int.
	1280	*
	1281	lea mc2iorec,a0 * Point at MIDI-2 iorec
	1282	lea MC2ACIA,a1 * Point at MIDI-2 ACIA
	1283	bsr midint * Go process (possible) int.
	1284	*
	1285	.endc
	1286	*
	1287	movem.l (a7)+,d0-d3/a0-a2 * Restore registers
	1288	rte * Return from exception
	1289	*
	1290	.page
	1291	*
	1292	* serint -- Process an interrupt from Serial-1 or Serial-2
	1293	* ------ ----------------------------------------------
	1294	serint: move.b ACIA_ISR(a1),isr(a0) * Get and save ISR
	1295	move.b ACIA_CSR(a1),csr(a0) * Get and save CSR
	1296	*
	1297	btst.b #7,isr(a0) * Was int for this device ?
	1298	beq serintx * Jump if not
	1299	*
	1300	serchk: btst.b #1,isr(a0) * FRM/OVR/BRK error ?
	1301	bne sererr * Jump if so
	1302	*
	1303	btst.b #0,isr(a0) * Receiver interrupt ?
	1304	bne serrx * Jump if so
	1305	*
	1306	sertxq: btst.b #6,isr(a0) * Transmitter interrupt ?
	1307	bne sertx * Jump if so
	1308	*
	1309	serctq: btst.b #5,isr(a0) * CTS interrupt ?
	1310	bne sercts * Jump if so
	1311	*
	1312	serintx: rts * Return to caller
	1313	*
	1314	sererr: addq.w #1,errct(a0) * Update error count
	1315	move.b ACIA_RDR(a1),erbyte(a0) * Get error byte
	1316	rts
	1317	*
	1318	* Handle CTS interupt
	1319	*
	1320	sercts: btst.b #1,linedisc(a0) * RTS/CTS mode ?
	1321	beq serintx * Ignore if not
	1322	*
	1323	btst.b #5,csr(a0) * CTS set ?
	1324	beq serintx * Ignore if not
	1325	*
	1326	sercts1: btst.b #6,isr(a0) * TDRE set ?
	1327	beq sercts1 * Loop until it is (!)
	1328	*
	1329	move.w obufhd(a0),d2 * Head index to d2
	1330	cmp.w obuftl(a0),d2 * Compare to tail index
	1331	beq serintx * Done if buffer empty
	1332	*
	1333	bsr.w wrapout * Adjust pointer for wraparound
	1334	move.l obuf(a0),a2 * Get buffer base in a2
	1335	move.b 0(a2,d2),ACIA_TDR(a1) * Send byte on its way
	1336	move.w d2,obufhd(a0) * Save updated head index
	1337	rts
	1338	*
	1339	.page
	1340	*
	1341	* Handle receiver interrupt
	1342	*
	1343	serrx: btst.b #1,linedisc(a0) * RTS/CTS mode set ?
	1344	beq serrx1 * Jump if not
	1345	*
	1346	bsr.w rtsoff * Turn off RTS
	1347	*
	1348	serrx1: move.b ACIA_RDR(a1),d0 * Read data from ACIA
	1349	btst.b #1,linedisc(a0) * RTS/CTS mode set ?
	1350	bne serrx3 * Jump if so
	1351	*
	1352	btst.b #0,linedisc(a0) * XON/XOFF mode set ?
	1353	beq serrx3 * Jump if not
	1354	*
	1355	cmpi.b #$11,d0 * Is this an XON ?
	1356	bne serrx2 * Jump if not
	1357	*
	1358	move.b #$00,flagxoff(a0) * Clear flagxoff
	1359	bra sertxq * Done
	1360	*
	1361	serrx2: cmpi.b #$13,d0 * Is this an XOFF ?
	1362	bne serrx3 * Jump if not
	1363	*
	1364	move.b #$FF,flagxoff(a0) * Set flagxoff
	1365	bra sertxq * Done
	1366	*
	1367	serrx3: move.w ibuftl(a0),d1 * Get tail index in d1
	1368	bsr.w wrapin * Adjust for wraparound
	1369	cmp.w ibufhd(a0),d1 * Head = tail ?
	1370	beq seribf * If so, we drop the character
	1371	*
	1372	move.l ibuf(a0),a2 * Get buffer address
	1373	move.b d0,0(a2,d1) * Stash byte in buffer
	1374	move.w d1,ibuftl(a0) * Save updated tail index
	1375	bsr rsilen * Get length of buffer used
	1376	cmp.w ibufhi(a0),d2 * Hit high water mark ?
	1377	bne serrx4 * Jump if not
	1378	*
	1379	btst.b #1,linedisc(a0) * RTS/CTS mode set ?
	1380	bne sertxq * Done if so
	1381	*
	1382	btst.b #0,linedisc(a0) * XON/XOFF mode set ?
	1383	beq serrx4 * Jump if not
	1384	*
	1385	tst.b flagxon(a0) * XOFF already sent ?
	1386	bne serrx4 * Jump if so
	1387	*
	1388	move.b #$FF,flagxon(a0) * Set the flag
	1389	move.b #$13,d1 * Send an XOFF
	1390	bsr.w serput * ...
	1391	*
	1392	.page
	1393	*
	1394	serrx4: btst #1,linedisc(a0) * RTS/CTS mode set ?
	1395	beq sertxq * Done if not
	1396	*
	1397	bsr rtson * Turn on RTS
	1398	bra sertxq
	1399	*
	1400	* Handle transmitter interrupt
	1401	*
	1402	sertx: btst.b #1,linedisc(a0) * RTS/CTS mode set ?
	1403	bne sertx2 * If so, go check CTS
	1404	*
	1405	btst.b #0,linedisc(a0) * XON/XOFF mode set ?
	1406	beq sertx1 * Jump if not
	1407	*
	1408	tst.b flagxoff(a0) * Check flagxoff
	1409	bne serctq * Done if set
	1410	*
	1411	sertx1: move.w obufhd(a0),d2 * Head index to d2
	1412	cmp.w obuftl(a0),d2 * Compare to tail index
	1413	beq serctq * Done if buffer empty
	1414	*
	1415	bsr wrapout * Adjust pointer for wraparound
	1416	move.l obuf(a0),a2 * Get buffer base address
	1417	move.b 0(a2,d2),ACIA_TDR(a1) * Send byte on its way
	1418	move.w d2,obufhd(a0) * Save updated head index
	1419	bra serctq * Done
	1420	*
	1421	sertx2: btst.b #5,csr(a0) * CTS set in csr ?
	1422	beq serctq * If not, go check for CTS int
	1423	*
	1424	bra sertx1 * CTS was set, go transmit
	1425	*
	1426	seribf: move.b d0,erbyte(a0) * Log dropped character
	1427	addq.w #1,ibfct(a0) * ...
	1428	bra sertxq * Go check Tx interrupt
	1429	*
	1430	.page
	1431	*
	1432	.ifne BUCHLA
	1433	*
	1434	* midint -- Process an interrupt from MIDI-1 or MIDI-2
	1435	* ------ ------------------------------------------
	1436	midint: move.b ACIA_ISR(a1),isr(a0) * Get and save ISR
	1437	move.b ACIA_CSR(a1),csr(a0) * Get and save CSR
	1438	*
	1439	btst.b #7,isr(a0) * Was int for this device ?
	1440	beq midintx * Jump if not
	1441	*
	1442	midchk: btst.b #1,isr(a0) * FRM/OVR/BRK error ?
	1443	bne miderr * Jump if so
	1444	*
	1445	btst.b #0,isr(a0) * Receiver interrupt ?
	1446	bne midrx * Jump if so
	1447	*
	1448	midtxq: btst.b #6,isr(a0) * Transmitter interrupt ?
	1449	bne midtx * Jump if so
	1450	*
	1451	midintx: rts * Return to caller
	1452	*
	1453	miderr: addq.w #1,errct(a0) * Update error count
	1454	move.b ACIA_RDR(a1),erbyte(a0) * Get error byte
	1455	rts
	1456	*
	1457	* Handle receiver interrupt
	1458	*
	1459	midrx: move.b ACIA_RDR(a1),d0 * Read data from ACIA
	1460	move.w ibuftl(a0),d1 * Get tail index in d1
	1461	bsr.w wrapin * Adjust for wraparound
	1462	cmp.w ibufhd(a0),d1 * Head = tail ?
	1463	beq midibf * If so, we drop the character
	1464	*
	1465	move.l ibuf(a0),a2 * Get buffer address
	1466	move.b d0,0(a2,d1) * Stash byte in buffer
	1467	move.w d1,ibuftl(a0) * Save updated tail index
	1468	bra midtxq * Done (go check tx int)
	1469	*
	1470	.page
	1471	*
	1472	* Handle transmitter interrupt
	1473	*
	1474	midtx: move.w obufhd(a0),d2 * Head index to d2
	1475	cmp.w obuftl(a0),d2 * Compare to tail index
	1476	beq midintx * Done if buffer empty
	1477	*
	1478	bsr wrapout * Adjust pointer for wraparound
	1479	move.l obuf(a0),a2 * Get buffer base address
	1480	move.b 0(a2,d2),ACIA_TDR(a1) * Send byte on its way
	1481	move.w d2,obufhd(a0) * Save updated head index
	1482	bra midintx * Done
	1483	*
	1484	midibf: move.b d0,erbyte(a0) * Log dropped character
	1485	addq.w #1,ibfct(a0) * ...
	1486	bra midtxq * Go check Tx interrupt
	1487	*
	1488	.endc
	1489	*
	1490	.page
	1491	*
	1492	* setexec -- Set an exception vector
	1493	* ------- -----------------------
	1494	setexec: move.w 4(a7),d0 * Get vector number
	1495	lsl.w #2,d0 * .. times 4
	1496	sub.l a0,a0 * Clear a0
	1497	lea 0(a0,d0),a0 * Get address of old vector
	1498	move.l (a0),d0 * Move old vector to d0
	1499	move.l 6(a7),d1 * Pick up new vector
	1500	bmi setexec1 * Don't set if = -1
	1501	*
	1502	move.l d1,(a0) * Set new vector
	1503	*
	1504	setexec1: rts * Return to caller
	1505	*
	1506	* piorec -- Get pointer to iorec structure
	1507	* ------ ------------------------------
	1508	piorec: moveq.l #0,d1 * Clear out d1
	1509	move.w 4(a7),d1 * Get device number
	1510	move.w sr,-(a7) * Save status register
	1511	ori.w #IPL7,sr * Set IPL = 7 (no ints)
	1512	lea iortab,a2 * Get base address of table
	1513	asl.l #2,d1 * Device # times 4 for index
	1514	move.l 0(a2,d1),d0 * Get iorec address from table
	1515	move.w (a7)+,sr * Restore status register
	1516	rts * Return to caller
	1517	*
	1518	.page
	1519	*
	1520	* setport -- Set ACIA parameters (unit, mode, baud, CFR0, CFR1)
	1521	* ------- ---------------------------------------------------
	1522	setport: moveq.l #0,d1 * Clear out d1
	1523	move.w 4(a7),d1 * Get device number
	1524	asl.l #3,d1 * Times 8 for index
	1525	ori.w #IPL7,sr * Set IPL = 7 (no ints)
	1526	lea aciatab,a2 * Get base of table
	1527	move.l 0(a2,d1),d0 * Get iorec address
	1528	move.l 4(a2,d1),d2 * Get ACIA address
	1529	movea.l d0,a0 * Setup a0 = iorec address
	1530	movea.l d2,a1 * Setup a1 = ACIA address
	1531	tst.w 6(a7) * Change mode ?
	1532	bmi setpt1 * Jump if not
	1533	*
	1534	move.b 7(a7),linedisc(a0) * Set line discipline (mode)
	1535	*
	1536	setpt1: tst.w 8(a7) * Change baud rate ?
	1537	bmi setpt2 * Jump if not
	1538	*
	1539	moveq.l #0,d1 * Clear out d1
	1540	move.w 8(a7),d1 * Get baud rate index
	1541	lea brtable,a2 * Get base of baud rate table
	1542	move.b 0(a2,d1),d2 * Get baud rate code from table
	1543	move.b cfr0(a0),d0 * Get current CFR0
	1544	andi.w #$0070,d0 * Mask off old baud rate code
	1545	or.w d2,d0 * OR in new baud rate code
	1546	move.b d0,cfr0(a0) * Update CFR0 in table
	1547	move.b d0,ACIA_CFR(a1) * Update hardware
	1548	*
	1549	setpt2: tst.w 10(a7) * Change CFR0 ?
	1550	bmi setpt3 * Jump if not
	1551	*
	1552	move.b 11(a7),cfr0(a0) * Update CFR0 in table
	1553	move.b cfr0(a0),ACIA_CFR(a1) * Update CFR0 in hardware
	1554	*
	1555	setpt3: tst.w 12(a7) * Change CFR1 ?
	1556	bmi setpt4 * Jump if not
	1557	*
	1558	bset.b #7,13(a7) * Force D7 = 1 in argument
	1559	move.b 13(a7),cfr1(a0) * Update CFR1 in table
	1560	move.b cfr1(a0),ACIA_CFR(a1) * Update CFR1 in hardware
	1561	*
	1562	setpt4: rts * Return to caller
	1563	*
	1564	.page
	1565	*
	1566	* aciainit -- Initialize an ACIA port
	1567	* -------- -----------------------
	1568	aciainit: move.w #IORECLN,d0 * Setup byte count for move
	1569	move.l a0,-(a7) * Save iorec base
	1570	*
	1571	aciai_1: move.b (a2)+,(a0)+ * Move the default to the iorec
	1572	dbf d0,aciai_1 * ...
	1573	*
	1574	move.l (a7)+,a0 * Restore iorec base
	1575	move.b cfr0(a0),ACIA_CFR(a1) * Setup CFR0
	1576	move.b cfr1(a0),ACIA_CFR(a1) * Setup CFR1
	1577	move.b ACIA_RDR(a1),d0 * Clear RDR
	1578	move.b #$7F,ACIA_IER(a1) * Disable all interrupts
	1579	btst.b #1,linedisc(a0) * Are we in RTS/CTS mode ?
	1580	bne aciai_2 * Jump if so
	1581	*
	1582	move.b #$C3,ACIA_IER(a1) * Enable TDRE, RDRF
	1583	bra aciai_3 * Go return
	1584	*
	1585	aciai_2: move.b #$E3,ACIA_IER(a1) * Enable interrupts we want
	1586	*
	1587	aciai_3: rts * Return to caller
	1588	*
	1589	.page
	1590	*
	1591	.ifne BUCHLA
	1592	*
	1593	* fastcopy -- Copy disk sector quickly
	1594	* -------- ------------------------
	1595	fastcopy: move.l 4(a7),a0 * Get source pointer
	1596	move.l 8(a7),a1 * Get destination pointer
	1597	move.w $3F,d0 * 512 bytes (63+1)*8
	1598	*
	1599	fastcpy1: move.b (a0)+,(a1)+ * Move 8 bytes
	1600	move.b (a0)+,(a1)+ * ...
	1601	move.b (a0)+,(a1)+ * ...
	1602	move.b (a0)+,(a1)+ * ...
	1603	move.b (a0)+,(a1)+ * ...
	1604	move.b (a0)+,(a1)+ * ...
	1605	move.b (a0)+,(a1)+ * ...
	1606	move.b (a0)+,(a1)+ * ...
	1607	dbra d0,fastcpy1 * Loop until all bytes are moved
	1608	*
	1609	rts * Return to caller
	1610	*
	1611	.page
	1612	*
	1613	* _hdvini -- Drive initialization
	1614	* ------- --------------------
	1615	_hdvini: link a6,#-18 * Reserve space on stack
	1616	movem.l d3-d7/a3-a5,-(a7) * Preserve registers
	1617	move.l #300,maxactim * maxactim = 300 * 20ms
	1618	clr.w d0 * Put zeros in ...
	1619	move.w d0,nflops * ... nflops
	1620	move.w d0,dskmode * ... dskmode
	1621	move.w d0,-2(a6) * Start with drive A
	1622	bra hdvilp * ...
	1623	*
	1624	hdvilp1: movea.l #dskmode,a0 * Get dskmode address in a0
	1625	movea.w -2(a6),a1 * Drive number in a1
	1626	adda.l a1,a0 * Point at dskmode for drive
	1627	clr.b (a0) * Clear flag in dskmode
	1628	clr.w -(a7) * Push arguments onto stack
	1629	clr.w -(a7) * ...
	1630	clr.w -(a7) * ...
	1631	move.w -2(a6),-(a7) * Push drive number onto stack
	1632	clr.l -(a7) * ... filler
	1633	clr.l -(a7) * ... filler
	1634	jsr flopini * Initialize drive
	1635	adda.l #16,a7 * Cleanup stack
	1636	move.w d0,-(a7) * Save error code on stack
	1637	movea.w -2(a6),a0 * Get drive number
	1638	adda.l a0,a0 * ... times 2
	1639	adda.l #dskerrs,a0 * Add base of dskerrs
	1640	move.w (a7)+,(a0) * Move error code off of stack
	1641	bne hdvind * Jump if drive not present
	1642	*
	1643	addq.w #1,nflops * Update number of drives
	1644	or.l #3,drvbits * Setup drive bits
	1645	*
	1646	hdvind: addq.w #1,-2(a6) * Increment drive number
	1647	*
	1648	hdvilp: cmp.w #2,-2(a6) * See if it's 2 yet
	1649	blt hdvilp1 * Loop until it is
	1650	*
	1651	movem.l (a7)+,d3-d7/a3-a5 * Restore registers
	1652	unlk a6 * Release temporary stack space
	1653	rts * Return to caller
	1654	*
	1655	* drvmap -- get drive map
	1656	* ------ -------------
	1657	drvmap: move.l drvbits,d0 * Get drive bits
	1658	rts * Return to caller
	1659	*
	1660	.page
	1661	*
	1662	* getbpb -- get BIOS parameter block
	1663	* ------ ------------------------
	1664	getbpb: link a6,#-12 * Reserve space for temporaries
	1665	movem.l d5-d7/a4-a5,-(a7) * Save registers on stack
	1666	cmp.w #2,8(a6) * Check drive number
	1667	blt gbpb1 * Jump if OK
	1668	*
	1669	clr.l d0 * Set drive number to 0
	1670	bra gbpber * Go flag error
	1671	*
	1672	gbpb1: move.w 8(a6),d0 * Get drive number
	1673	asl.w #5,d0 * ... times 32
	1674	ext.l d0 * ... extend sign
	1675	move.l d0,a5 * Move to a5
	1676	add.l #drvbpbs,a5 * Add base of drive bpb are
	1677	move.l a5,a4 * Save in a4
	1678	*
	1679	gbpbrds: move.w #1,(a7) * floprd count = 1,
	1680	clr.w -(a7) * ... side = 0,
	1681	clr.w -(a7) * ... track = 0,
	1682	move.w #1,-(a7) * ... sector = 1,
	1683	move.w 8(a6),-(a7) * ... drive #,
	1684	clr.l -(a7) * ... filler
	1685	move.l #buffer,-(a7) * ... buffer address,
	1686	jsr floprd * Go read the sector
	1687	add.l #16,a7 * Cleanup stack
	1688	move.l d0,-12(a6) * Save error code
	1689	tst.l -12(a6) * ... and test it
	1690	bge gbpb2 * Jump if OK
	1691	*
	1692	move.w 8(a6),(a7) * Put drive number on stack
	1693	move.l -12(a6),d0 * Get error code
	1694	move.w d0,-(a7) * ... and put it on the stack
	1695	jsr criter * Go do critical error routine
	1696	addq.l #2,a7 * Cleanup stack
	1697	move.l d0,-12(a6) * Save error code
	1698	*
	1699	gbpb2: move.l -12(a6),d0 * Get error code
	1700	cmp.l #RETRYIT,d0 * Magic number for retry ?
	1701	beq gbpbrds * Re-read if so
	1702	*
	1703	tst.l -12(a6) * Test error code
	1704	bge gbpb3 * Jump if OK
	1705	*
	1706	clr.l d0 * Set code in d0
	1707	bra gbpber * Go set error code
	1708	*
	1709	.page
	1710	*
	1711	gbpb3: move.l #buffer+11,(a7) * Bytes per sector
	1712	bsr itom * Convert 8086 to 68K format
	1713	move.w d0,d7 * Save bytes per sector
	1714	beq gbpb4 * Jump if zero
	1715	*
	1716	move.b buffer+13,d6 * Sectors per cluster
	1717	ext.w d6 * ... sign extended
	1718	and.w #$FF,d6 * ... and trimmed
	1719	bne gbpb5 * Jump if non-zero
	1720	*
	1721	gbpb4: clr.l d0 * Set error code
	1722	bra gbpber * ...
	1723	*
	1724	gbpb5: move.w d7,(a4) * Set recsize
	1725	move.w d6,2(a4) * Set clsiz
	1726	move.l #buffer+22,(a7) * Convert sectors per fat
	1727	bsr itom * ...
	1728	move.w d0,8(a4) * Set fsiz
	1729	move.w 8(a4),d0 * Get fsiz
	1730	addq.w #1,d0 * ... plus 1
	1731	move.w d0,10(a4) * Set fatrec
	1732	move.w (a4),d0 * Get recsize
	1733	muls.w 2(a4),d0 * ... times clsiz
	1734	move.w d0,4(a4) * Set clsizb
	1735	move.l #buffer+17,(a7) * Convert number of dir ents
	1736	bsr itom * ...
	1737	asl.w #5,d0 * ... times 32
	1738	ext.l d0 * ... sign extended
	1739	divs.w (a4),d0 * ... / recsize
	1740	move.w d0,6(a4) * Set rdlen
	1741	move.w 10(a4),d0 * Get fatrec
	1742	add.w 6(a4),d0 * ... + rdlen
	1743	add.w 8(a4),d0 * ... + fsiz
	1744	move.w d0,12(a4) * Set datrec
	1745	move.l #buffer+19,(a7) * Get number of sectors
	1746	bsr itom * ... convert
	1747	sub.w 12(a4),d0 * ... - datrec
	1748	ext.l d0 * ... sign extended
	1749	divs.w 2(a4),d0 * ... / clsiz
	1750	move.w d0,14(a4) * Set numcl
	1751	*
	1752	.page
	1753	*
	1754	move.l #buffer+26,(a7) * Convert number of heads
	1755	bsr itom * ...
	1756	move.w d0,20(a5) * Set dnsides
	1757	move.l #buffer+24,(a7) * Convert sectors per track
	1758	bsr itom * ...
	1759	move.w d0,24(a5) * Set dspt
	1760	move.w 20(a5),d0 * Get dnsides
	1761	muls.w 24(a5),d0 * ... * dspt
	1762	move.w d0,22(a5) * Set dspc
	1763	move.l #buffer+28,(a7) * Convert number of hidden sects
	1764	bsr itom * ...
	1765	move.w d0,26(a5) * Set dhidden
	1766	move.l #buffer+19,(a7) * Convert sectors on disk
	1767	bsr itom * ...
	1768	ext.l d0 * ... sign extended
	1769	divs.w 22(a5),d0 * ... / dspc
	1770	move.w d0,18(a5) * Set dntracks
	1771	clr.w d7 * Counter = 0
	1772	bra gbpblpt * Jump to end of loop
	1773	*
	1774	gbpb6: move.l a5,a0 * Get buffer pointer
	1775	move.w d7,a1 * Loop count to a1
	1776	add.l a1,a0 * ... + bpb address
	1777	move.w d7,a1 * Loop count to a1
	1778	add.l #buffer,a1 * ... + buffer address
	1779	move.b 8(a1),28(a0) * Copy a s/n byte
	1780	addq.w #1,d7 * Update loop count
	1781	*
	1782	gbpblpt: cmp.w #3,d7 * Moved 3 bytes ?
	1783	blt gbpb6 * Loop if not
	1784	*
	1785	.page
	1786	*
	1787	move.l #cdev,a0 * Address of cdev table
	1788	move.w 8(a6),a1 * ... plus drive number
	1789	add.l a1,a0 * ... to a0
	1790	move.l #wpstatus,a1 * Address of wpstatus table
	1791	move.w 8(a6),a2 * ... plus drive number
	1792	add.l a2,a1 * ... to a1
	1793	move.b (a1),(a0) * Move wpstatus to cdev
	1794	beq gbpb7
	1795	*
	1796	moveq.l #1,d0 * Set status = "Uncertain"
	1797	bra gbpb8
	1798	*
	1799	gbpb7: clr.w d0 * Set status = "Unchanged"
	1800	*
	1801	gbpb8: move.l #dskmode,a1 * Update dskmode table
	1802	move.w 8(a6),a2 * ...
	1803	add.l a2,a1 * ...
	1804	move.b d0,(a1) * ...
	1805	move.l a5,d0 * Setup to return bpb pointer
	1806	*
	1807	gbpber: tst.l (a7)+ * Pop garbage off top of stack
	1808	movem.l (a7)+,d6-d7/a4-a5 * Restore registers
	1809	unlk a6
	1810	rts
	1811	*
	1812	.page
	1813	*
	1814	* mediach -- check for media change
	1815	* ------- ----------------------
	1816	mediach: link a6,#0 * Create scratch on stack
	1817	movem.l d6-d7/a5,-(a7) * Save registers on stack
	1818	cmp.w #2,8(a6) * Check drive number
	1819	blt media1 * Jump if OK
	1820	*
	1821	moveq.l #ERR15,d0 * Error -- "unknown device"
	1822	bra media2 * ...
	1823	*
	1824	media1: move.w 8(a6),d7 * Get drive number in d7
	1825	movea.w d7,a5 * Point into dskmode table
	1826	add.l #dskmode,a5 * ...
	1827	cmp.b #2,(a5) * Definitely changed ?
	1828	bne media3 * Jump if not
	1829	*
	1830	moveq.l #2,d0 * Setup to return "Changed"
	1831	bra media2 * Done -- go return to caller
	1832	*
	1833	media3: move.l #wplatch,a0 * Check wplatch for drive
	1834	tst.b 0(a0,d7) * ...
	1835	beq media4 * Jump if not set
	1836	*
	1837	move.b #1,(a5) * Set dskmode to "Uncertain"
	1838	*
	1839	media4: move.l _hz_200,d0 * Get time in d0
	1840	movea.w d7,a1 * Calculate acctim table address
	1841	add.l a1,a1 * ... = drive # * 4
	1842	add.l a1,a1 * ...
	1843	add.l #acctim,a1 * ... + acctim base address
	1844	move.l (a1),d1 * Get acctim for drive
	1845	sub.l d1,d0 * Subtract from current time
	1846	cmp.l maxactim,d0 * Timed out ?
	1847	bge media5 * Jump if so
	1848	*
	1849	clr.w d0 * Setup to return "Unchanged"
	1850	bra media2
	1851	*
	1852	media5: move.b (a5),d0 * Return status from dskmode
	1853	ext.w d0
	1854	*
	1855	media2: tst.l (a7)+ * Pop extra stack word
	1856	movem.l (a7)+,d7/a5 * Restore registers
	1857	unlk a6
	1858	rts * Return to caller
	1859	*
	1860	.page
	1861	*
	1862	* rwabs -- read / write sector(s)
	1863	* ----- ----------------------
	1864	rwabs: link a6,#-4 * Reserve stack for temps
	1865	movem.l d4-d7/a5,-(a7) * Save registers on stack
	1866	cmp.w #2,18(a6) * Drive number
	1867	blt rwabs1
	1868	*
	1869	moveq.l #ERR15,d0 * ERROR -- "unknown device"
	1870	bra rwabser
	1871	*
	1872	rwabs1: move.w 18(a6),d6 * Save drive number
	1873	cmp.w #2,8(a6) * Check rwflag
	1874	bge rwabs7
	1875	*
	1876	move.w d6,d0
	1877	asl.w #5,d0
	1878	ext.l d0
	1879	move.l d0,a5
	1880	add.l #drvbpbs,a5
	1881	move.w d6,(a7)
	1882	bsr mediach * Test for media change
	1883	move.w d0,d7 * Save status
	1884	cmp.w #2,d7 * Disk changed ?
	1885	bne rwabs2 * Jump if not
	1886	*
	1887	moveq.l #ERR14,d0 * ERROR -- "media changed"
	1888	bra rwabser * ...
	1889	*
	1890	rwabs2: cmp.w #1,d7 * Disk possibly changed ?
	1891	bne rwabs7
	1892	*
	1893	rwabs3: move.w #1,(a7) * floprd count = 1,
	1894	clr.w -(a7) * ... side = 0,
	1895	clr.w -(a7) * ... track = 0,
	1896	move.w #1,-(a7) * ... sector = 1,
	1897	move.w d6,-(a7) * ... drive number,
	1898	clr.l -(a7) * ... filler,
	1899	move.l #buffer,-(a7) * ... buffer address,
	1900	jsr floprd * Read boot sector
	1901	add.l #16,a7 * Cleanup stack
	1902	move.l d0,-4(a6) * Save error number
	1903	tst.l -4(a6) * ... and test it
	1904	bge rwabs11 * Jump if OK
	1905	*
	1906	.page
	1907	*
	1908	move.w d6,(a7)
	1909	move.l -4(a6),d0
	1910	move.w d0,-(a7)
	1911	jsr criter * Call critical error code
	1912	addq.l #2,a7 * Cleanup stack
	1913	move.l d0,-4(a6)
	1914	*
	1915	rwabs11: move.l -4(a6),d0
	1916	cmp.l #RETRYIT,d0
	1917	beq rwabs3 * Read again
	1918	*
	1919	tst.l -4(a6) * Test error number
	1920	bge rwabs4 * OK ?
	1921	*
	1922	move.l -4(a6),d0
	1923	bra rwabser * ERROR
	1924	*
	1925	rwabs4: clr.w d7 * Clear media change status
	1926	bra rwabs10
	1927	*
	1928	rwabs6: move.l #buffer,a0 * Address of sector buffer to a0
	1929	move.b 8(a0,d7),d0 * Serial number
	1930	ext.w d0
	1931	move.b 28(a5,d7),d1 * Compare to old one
	1932	ext.w d1
	1933	cmp.w d1,d0
	1934	beq rwabs5 * Jump if they're the same
	1935	*
	1936	moveq.l #ERR14,d0 * ERROR -- "media changed"
	1937	bra rwabser
	1938	*
	1939	rwabs5: addq.w #1,d7 * Next byte of serial number
	1940	*
	1941	rwabs10: cmp.w #3,d7 * All 3 bytes checked ?
	1942	blt rwabs6 * Loop if not
	1943	*
	1944	.page
	1945	*
	1946	move.w d6,a0 * Point at wplatch for drive
	1947	add.l #wplatch,a0 * ...
	1948	move.w d6,a1 * Point at wpstatus for drive
	1949	add.l #wpstatus,a1 * ...
	1950	move.b (a1),(a0) * Move wpstatus to wplatch
	1951	bne rwabs9 * Jump if set
	1952	*
	1953	move.w d6,a0 * Set dskmode to "Unchanged"
	1954	add.l #dskmode,a0 * ...
	1955	clr.b (a0) * ...
	1956	*
	1957	rwabs7: tst.w nflops * Test nflops
	1958	bne rwabs8
	1959	*
	1960	moveq.l #ERR02,d0 * ERROR -- "drive not ready"
	1961	bra rwabser
	1962	*
	1963	rwabs8: cmp.w #1,8(a6) * Check rwflag
	1964	ble rwabs9
	1965	*
	1966	subq.w #2,8(a6) * Adjust to 0\|1
	1967	*
	1968	rwabs9: move.w 14(a6),(a7) * Setup count,
	1969	move.w d6,-(a7) * ... drive,
	1970	move.w 16(a6),-(a7) * ... recno,
	1971	move.l 10(a6),-(a7) * ... buffer,
	1972	move.w 8(a6),-(a7) * ... rwflag
	1973	bsr floprw * Call floprw
	1974	*
	1975	add.l #10,a7 * Cleanup stack
	1976	*
	1977	rwabser: tst.l (a7)+ * Pop stack scratch
	1978	movem.l (a7)+,d5-d7/a5 * Restore registers
	1979	unlk a6 * Release temporaries
	1980	rts * Return to caller
	1981	*
	1982	.page
	1983	*
	1984	* floprw -- Floppy read / write driver
	1985	* ------ --------------------------
	1986	floprw: link a6,#-6 * Reserve space for temps
	1987	movem.l d2-d7/a5,-(a7) * Save registers
	1988	move.w 16(a6),d0 * Drive number to d0
	1989	asl.w #5,d0 * Shift ( *32 )
	1990	ext.l d0 * Sign extend it, too
	1991	move.l d0,a5 * Result in a5
	1992	add.l #drvbpbs,a5 * Add base of BPB table
	1993	btst #0,13(a6) * Buffer address even ?
	1994	bne floprw01 * Jump if not
	1995	*
	1996	clr.w d0 * Clear odd flag
	1997	bra floprw02 * Go save the flag
	1998	*
	1999	floprw01: moveq.l #1,d0 * Set odd flag
	2000	*
	2001	floprw02: move.w d0,-2(a6) * Save it
	2002	tst.w 22(a5) * dspc set ?
	2003	bne floprw20 * Jump if so
	2004	*
	2005	moveq.l #9,d0 * Assume 9
	2006	move.w d0,22(a5) * ... and make it the default
	2007	move.w d0,24(a5) * ... for dspt and dspc
	2008	*
	2009	floprw20: bra floprw18
	2010	*
	2011	floprw03: tst.w -2(a6) * Is odd flag set ?
	2012	beq floprw04 * Jump if not
	2013	*
	2014	move.l #buffer,d0 * Point to sector buffer
	2015	bra floprw05
	2016	*
	2017	floprw04: move.l 10(a6),d0 * Get buffer address
	2018	*
	2019	floprw05: move.l d0,-6(a6) * ... and save
	2020	move.w 14(a6),d6 * Get recno (lsn)
	2021	ext.l d6 * Extend it to long
	2022	divs.w 22(a5),d6 * Divide by dspc for track #
	2023	move.w 14(a6),d4 * Get recno
	2024	ext.l d4 * Extend to long
	2025	divs.w 22(a5),d4 * Divide by dspc
	2026	swap d4 * Use remainder as sector number
	2027	cmp.w 24(a5),d4 * Compare with dspt
	2028	bge floprw06 * Greater than or equal ?
	2029	*
	2030	clr.l d5 * Use side 0
	2031	bra floprw07
	2032	*
	2033	floprw06: moveq.l #1,d5 * Use side 1
	2034	sub.w 24(a5),d4 * Subtract dspt from sector #
	2035	*
	2036	.page
	2037	*
	2038	floprw07: tst.w -2(a6) * Is odd flag set ?
	2039	beq floprw08 * Jump if not
	2040	*
	2041	moveq.l #1,d3 * Set counter to 1
	2042	bra floprw10
	2043	*
	2044	floprw08: move.w 24(a5),d0 * Get dspt
	2045	sub.w d4,d0 * Subtract sector number
	2046	cmp.w 18(a6),d0 * Compare with number of sectors
	2047	bge floprw09 * Jump if greater than or eq to
	2048	*
	2049	move.w 24(a5),d3 * Get dspt
	2050	sub.w d4,d3 * Subtract sector number
	2051	bra floprw10
	2052	*
	2053	floprw09: move.w 18(a6),d3 * Count = number of sectors
	2054	*
	2055	floprw10: addq.w #1,d4 * Adjust sector number (1 org)
	2056	*
	2057	floprw11: tst.w 8(a6) * Test r/w flag
	2058	beq floprw14 * Jump if it's a read
	2059	*
	2060	move.l -6(a6),d0 * Get buffer pointer
	2061	cmp.l 10(a6),d0 * See if it's = buffer addr
	2062	beq floprw12 * Jump if so
	2063	*
	2064	move.l -6(a6),(a7) * Get source address
	2065	move.l 10(a6),-(a7) * Destination address
	2066	jsr fastcopy * Copy the sector
	2067	addq.l #4,a7 * Cleanup stack
	2068	*
	2069	floprw12: move.w d3,(a7) * Number of sectors
	2070	move.w d5,-(a7) * Side number
	2071	move.w d6,-(a7) * Track number
	2072	move.w d4,-(a7) * Sector number
	2073	move.w 16(a6),-(a7) * Drive number
	2074	clr.l -(a7) * Filler
	2075	move.l -6(a6),-(a7) * Buffer address
	2076	jsr flopwr * Write sector
	2077	add.l #16,a7 * Cleaup stack
	2078	move.l d0,d7 * Save error code in d7
	2079	tst.l d7 * Errors ?
	2080	bne floprw13 * Jump if so
	2081	*
	2082	.page
	2083	*
	2084	tst.w fverify * Verify after write ?
	2085	beq floprw13 * Jump if not
	2086	*
	2087	move.w d3,(a7) * Number of sectors
	2088	move.w d5,-(a7) * Side number
	2089	move.w d6,-(a7) * Track number
	2090	move.w d4,-(a7) * Sector number
	2091	move.w 16(a6),-(a7) * Drive number
	2092	clr.l -(a7) * Filler
	2093	move.l #buffer,-(a7) * Buffer address
	2094	jsr flopver * Verify sector(s)
	2095	add.l #16,a7 * Cleanup stack
	2096	move.l d0,d7 * Save error code in d7
	2097	tst.l d7 * Errors ?
	2098	bne floprw13 * Jump if so
	2099	*
	2100	move.l #buffer,(a7) * Address of sector buffer
	2101	bsr itom * Convert first word of buffer
	2102	tst.w d0 * Bad sectors ?
	2103	beq floprw13 * Jump if not
	2104	*
	2105	moveq.l #ERR16,d7 * ERROR -- "Bad sectors"
	2106	*
	2107	floprw13: bra floprw15
	2108	*
	2109	.page
	2110	*
	2111	floprw14: move.w d3,(a7) * Number of sectors
	2112	move.w d5,-(a7) * Side number
	2113	move.w d6,-(a7) * Track number
	2114	move.w d4,-(a7) * Sector number
	2115	move.w 16(a6),-(a7) * Drive number
	2116	clr.l -(a7) * Filler
	2117	move.l -6(a6),-(a7) * Sector buffer
	2118	jsr floprd * Read floppy sector(s)
	2119	add.l #16,a7 * Cleanup stack
	2120	move.l d0,d7 * Save error code in d7
	2121	move.l -6(a6),d0 * User buffer address
	2122	cmp.l 10(a6),d0 * Is it the desired buffer ?
	2123	beq floprw15 * Jump if so
	2124	*
	2125	move.l 10(a6),(a7) * Push source address
	2126	move.l -6(a6),-(a7) * Push destination address
	2127	jsr fastcopy * Copy the sector
	2128	addq.l #4,a7 * Cleanup stack
	2129	*
	2130	floprw15: tst.l d7 * Error code set ?
	2131	bge floprw16 * Jump if not
	2132	*
	2133	move.w 16(a6),(a7) * Push drive number
	2134	move.l d7,d0 * Error code
	2135	move.w d0,-(a7) * ... onto stack
	2136	jsr criter * Call critical error handler
	2137	addq.l #2,a7 * Cleanup stack
	2138	move.l d0,d7 * Get error code
	2139	*
	2140	floprw16: cmp.l #RETRYIT,d7 * Re-try ?
	2141	beq floprw11 * Jump if so
	2142	*
	2143	tst.l d7 * Check error code
	2144	bge floprw17 * Jump if no error
	2145	*
	2146	move.l d7,d0 * Error code is the result
	2147	bra floprw19
	2148	*
	2149	.page
	2150	*
	2151	floprw17: move.w d3,d0 * Sector counter to d0
	2152	ext.l d0 * Sign extend
	2153	moveq.l #9,d1 * Times 512
	2154	asl.l d1,d0 * ...
	2155	add.l d0,10(a6) * Update buffer address
	2156	add.w d3,14(a6) * Update sector number
	2157	sub.w d3,18(a6) * Update sector count
	2158	*
	2159	floprw18: tst.w 18(a6) * More sectors ?
	2160	bne floprw03 * Jump if so
	2161	*
	2162	clr.l d0 * Set "no error" as result
	2163	*
	2164	floprw19: tst.l (a7)+ * Test top of stack
	2165	movem.l (a7)+,d3-d7/a5 * Restore registers
	2166	unlk a6 * Release stack space
	2167	rts * Return to caller
	2168	*
	2169	.page
	2170	*
	2171	* itom -- Convert 8086 integer format to 680000 integer format
	2172	* ---- ----------------------------------------------------
	2173	itom: link a6,#-4 * Reserve stack for temps
	2174	move.l 8(a6),a0 * Address of the number to a0
	2175	move.b 1(a0),d0 * Get high byte
	2176	ext.w d0 * Make it a word
	2177	and.w #$FF,d0 * Isolate bits 0..7
	2178	asl.w #8,d0 * Shift in bits 8..15
	2179	move.l 8(a6),a1 * Address of the number to a1
	2180	move.b (a1),d1 * Get low byte
	2181	ext.w d1 * Extend to word
	2182	and.w #$FF,d1 * Isolate bits 0..7
	2183	or.w d1,d0 * Combine with bits 8..15
	2184	unlk a6 * Release stack space
	2185	rts * Return to caller
	2186	*
	2187	.page
	2188	*
	2189	* flopini -- Initialize floppy drive
	2190	* ------- -----------------------
	2191	flopini: lea dsb0,a1 * Point to dsb for drive A
	2192	tst.w 12(a7) * Drive A wanted ?
	2193	beq flopin01 * Jump if so
	2194	*
	2195	lea dsb1,a1 * Drive B dsb address to a1
	2196	*
	2197	flopin01: move.w seekrate,2(a1) * Get seek rate
	2198	moveq.l #ERR01,d0 * Set default error number
	2199	clr.w 0(a1) * Set track number to 0
	2200	bsr floplock * Setup floppy parameters
	2201	bsr select * Select drive and side
	2202	move.w #$FF00,0(a1)
	2203	bsr restore * Restore the drive
	2204	moveq.l #6,d7
	2205	bsr hseek1
	2206	bne flopin02
	2207	*
	2208	bsr restore * Restore the drive
	2209	beq flopok * Jump if no error
	2210	*
	2211	flopin02: bra flopfail * Jump to error handler
	2212	*
	2213	.page
	2214	*
	2215	* floprd -- Read floppy
	2216	* ------ -----------
	2217	floprd: bsr change * Disk changed ?
	2218	moveq.l #ERR11,d0 * Set to "read error"
	2219	bsr floplock * Set parameters
	2220	*
	2221	floprd01: bsr select * Select drive and side
	2222	bsr go2track * Position on track
	2223	bne floprd02 * Try again on error
	2224	*
	2225	move.w #ERR01,deferr * Set default error
	2226	move.l edma(a5),a0 * Get final DMA address
	2227	move.l cdma(a5),a2 * Get first DMA address
	2228	move.l #$40000,d7 * Set timeout counter
	2229	move.b #FL_RM,DSKCMD(a6) * Start readng the disk
	2230	*
	2231	floprd03: btst #0,DSKCMD(a6) * Disk busy yet ?
	2232	bne floprd05 * Jump if so
	2233	*
	2234	subq.l #1,d7 * Decrement timeout counter
	2235	beq floprd04 * Jump if timed out
	2236	*
	2237	bra floprd03 * Go try for busy again
	2238	*
	2239	floprd05: move.l #$40000,d7 * Reset timeout counter
	2240	bra floprd09 * Go join main read loop
	2241	*
	2242	floprd07: subq.l #1,d7 * Decrement timeout counter
	2243	beq floprd04 * Jump if timed out
	2244	*
	2245	btst #0,DSKCMD(a6) * Done yet ?
	2246	beq floprd08 * Jump if so
	2247	*
	2248	floprd09: btst #1,DSKCMD(a6) * DRQ set ?
	2249	beq floprd07 * Jump if not
	2250	*
	2251	move.b DSKDAT(a6),(a2)+ * Read the byte into the buffer
	2252	cmp.l a0,a2 * Done reading ?
	2253	bne floprd07 * Jump if not
	2254	*
	2255	.page
	2256	*
	2257	floprd08: move.b DSKCMD(a6),d0 * Read final status into d0
	2258	and.b #$1C,d0 * Mask for error bits
	2259	beq flopok * Jump if no errors
	2260	*
	2261	bsr errbits * Determine error code
	2262	*
	2263	floprd02: cmp.w #1,retrycnt(a5) * Re-try ?
	2264	bne floprd06 * Jump if not
	2265	*
	2266	bsr reseek * Home and repeat the seek
	2267	*
	2268	floprd06: subq.w #1,retrycnt(a5) * Update re-try count
	2269	bpl floprd01 * Re-try if count still >0
	2270	*
	2271	bra flopfail * Failure
	2272	*
	2273	floprd04: move.w #ERR02,curerr(a5) * Set error code "not ready"
	2274	bsr rs1772 * Reset the WD1772
	2275	bra floprd02 * See if it can be retried
	2276	*
	2277	.page
	2278	*
	2279	* errbits -- Develop error code for floppy I/O error
	2280	* ------- ---------------------------------------
	2281	errbits: moveq.l #ERR13,d1 * Write protect ?
	2282	btst #6,d0 * ...
	2283	bne errbits1 * Jump if so
	2284	*
	2285	moveq.l #ERR08,d1 * Record not found ?
	2286	btst #4,d0 * ...
	2287	bne errbits1 * Jump if so
	2288	*
	2289	moveq.l #ERR04,d1 * CRC error ?
	2290	btst #3,d0 * ...
	2291	bne errbits1 * Jump if so
	2292	*
	2293	moveq.l #ERR12,d1 * Lost data ?
	2294	btst #2,d0 * ...
	2295	bne errbits1 * Jump if so
	2296	*
	2297	move.w deferr(a5),d1 * Use default error
	2298	*
	2299	errbits1: move.w d1,curerr(a5) * ... as curerr
	2300	rts * Return to caller
	2301	*
	2302	.page
	2303	*
	2304	* flopwr -- Floppy write
	2305	* ------ ------------
	2306	flopwr: bsr change * Check for disk change
	2307	moveq.l #ERR10,d0 * Set write error
	2308	bsr floplock * Set parameters
	2309	move.w csect(a5),d0 * Get sector number in d0
	2310	subq.w #1,d0 * ... -1
	2311	or.w ctrack(a5),d0 * OR with track number
	2312	or.w cside(a5),d0 * OR with side number
	2313	bne flopwr01 * Jump if not boot sector
	2314	*
	2315	moveq.l #2,d0 * Media change
	2316	bsr setdmode * Set to "unsure"
	2317	*
	2318	flopwr01: bsr select * Select drive and side
	2319	bsr go2track * Seek
	2320	bne flopwr06 * Re-try on error
	2321	*
	2322	flopwr02: move.w #ERR01,curerr(a5) * Set for default error
	2323	move.l cdma(a5),a2 * Get I/O address
	2324	move.l #$40000,d7 * Set timeout counter
	2325	move.w ctrack(a5),d0 * Get track number
	2326	cmpi.w #40,d0 * See if we need precomp
	2327	bcs flopwr10 * Jump if not
	2328	*
	2329	move.b #FL_WS,DSKCMD(a6) * Write with precomp
	2330	bra flopwr08 * Go join main write loop
	2331	*
	2332	flopwr10: move.b #FL_WS+FL_NC,DSKCMD(a6) * Write (no precomp)
	2333	*
	2334	.page
	2335	*
	2336	flopwr08: btst #0,DSKCMD(a6) * Busy yet ?
	2337	bne flopwr09 * Jump if so
	2338	*
	2339	subq.l #1,d7 * Decrement tiemout count
	2340	bne flopwr08 * Jump if not timed out
	2341	*
	2342	flopwr13: bsr rs1772 * Reset WD1772
	2343	bra flopwr05 * See if we can retry
	2344	*
	2345	flopwr11: btst #0,DSKCMD(a6) * Done ?
	2346	beq flopwr04 * Jump if so
	2347	*
	2348	flopwr09: btst #1,DSKCMD(a6) * DRQ set ?
	2349	bne flopwr12 * Jump if so
	2350	*
	2351	subq.l #1,d7 * Decrement timeout counter
	2352	beq flopwr13 * Jump if timed out
	2353	*
	2354	bra flopwr11 * Jump if not
	2355	*
	2356	flopwr12: move.b (a2)+,DSKDAT(a6) * Write byte to floppy
	2357	bra flopwr11 * Go get the next one
	2358	*
	2359	.page
	2360	*
	2361	flopwr04: move.b DSKCMD(a6),d0 * Get floppy status
	2362	bsr errbits * Set error code
	2363	btst #6,d0 * Write protect error ?
	2364	bne flopfail * Fail if so
	2365	*
	2366	and.b #$5C,d0 * Mask error bits
	2367	bne flopwr05 * Jump if an error occurred
	2368	*
	2369	addq.w #1,csect(a5) * Update sector number
	2370	add.l #512,cdma(a5) * Update DMA address
	2371	subq.w #1,ccount(a5) * Decrement sector count
	2372	beq flopok * Jump if zero -- done
	2373	*
	2374	bsr select1 * Set sector and DMA pointer
	2375	bra flopwr02 * Write next sector
	2376	*
	2377	flopwr05: cmp.w #1,retrycnt(a5) * Second re-try ?
	2378	bne flopwr07 * Jump if not
	2379	*
	2380	flopwr06: bsr reseek * Restore and re-seek
	2381	*
	2382	flopwr07: subq.w #1,retrycnt(a5) * Update re-try count
	2383	bpl flopwr01 * Re-try if still >0
	2384	*
	2385	bra flopfail * ... else fail
	2386	*
	2387	.page
	2388	*
	2389	* flopfmt -- Format a track on the floppy
	2390	* ------- ----------------------------
	2391	flopfmt: cmp.l #FMAGIC,22(a7) * Is the magic right ?
	2392	bne flopfail * Fail immediately if not
	2393	*
	2394	bsr change * Check for disk change
	2395	moveq.l #ERR01,d0 * Set default error number
	2396	bsr floplock * Set parameters
	2397	bsr select * Select drive and side
	2398	move.w 14(a7),spt(a5) * Set sectors per track,
	2399	move.w 20(a7),interlv(a5) * ... interleave,
	2400	move.w 26(a7),virgin(a5) * ... initial data,
	2401	moveq.l #2,d0 * Disk changed
	2402	bsr setdmode * ...
	2403	bsr hseek * Seek
	2404	bne flopfail * Fail if seek error occurs
	2405	*
	2406	move.w ctrack(a5),0(a1) * Current track to DSB
	2407	move.w #ERR01,curerr(a5) * Default to curerr
	2408	bsr fmtrack * Format the track
	2409	bne flopfail * Fail if error occurs
	2410	*
	2411	move.w spt(a5),ccount(a5) * Use spt as ccount
	2412	move.w #1,csect(a5) * Start with sector 1
	2413	bsr verify1 * Verify the sector
	2414	move.l cdma(a5),a2 * Get bad sector list
	2415	tst.w (a2) * Any bad ones ?
	2416	beq flopok * Jump if not
	2417	*
	2418	move.w #ERR16,curerr(a5) * ERROR -- "bad sectors"
	2419	bra flopfail
	2420	*
	2421	.page
	2422	*
	2423	* fmtrack -- Do the dirty work of formatting a track
	2424	* ------- ---------------------------------------
	2425	fmtrack: move.w #ERR10,deferr(a5) * Set default error number
	2426	move.w #1,d3 * Start with sector 1
	2427	move.l cdma(a5),a2 * Get track buffer address
	2428	move.w #60-1,d1 * Set count = 60
	2429	move.b #$4E,d0 * Write $4E as initial gap
	2430	bsr wmult * ...
	2431	*
	2432	fmtrak01: move.w d3,d4 * Save sector number in d4
	2433	*
	2434	fmtrak02: move.w #12-1,d1 * Set count = 12
	2435	clr.b d0 * Write $00 as sync
	2436	bsr wmult * ...
	2437	move.w #3-1,d1 * Set count = 3
	2438	move.b #$F5,d0 * Write $F5's
	2439	bsr wmult * ...
	2440	move.b #$FE,(a2)+ * Write $FE (address mark)
	2441	move.b ctrack+1,(a2)+ * Write track #
	2442	move.b cside+1,(a2)+ * Write side #
	2443	move.b d4,(a2)+ * Write sector #
	2444	move.b #2,(a2)+ * Write sector size code
	2445	move.b #$F7,(a2)+ * Write checksum code
	2446	move.w #22-1,d1 * Set count = 22
	2447	move.b #$4E,d0 * Write gap
	2448	bsr wmult * ...
	2449	move.w #12-1,d1 * Set count = 12
	2450	clr.b d0 * Write $00 as sync
	2451	bsr wmult * ...
	2452	move.w #3-1,d1 * Set count = 3
	2453	move.b #$F5,d0 * Write $F5's
	2454	bsr wmult * ...
	2455	move.b #$FB,(a2)+ * Write DAM
	2456	move.w #256-1,d1 * Set count = 256 words
	2457	*
	2458	.page
	2459	*
	2460	fmtrak03: move.b virgin(a5),(a2)+ * Write virgin data in buffer
	2461	move.b virgin+1(a5),(a2)+ * ...
	2462	dbf d1,fmtrak03 * ...
	2463	*
	2464	move.b #$F7,(a2)+ * Write CRC code
	2465	move.w #40-1,d1 * Set count = 40
	2466	move.b #$4E,d0 * Write gap
	2467	bsr wmult * ...
	2468	add.w interlv(a5),d4 * Add interleave to sector #
	2469	cmp.w spt(a5),d4 * Check against spt
	2470	ble fmtrak02 * Jump if not >
	2471	*
	2472	addq.w #1,d3 * Starting sector +1
	2473	cmp.w interlv(a5),d3
	2474	ble fmtrak01
	2475	*
	2476	move.w #1401-1,d1 * Set count = 1401
	2477	move.b #$4E,d0 * Write final gap
	2478	bsr wmult * ...
	2479	move.l cdma(a5),a2 * Get buffer address
	2480	move.l #$40000,d7 * Set timeout count
	2481	move.w ctrack(a5),d0 * Get track number
	2482	cmpi.w #40,d0 * Do we need precomp ?
	2483	bcs fmtrak08 * Jump if not
	2484	*
	2485	move.b #FL_WT,DSKCMD(a6) * Start format with precomp
	2486	bra fmtrak07 * Go join main format loop
	2487	*
	2488	fmtrak08: move.b #FL_WT+FL_NC,DSKCMD(a6) * Start format without precomp
	2489	*
	2490	.page
	2491	*
	2492	fmtrak07: btst #0,DSKCMD(a6) * Busy yet ?
	2493	bne fmtrak09 * Jump if so
	2494	*
	2495	fmtrak04: subq.l #1,d7 * Decrement timeout counter
	2496	bne fmtrak07 * Jump if not timed out
	2497	*
	2498	fmtrak05: bsr rs1772 * Reset WD1772
	2499	moveq.l #1,d7 * Set error flag
	2500	rts * Return to caller
	2501	*
	2502	fmtrak11: btst #0,DSKCMD(a6) * Done ?
	2503	beq fmtrak06 * Jump if so
	2504	*
	2505	fmtrak09: btst #1,DSKCMD(a6) * DRQ set ?
	2506	bne fmtrak10 * Jump if so
	2507	*
	2508	subq.l #1,d7 * Decrement timeout coutner
	2509	beq fmtrak05 * Jump if timed out
	2510	*
	2511	bra fmtrak11 * Go check again
	2512	*
	2513	fmtrak10: move.b (a2)+,DSKDAT(a6) * Write a byte of format
	2514	bra fmtrak11 * Go wait for DRQ
	2515	*
	2516	fmtrak06: move.b DSKCMD(a6),d0 * Get final status
	2517	bsr errbits * Set possible error code
	2518	andi.b #$44,d0 * Check error bits
	2519	rts * Return to caller with status
	2520	*
	2521	* wmult -- write multiple bytes into the track buffer
	2522	* ----- ------------------------------------------
	2523	wmult: move.b d0,(a2)+ * Move a byte into the buffer
	2524	dbf d1,wmult * Loop until we're done
	2525	*
	2526	rts * Return to caller
	2527	*
	2528	.page
	2529	*
	2530	* flopver -- verify sector(s) on a floppy
	2531	* ------- ----------------------------
	2532	flopver: bsr change * Check for disk change
	2533	moveq.l #ERR11,d0 * Set default to "read error"
	2534	bsr floplock * Set parameters
	2535	bsr select * Select drive and side
	2536	bsr go2track * Seek
	2537	bne flopfail * Jump if seek error
	2538	*
	2539	bsr verify1 * Verify the data
	2540	bra flopok * Done
	2541	*
	2542	* verify1 -- Verify the data for a sector
	2543	* ------- ----------------------------
	2544	verify1: move.w #ERR11,deferr(a5) * Set default = "read error"
	2545	move.l cdma(a5),a2 * Pointer for bad sector list
	2546	add.l #512,cdma(a5) * Update by length of a sector
	2547	*
	2548	verify01: move.w #2,retrycnt(a5) * Set retrycnt for 2 attempts
	2549	move.w csect(a5),d7 * Get sector nubmer
	2550	move.b d7,DSKSEC(a6) * Send to WD1772
	2551	*
	2552	verify02: moveq.l #0,d6 * Clear bad compare flag
	2553	move.l cdma(a5),a0 * Get compare address
	2554	move.l #$40000,d7 * Set timeout counter
	2555	move.b #FL_RS,DSKCMD(a6) * Start the read
	2556	*
	2557	verify08: btst #0,DSKCMD(a6) * Busy yet ?
	2558	bne verify09 * Jump if so
	2559	*
	2560	subq.l #1,d7 * Decrement timeout counter
	2561	beq verify13 * Jump if timed out
	2562	*
	2563	bra verify08 * Wait for busy some more
	2564	*
	2565	verify09: move.l #$40000,d7 * Reset timeout counter
	2566	bra verify11 * Go join main compare loop
	2567	*
	2568	verify10: subq.l #1,d7 * Decrement timeout counter
	2569	beq verify13 * Jump if timed out
	2570	*
	2571	btst #0,DSKCMD(a6) * Done yet ?
	2572	beq verify12 * Jump if so
	2573	*
	2574	.page
	2575	*
	2576	verify11: btst #1,DSKCMD(a6) * DRQ set ?
	2577	beq verify10 * Jump if not
	2578	*
	2579	move.b DSKDAT(a6),d0 * Read data
	2580	bra verify10 * Continue reading
	2581	*
	2582	verify12: move.b DSKCMD(a6),d0 * Get final status
	2583	bsr errbits * Determine error code
	2584	and.b #$1C,d0 * Mask RNF, CRC, LOST
	2585	bne verify06 * Jump to re-try if any set
	2586	*
	2587	verify05: addq.w #1,csect(a5) * Update sector number
	2588	subq.w #1,ccount(a5) * Update sector count
	2589	bne verify01 * Jump if more to do
	2590	*
	2591	sub.l #512,cdma(a5) * Reset DMA pointer
	2592	clr.w (a2) * Set NIL in bad sector list
	2593	rts * Return to caller
	2594	*
	2595	verify06: cmp.w #1,retrycnt(a5) * Is it the 2nd attempt ?
	2596	bne verify07 * Jump if not
	2597	*
	2598	bsr reseek * Restore and re-seek
	2599	*
	2600	verify07: subq.w #1,retrycnt(a5) * Decrement retry count
	2601	bpl verify02 * Re-try if still positive
	2602	*
	2603	move.w csect(a5),(a2)+ * Add to bad sector list
	2604	bra verify05 * Go do next sector
	2605	*
	2606	verify13: move.w #ERR02,curerr(a5) * Set timeout error code
	2607	bsr rs1772 * Reset WD1772
	2608	bra verify06 * See if we can retry it
	2609	*
	2610	.page
	2611	*
	2612	* flopvbl -- Floppy VBL timer interrupt handling
	2613	* ------- -----------------------------------
	2614	flopvbl: movem.l d0-d1/a0-a1/a5-a6,-(a7) * Save registers
	2615	sub.l a5,a5 * Clear a5 for use as RAM base
	2616	lea FLOPPY,a6 * Base of floppy regs
	2617	st motoron(a5) * Set motoron flag
	2618	move.l frclock(a5),d0 * Get interrupt count
	2619	move.b d0,d1 * ...
	2620	and.b #7,d1 * ... MOD 8
	2621	bne flopvb02 * Jump if not 8th int
	2622	*
	2623	move.w sr,-(a7) * Save interrupt level
	2624	ori.w #IPL7,sr * Mask off interrupts
	2625	clr.w deslflag(a5) * Clear deselect flag
	2626	move.b mc1iorec+cfr1,d0 * Get port status
	2627	ori.b #1,d0 * Set drive select bit
	2628	move.b d0,MC1ACIA+ACIA_CFR * Send drive select to port
	2629	move.b d0,mc1iorec+cfr1 * Store updated port status
	2630	move.w (a7)+,sr * Restore interrupt level
	2631	lea wpstatus(a5),a0 * Point at wpstatus for drive
	2632	lea dsb0(a5),a1 * Point at dsb0
	2633	move.b DSKCMD(a6),d0 * Read WD1772 status
	2634	btst #6,d0 * Test write protect bit
	2635	sne (a0) * ... and save
	2636	*
	2637	.page
	2638	*
	2639	flopvb02: move.w wpstatus(a5),d0 * Get wpstatus of drive A
	2640	or.w d0,wplatch(a5) * OR into wplatch
	2641	tst.w deslflag(a5) * Floppies already deselected ?
	2642	bne flopvb03 * Jump if so
	2643	*
	2644	move.b DSKCMD(a6),d0 * Read WD1772 status
	2645	btst #7,d0 * Motor-on bit set ?
	2646	bne flopvb04 * Don't de-select if it is
	2647	*
	2648	move.w sr,-(a7) * Save sr
	2649	ori.w #IPL7,sr * Disable interrupts
	2650	move.b mc1iorec+cfr1,d0 * Get cfr1 image
	2651	bclr #0,d0 * Clear d0 (drive select)
	2652	move.b d0,mc1iorec+cfr1 * Save new value
	2653	move.b d0,MC1ACIA+ACIA_CFR * Send to hardware
	2654	move.w (a7)+,sr * Restore sr (enable ints)
	2655	move.w #1,deslflag(a5) * Set the deselect flag
	2656	*
	2657	flopvb03: clr.w motoron(a5) * Clear motoron flag
	2658	*
	2659	flopvb04: movem.l (a7)+,d0-d1/a0-a1/a5-a6 * Restore registers
	2660	rts * Return to caller
	2661	*
	2662	.page
	2663	*
	2664	* floplock -- Setup floppy parameters
	2665	* -------- -----------------------
	2666	floplock: movem.l d3-d7/a3-a6,flpregs * Save registers
	2667	move.w sr,flpsrsv * Save sr
	2668	ori.w #IPL7,sr * Disable ints
	2669	sub.l a5,a5 * Clear a5
	2670	lea FLOPPY,a6 * Base of floppy registers
	2671	st motoron(a5) * Set motoron flag
	2672	move.w d0,deferr(a5) * Set default error code
	2673	move.w d0,curerr(a5) * ... current error code
	2674	move.w #1,flock(a5) * Disable flopvbl routine
	2675	move.l 8(a7),cdma(a5) * Set cdma
	2676	move.w 16(a7),cdev(a5) * ... cdev
	2677	move.w 18(a7),csect(a5) * ... csect
	2678	move.w 20(a7),ctrack(a5) * ... ctrack
	2679	move.w 22(a7),cside(a5) * ... cside
	2680	move.w 24(a7),ccount(a5) * ... ccount
	2681	move.w #2,retrycnt(a5) * ... retrycnt
	2682	lea dsb0(a5),a1 * Address of dsb0
	2683	tst.w cdev(a5) * Drive A ?
	2684	beq floplk01 * Jump if so
	2685	*
	2686	lea dsb1(a5),a1 * Drive B, use dsb1
	2687	*
	2688	floplk01: moveq.l #0,d7 * Clear out d7
	2689	move.w ccount(a5),d7 * Get ccount
	2690	lsl.w #8,d7 * ... * sector length (512)
	2691	lsl.w #1,d7 * ...
	2692	move.l cdma(a5),a0 * Get DMA start address
	2693	add.l d7,a0 * Add length of sectors
	2694	move.l a0,edma(a5) * Set edma (end DMA address)
	2695	tst.w 0(a1) * Check current track
	2696	bpl floplk03 * Jump if >= 0
	2697	*
	2698	bsr select * Select the drive
	2699	clr.w 0(a1) * Set current track to 0
	2700	bsr restore * Restore drive to track 0
	2701	beq floplk03 * Jump if OK
	2702	*
	2703	moveq.l #10,d7 * Seek out to track 10
	2704	bsr hseek1 * ...
	2705	bne floplk02 * Jump if an error occurred
	2706	*
	2707	bsr restore * Try the restore again
	2708	beq floplk03 * Jump if OK
	2709	*
	2710	floplk02: move.w #$FF00,0(a1) * Recalibrate error
	2711	*
	2712	floplk03: rts * Return to caller
	2713	*
	2714	.page
	2715	*
	2716	* flopfail -- Floppy I/O failure exit
	2717	* -------- -----------------------
	2718	flopfail: moveq.l #1,d0 * Set media change to "unsure"
	2719	bsr setdmode * ...
	2720	move.w curerr(a5),d0 * Get curerr
	2721	ext.l d0 * ...
	2722	bra flopok1 * Go set end status
	2723	*
	2724	* flopok -- Floppy I/O success exit
	2725	* ------ -----------------------
	2726	flopok: clr.l d0 * Set error code = 0 (no error)
	2727	*
	2728	flopok1: move.l d0,-(a7) * Push code onto stack
	2729	move.w 0(a1),d7 * Get track number
	2730	move.b d7,DSKDAT(a6) * Send to WD1772
	2731	move.w #FL_SK,d6 * Seek command to d6
	2732	bsr flopcmds * Send command
	2733	move.w cdev(a5),d0 * Get drive number
	2734	lsl.w #2,d0 * Use as index
	2735	lea acctim(a5),a0 * ... into acctim
	2736	move.l _hz_200(a5),0(a0,d0) * Set last access time
	2737	cmp.w #1,nflops(a5)
	2738	bne flopok01
	2739	*
	2740	move.l _hz_200(a5),4(a0) * Time for other drive
	2741	*
	2742	flopok01: move.w flpsrsv,sr * Restore sr (enable ints)
	2743	move.l (a7)+,d0 * Restore error number to d0
	2744	movem.l flpregs,d3-d7/a3-a6 * Restore registers
	2745	clr.w flock * Release flopvbl routine
	2746	rts * Return to caller
	2747	*
	2748	.page
	2749	*
	2750	* hseek -- seek to track in ctrack
	2751	* ----- -----------------------
	2752	hseek: move.w ctrack,d7 * Get ctrack
	2753	*
	2754	* hseek1 -- seek to track in d7
	2755	* ------ -------------------
	2756	hseek1: move.w #ERR10,curerr * Set curerr = "seek error"
	2757	move.b d7,DSKDAT(a6) * Send track number to WD1772
	2758	move.w #FL_SK,d6 * Seek command
	2759	bra flopcmds * Go send command to WD1772
	2760	*
	2761	* reseek -- Restore, then re-seek
	2762	* ------ ---------------------
	2763	reseek: move.w #ERR10,curerr * Set curerr = "seek error"
	2764	bsr restore * Restore
	2765	bne reseek01 * Jump if error occurred
	2766	*
	2767	clr.w 0(a1) * Clear current track to 0
	2768	move.b #0,DSKTRK(a6) * Send track to WD1772
	2769	move.b #5,DSKDAT(a6) * Setup to seek to track 5
	2770	move.w #FL_SK,d6 * Seek command
	2771	bsr flopcmds * Seek
	2772	bne reseek01 * Jump if error
	2773	*
	2774	move.w #5,0(a1) * Update current track = 5
	2775	*
	2776	* go2track -- seek with verify
	2777	* -------- ----------------
	2778	go2track: move.w #ERR10,curerr(a5) * Set curerr = "seek error"
	2779	move.w ctrack(a5),d7 * Put track # in d7
	2780	move.b d7,DSKDAT(a6) * Send track to WD1772
	2781	moveq.l #FL_SV,d6 * Seek/verify command
	2782	bsr flopcmds * Send command to floppy
	2783	bne reseek01 * Jump if error occurred
	2784	*
	2785	move.w ctrack(a5),0(a1) * Update track number in dsb
	2786	and.b #$18,d7 * Test for RNF, CRC, LOST
	2787	*
	2788	reseek01: rts * Return to caller
	2789	*
	2790	.page
	2791	*
	2792	* restore -- Restore to track 0
	2793	* ------- ------------------
	2794	restore: clr.w d6 * Restore command
	2795	bsr flopcmds * Send to WD1772
	2796	bne restor01 * Jump if an error occurred
	2797	*
	2798	btst #2,d7 * Check track 0 bit
	2799	eori #0004,sr * Invert Z flag in 680000 sr
	2800	bne restor01 * Jump if not track 0
	2801	*
	2802	clr.w 0(a1) * Set track = 0 in dsb
	2803	*
	2804	restor01: rts * Return to caller
	2805	*
	2806	* flopcmds -- Send command to WD1772 floppy controller
	2807	* -------- ----------------------------------------
	2808	flopcmds: move.w 2(a1),d0 * Get seek rate from dsb
	2809	and.b #$3,d0 * ...
	2810	or.b d0,d6 * OR into command word
	2811	move.l #$40000,d7 * Set timeout counter
	2812	btst #7,DSKCMD(a6) * Motor on ?
	2813	bne flopcm01 * Jump if so
	2814	*
	2815	move.l #$60000,d7 * Set longer timeout count
	2816	*
	2817	flopcm01: move.b d6,DSKCMD(a6) * Write command from d6
	2818	*
	2819	move.l #$1000,d0 * Set initial busy timeout in d0
	2820	*
	2821	flopcm04: btst #0,DSKCMD(a6) * Controller busy yet ?
	2822	bne flopcm02 * Jump if so
	2823	*
	2824	subq.l #1,d0 * Decrement timeout counter
	2825	beq flopcm03 * Jump if timed out
	2826	*
	2827	bra flopcm04 * Wait for busy some more
	2828	*
	2829	flopcm02: subq.l #1,d7 * Decrement timeout counter
	2830	beq flopcm03 * Jump if timed out
	2831	*
	2832	btst #0,DSKCMD(a6) * WD1772 done ?
	2833	bne flopcm02 * Jump if not
	2834	*
	2835	clr.l d7 * Clear out upper bits of d7
	2836	move.b DSKCMD(a6),d7 * Read status into LS byte of d7
	2837	clr.l d6 * Clear error flag in d6
	2838	rts * Return to caller
	2839	*
	2840	flopcm03: bsr rs1772 * Reset WD1772 (end transfer)
	2841	moveq.l #1,d6 * Set error flag in d6
	2842	rts * Return to caller
	2843	*
	2844	.page
	2845	*
	2846	* rs1772 -- Reset WD1772 floppy controller
	2847	* ------ ------------------------------
	2848	rs1772: move.b #FL_FR,DSKCMD(a6) * Send reset to WD1772
	2849	move.w #15,d7 * Set delay count
	2850	*
	2851	rs1772a: dbf d7,rs1772a * Delay a while
	2852	rts * Return to caller
	2853	*
	2854	* select -- Select drive and side
	2855	* ------ ----------------------
	2856	select: move.w sr,-(a7) * Save sr on stack
	2857	ori.w #IPL7,sr * Disable interrupts
	2858	clr.w deslflag(a5) * Clear deselect flag
	2859	move.b mc1iorec+cfr1,d0 * Get current MC1 cfr1 image
	2860	ori.b #1,d0 * Select drive (we only have 1)
	2861	move.b d0,mc1iorec+cfr1 * Store updated image
	2862	move.b d0,MC1ACIA+ACIA_CFR * Send it to the MC1 ACIA
	2863	move.w cside(a5),d0 * Get side number (LS bit)
	2864	and.w #1,d0 * Mask off garbage bits
	2865	andi.b #$FE,mc2iorec+cfr1 * Mask off D0 in MC2 cfr1 image
	2866	or.b mc2iorec+cfr1,d0 * OR side with mc2iorec cfr1
	2867	move.b d0,mc2iorec+cfr1 * Store updated cfr1 image
	2868	move.b d0,MC2ACIA+ACIA_CFR * Send it to the MC2 ACIA
	2869	move.w (a7)+,sr * Restore interrupts
	2870	move.w 0(a1),d7 * Get track from dsb
	2871	move.b d7,DSKTRK(a6) * Send it to the WD1772
	2872	clr.b tmpdma(a5) * Clear bits 31..24 of tmpdma
	2873	*
	2874	select1: move.w csect(a5),d7 * Get sector number
	2875	move.b d7,DSKSEC(a6) * Send it to the WD1772
	2876	move.l cdma(a5),a0 * Setup transfer address in a0
	2877	rts * Return to caller
	2878	*
	2879	.page
	2880	*
	2881	* change -- Check for disk change status
	2882	* ------ ----------------------------
	2883	change: cmp.w #1,nflops * Check # of floppies
	2884	bne change02
	2885	*
	2886	move.w 16(a7),d0 * Drive number to d0
	2887	cmp.w disknum,d0
	2888	beq change01 * Jump if =
	2889	*
	2890	move.w d0,-(a7) * Stack drive number
	2891	move.w #ERR17,-(a7) * Stack error code
	2892	bsr criter * Do critical error routine
	2893	addq.w #4,a7 * Cleanup stack
	2894	move.w #$FFFF,wplatch * Status for drives = "unsure"
	2895	move.w 16(a7),disknum * Save disk number
	2896	*
	2897	change01: clr.w 16(a7) * Clear disk number
	2898	*
	2899	change02: rts * Return to caller
	2900	*
	2901	* setdmode -- Set drive change mode
	2902	* -------- ---------------------
	2903	setdmode: lea dskmode,a0 * Point at disk mode table
	2904	move.b d0,-(a7) * Save mode on stack
	2905	move.w cdev(a5),d0 * Get drive number
	2906	move.b (a7)+,0(a0,d0) * Set drive mode / cleanup stack
	2907	rts * Return to caller
	2908	*
	2909	.page
	2910	*
	2911	* bootload -- Load boot sector
	2912	* -------- ----------------
	2913	bootload: link a6,#0 * Link stack frames
	2914	movem.l d6-d7,-(a7) * Save registers
	2915	jsr _hdvini * Init drive
	2916	tst.w nflops * See if any connected
	2917	beq bootld01 * Jump if drive there
	2918	*
	2919	moveq.l #1,d0 * "couldn't load"
	2920	bra bootld02
	2921	*
	2922	bootld01: moveq.l #2,d0 * "no drive connected"
	2923	*
	2924	bootld02: move.w d0,d7 * Save possible error in d7
	2925	tst.w nflops
	2926	beq bootld04
	2927	*
	2928	cmp.w #2,bootdev
	2929	bge bootld04
	2930	*
	2931	move.w #1,(a7) * Sector count = 1,
	2932	clr.w -(a7) * ... side = 0,
	2933	clr.w -(a7) * ... track = 0,
	2934	move.w #1,-(a7) * ... sector = 1,
	2935	move.w bootdev,-(a7) * ... drive = bootdev,
	2936	clr.l -(a7) * ... filler,
	2937	move.l #buffer,-(a7) * ... buffer address
	2938	jsr floprd * Read the sector
	2939	add.l #16,a7 * Cleanup stack
	2940	tst.l d0 * Error ?
	2941	bne bootld03 * Jump if not
	2942	*
	2943	clr.w d7
	2944	bra bootld04
	2945	*
	2946	bootld03: tst.b wpstatus
	2947	bne bootld04
	2948	*
	2949	moveq.l #3,d0 * "unreadable"
	2950	bra bootld07
	2951	*
	2952	bootld04: tst.w d7
	2953	beq bootld05
	2954	*
	2955	move.w d7,d0 * Get old error code
	2956	bra bootld07
	2957	*
	2958	.page
	2959	*
	2960	bootld05: move.w #256,(a7) * Set count for 256 words
	2961	move.l #buffer,-(a7) * Point at buffer
	2962	bsr chksum * Calculate checksum
	2963	addq.l #4,a7 * Cleanup stack
	2964	cmp.w #$1234,d0 * Boot sector checksum ?
	2965	bne bootld06 * Jump if not
	2966	*
	2967	clr.w d0 * Set flag for OK
	2968	move.w bootdev,booted * Save last boot device
	2969	bra bootld07
	2970	*
	2971	bootld06: moveq.l #4,d0 * "not valid boot sector"
	2972	*
	2973	bootld07: tst.l (a7)+
	2974	movem.l (a7)+,d7 * Restore registers
	2975	unlk a6
	2976	rts * Return to caller
	2977	*
	2978	.page
	2979	*
	2980	* chksum -- caluculate checksum
	2981	* ------ -------------------
	2982	chksum: link a6,#0
	2983	movem.l d6-d7,-(a7) * Preserve registers
	2984	clr.w d7 * Clear sum
	2985	bra chksum02 * Jump into loop
	2986	*
	2987	chksum01: move.l 8(a6),a0 * Get buffer address
	2988	move.w (a0),d0 * Get word
	2989	add.w d0,d7 * Add to checksum in d7
	2990	addq.l #2,8(a6) * Update buffer address
	2991	*
	2992	chksum02: move.w 12(a6),d0 * Get word count
	2993	subq.w #1,12(a6) * Decrement it
	2994	tst.w d0 * Done ?
	2995	bne chksum01 * Loop if not
	2996	*
	2997	move.w d7,d0 * Put result in d0
	2998	tst.l (a7)+
	2999	movem.l (a7)+,d7 * Restore registers
	3000	unlk a6
	3001	rts * Return to caller
	3002	*
	3003	.page
	3004	*
	3005	* mult32 -- 32 bit signed multiply
	3006	* ------ ----------------------
	3007	mult32: link a6,#-4
	3008	clr.w d2
	3009	tst.l 8(a6)
	3010	bge mult32a
	3011	*
	3012	neg.l 8(a6)
	3013	addq.w #1,d2
	3014	*
	3015	mult32a: tst.l 12(a6)
	3016	bge mult32b
	3017	*
	3018	neg.l 12(a6)
	3019	addq.w #1,d2
	3020	*
	3021	mult32b: move.w 10(a6),d0
	3022	mulu 14(a6),d0
	3023	move.l d0,-4(a6)
	3024	move.w 8(a6),d0
	3025	mulu 14(a6),d0
	3026	move.w 12(a6),d1
	3027	mulu 10(a6),d1
	3028	add.w d1,d0
	3029	add.w -4(a6),d0
	3030	move.w d0,-4(a6)
	3031	move.l -4(a6),d0
	3032	btst #0,d2
	3033	beq mult32c
	3034	*
	3035	neg.l d0
	3036	*
	3037	mult32c: unlk a6
	3038	rts
	3039	*
	3040	.page
	3041	*
	3042	* rand -- Generate a random number
	3043	* ---- ------------------------
	3044	rand: link a6,#-4 * Reserve stack for temps
	3045	tst.l rseed * See if the seed is zero
	3046	bne rand01 * Jump if not
	3047	*
	3048	move.l _hz_200,d0 * Pick up the 200 Hz clock
	3049	moveq.l #16,d1 * Shift it left
	3050	asl.l d1,d0 * ...
	3051	or.l _hz_200,d0 * OR in current 200 Hz clock
	3052	move.l d0,rseed * Use that as the seed
	3053	*
	3054	rand01: move.l #$BB40E62D,-(a7) * Put PI on the stack
	3055	move.l rseed,-(a7) * ... and rseed, too
	3056	bsr mult32 * Multiply them
	3057	addq.l #8,a7 * Cleanup stack
	3058	addq.l #1,d0 * Add 1 to the result
	3059	move.l d0,rseed * Save as new seed
	3060	move.l rseed,d0
	3061	asr.l #8,d0 * Make it a 24 bit number
	3062	and.l #$FFFFFF,d0 * ...
	3063	unlk a6 * Release stack
	3064	rts * Return to caller
	3065	*
	3066	.page
	3067	*
	3068	* protobt -- Generate a prototype boot sector
	3069	* ------- --------------------------------
	3070	protobt: link a6,#-6
	3071	movem.l d5-d7/a5,-(a7) * Save registers
	3072	tst.w 18(a6) * Test execflg
	3073	bge protbt03 * Jump if set
	3074	*
	3075	move.w #256,(a7) * Count = 256 words
	3076	move.l 8(a6),-(a7) * Address of buffer
	3077	bsr chksum * Calculate checksum
	3078	addq.l #4,a7 * Cleanup stack
	3079	cmp.w #$1234,d0 * Boot checksum ?
	3080	beq protbt01 * Jump if so
	3081	*
	3082	clr.w d0 * Not executable
	3083	bra protbt02
	3084	*
	3085	protbt01: moveq.l #1,d0 * Executable
	3086	*
	3087	protbt02: move.w d0,18(a6) * Set execflg
	3088	*
	3089	protbt03: tst.l 12(a6) * Serial number ?
	3090	blt protbt07 * Jump if not to be changed
	3091	*
	3092	move.l 12(a6),d0 * Get it into d0
	3093	cmp.l #$FFFFFF,d0 * > $FFFFFF
	3094	ble protbt04 * Jump if not
	3095	*
	3096	bsr rand * Generate a random number
	3097	move.l d0,12(a6) * Save as s/n
	3098	*
	3099	protbt04: clr.w d7 * Clear counter
	3100	bra protbt06 * Enter move loop
	3101	*
	3102	.page
	3103	*
	3104	protbt05: move.l 12(a6),d0 * Get s/n
	3105	and.l #$FF,d0 * Isolate low 8 bits
	3106	move.w d7,a1 * Point to next byte
	3107	add.l 8(a6),a1 * ...
	3108	move.b d0,8(a1) * Write byte in buffer
	3109	move.l 12(a6),d0 * Get s/n
	3110	asr.l #8,d0 * Shift right 8 bits
	3111	move.l d0,12(a6) * Save shifted value
	3112	addq.w #1,d7 * Update counter
	3113	*
	3114	protbt06: cmp.w #3,d7 * See if we're done
	3115	blt protbt05 * Loop if not
	3116	*
	3117	protbt07: tst.w 16(a6) * Diskette size ?
	3118	blt protbt10 * Jump if not to be changed
	3119	*
	3120	move.w 16(a6),d6 * Get diskette size
	3121	muls.w #19,d6 * ... times 19 as pointer
	3122	clr.w d7 * Clear counter
	3123	bra protbt09 * Go move in BPB
	3124	*
	3125	protbt08: move.w d7,a0 * Get counter
	3126	add.l 8(a6),a0 * Add base of buffer
	3127	move.w d6,a1 * Get BPB pointer
	3128	add.l #pbpbtab,a1 * Add base of prototype BPB's
	3129	move.b (a1),11(a0) * Copy BPB data
	3130	addq.w #1,d6 * Update pointer
	3131	addq.w #1,d7 * Update counter
	3132	*
	3133	protbt09: cmp.w #19,d7 * Done ?
	3134	blt protbt08 * Loop if not
	3135	*
	3136	protbt10: clr.w -6(a6)
	3137	move.l 8(a6),-4(a6)
	3138	bra protbt12
	3139	*
	3140	.page
	3141	*
	3142	protbt11: move.l -4(a6),a0 * Get buffer pointer
	3143	move.w (a0),d0 * Get word from buffer
	3144	add.w d0,-6(a6) * Sum for checksum
	3145	addq.l #2,-4(a6) * Point at next word
	3146	*
	3147	protbt12: move.l 8(a6),d0 * Get buffer address
	3148	add.l #$1FE,d0 * Plus sector length
	3149	cmp.l -4(a6),d0 * Done ?
	3150	bhi protbt11 * Loop if not
	3151	*
	3152	move.w #$1234,d0 * Checksum for boot sector
	3153	sub.w -6(a6),d0 * Subtract checksum for buffer
	3154	move.l -4(a6),a1
	3155	move.w d0,(a1) * Store checksum in buffer
	3156	tst.w 18(a6) * Check execflg
	3157	bne protbt13 * Boot sector to be executable ?
	3158	*
	3159	move.l -4(a6),a0 * Mung checksum so it's not
	3160	addq.w #1,(a0)
	3161	*
	3162	protbt13: tst.l (a7)+
	3163	movem.l (a7)+,d6-d7/a5 * Restore registers
	3164	unlk a6 * Release stack
	3165	rts * Return to caller
	3166	*
	3167	.endc
	3168	*
	3169	* criter -- Critical error handler
	3170	* ------ ----------------------
	3171	criter: move.l critvec,-(a7) * Put error vector on stack
	3172	moveq.l #-1,d0 * Set default error return
	3173	rts * "Return" to handler
	3174	*
	3175	.page
	3176	*
	3177	.ifne BUCHLA
	3178	*
	3179	* api_int -- Analog processor interrupt handler
	3180	* ------- ----------------------------------
	3181	api_int: movem.l d0-d1/a0-a1,-(a7) * Save registers
	3182	clr.l d0 * Read input port
	3183	move.b ANALOG,d0 * ... into d0[7..0]
	3184	move.b d0,api_inp * ... and api_inp
	3185	btst #7,d0 * Check for signal number flag
	3186	bne api_s0a * Jump if signal number read
	3187	*
	3188	lea api_tv,a0 * Get api_tv base in a0
	3189	clr.w d1 * Get api_sv in d1
	3190	move.b api_sv,d1 * ...
	3191	cmpi.b #6,d1 * Check range
	3192	bgt api_sve * Jump if out of range
	3193	*
	3194	lsl.w #2,d1 * Develop jump address
	3195	move.l 0(a0,d1.W),a1 * ... from api_tv in a1
	3196	jmp (a1) * Jump to state handler
	3197	*
	3198	api_s0: btst #7,d0 * Check for signal number flag
	3199	beq api_ret * Jump if not signal number
	3200	*
	3201	api_s0a: clr.b api_val * Clear value byte
	3202	andi.b #$7F,d0 * Mask off signal number flag
	3203	cmpi.b #82,d0 * See if it's in range
	3204	bgt api_err * Jump if out of range (GT 82)
	3205	*
	3206	move.b d0,api_sig * Store signal number
	3207	beq api_pub * Jump if it was "all off"
	3208	*
	3209	lea api_tab,a0 * Get sv table base
	3210	move.b 0(a0,d0.W),api_sv * Set sv for next time
	3211	*
	3212	api_ret: movem.l (a7)+,d0-d1/a0-a1 * Restore registers
	3213	rte * Return to interrupted code
	3214	*
	3215	api_err: move.b d0,api_bug * Catch the bug
	3216	clr.b api_sv * Force state zero
	3217	bra api_ret * Go back to interrupted code
	3218	*
	3219	api_sve: move.b d1,api_svb * Catch the bug
	3220	clr.b api_sv * Force state zero
	3221	bra api_ret * Go back to interrupted code
	3222	*
	3223	.page
	3224	api_s1: btst #0,d0 * See if it takes a value
	3225	beq api_s1a * Jump if not
	3226	*
	3227	move.b #2,api_sv * Set sv for state 2
	3228	bra api_ret * Go return from interrupt
	3229	*
	3230	api_s1a: clr.b api_val * Clear value byte
	3231	bra api_pub * Go output to fifo
	3232	*
	3233	api_s2: ori.b #$80,d0 * Set status = 1
	3234	move.b d0,api_val * Set value byte
	3235	bra api_pub * Go output to fifo
	3236	*
	3237	api_s3: ror.b #1,d0 * Set status in value byte
	3238	andi.b #$80,d0 * ...
	3239	move.b d0,api_val * ...
	3240	move.b #4,api_sv * Set sv for state 4
	3241	bra api_ret * Go return from interrupt
	3242	*
	3243	api_s4: or.b d0,api_val * Set value byte
	3244	bra api_pub * Go output to fifo
	3245	*
	3246	api_s5: ror.b #1,d0 * Set status in value byte
	3247	andi.b #$80,d0 * ...
	3248	*
	3249	api_s6: move.b d0,api_val * Set value byte
	3250	*
	3251	api_pub: movea.l api_fi,a0 * Get fifo input pointer in a0
	3252	move.w api_sig,(a0)+ * Store new input
	3253	cmpa.l #api_fe,a0 * Wrap around ?
	3254	blt api_pb1 * Jump if not
	3255	*
	3256	movea.l #api_fum,a0 * Wrap input pointer to start
	3257	*
	3258	api_pb1: move.l a0,api_fi * Update input pointer
	3259	cmpa.l api_fo,a0 * Buffer full ?
	3260	bne api_pb3 * Jump if not
	3261	*
	3262	movea.l api_fo,a1 * Get fifo output pointer in a1
	3263	adda.l #2,a1 * Increment it
	3264	cmpa.l #api_fe,a1 * Wrap around ?
	3265	blt api_pb2 * Jump if not
	3266	*
	3267	movea.l #api_fum,a1 * Wrap output pointer to start
	3268	*
	3269	api_pb2: move.l a1,api_fo * Set new output pointer
	3270	*
	3271	api_pb3: clr.b api_sv * Set state to 0
	3272	bra api_ret * Return from interrupt
	3273	*
	3274	.page
	3275	*
	3276	* api_get -- Get analog input
	3277	* ------- ----------------
	3278	api_get: move.w sr,-(a7) * Save status register
	3279	ori.w #IPL3,sr * Disable ANALOG I/O interrupts
	3280	movea.l api_fo,a0 * Get fifo output pointer
	3281	cmpa.l api_fi,a0 * See if fifo is empty
	3282	bne api_g1 * Jump if not
	3283	*
	3284	moveq.l #-1,d0 * Set empty-fifo value
	3285	move.w (a7)+,sr * Restore interrupt mask
	3286	rts * Return to caller
	3287	*
	3288	api_g1: clr.l d0 * Get fifo value
	3289	move.w (a0)+,d0 * ...
	3290	cmpa.l #api_fe,a0 * See if pointer wrapped
	3291	blt api_g2 * Jump if not
	3292	*
	3293	movea.l #api_fum,a0 * Wrap the pointer around
	3294	*
	3295	api_g2: move.l a0,api_fo * Update pointer
	3296	move.w (a7)+,sr * Restore interrupt mask
	3297	rts * Return to caller
	3298	*
	3299	* api_zap -- clear analog I/O FIFO
	3300	* ------- ---------------------
	3301	api_zap: move.w sr,-(a7) * Save status register
	3302	ori.w #IPL3,sr * Disable ANALOG I/O interrupts
	3303	move.l #api_fum,api_fi * Clear analog processor fifo
	3304	move.l #api_fum,api_fo * ...
	3305	move.w (a7)+,sr * Restore interrupt mask
	3306	rts
	3307	*
	3308	.endc
	3309	*
	3310	.page
	3311	*************************************************************************
	3312	* *
	3313	* Constant definitions *
	3314	* -------------------- *
	3315	*************************************************************************
	3316	*
	3317	.even
	3318	*
	3319	.ifne BUCHLA
	3320	*
	3321	* Buchla 700 tables:
	3322	*
	3323	* t13tab -- Trap-13 pointer table -- Primary BIOS functions
	3324	* ------ -----------------------------------------------
	3325	t13tab: dc.w 12 * Number of Trap-13 routines
	3326	*
	3327	dc.l nullrts * 0 - (getmpb)
	3328	dc.l bconstat * 1 - bconstat
	3329	dc.l bconin * 2 - bconin
	3330	dc.l bconout * 3 - bconout
	3331	dc.l rwabs * 4 - rwabs
	3332	dc.l setexec * 5 - setexec
	3333	dc.l nullrts * 6 - (tickcal)
	3334	dc.l getbpb * 7 - getbpb
	3335	dc.l bcostat * 8 - bcostat
	3336	dc.l mediach * 9 - mediach
	3337	dc.l drvmap * 10 - drvmap
	3338	dc.l nullrts * 11 - (shift)
	3339	*
	3340	.page
	3341	*
	3342	* t14tab -- Trap-14 pointer table -- Extended BIOS functions (Buchla 700 only)
	3343	* ------ ------------------------------------------------------------------
	3344	t14tab: dc.w 10 * Number of trap14 routines
	3345	*
	3346	dc.l piorec * 0 - Get iorec address
	3347	dc.l setport * 1 - Set ACIA parameters
	3348	dc.l floprd * 2 - Read floppy
	3349	dc.l flopwr * 3 - Write floppy
	3350	dc.l flopfmt * 4 - Format floppy
	3351	dc.l flopver * 5 - Verify floppy
	3352	dc.l protobt * 6 - Create prototype boot sec.
	3353	dc.l rand * 7 - Generate random number
	3354	dc.l api_get * 8 - Get analog input
	3355	dc.l api_zap * 9 - Clear analog FIFO
	3356	*
	3357	.endc
	3358	*
	3359	.even
	3360	*
	3361	.ifeq BUCHLA
	3362	*
	3363	* NASA 3D Helmet tables:
	3364	*
	3365	* t13tab -- Trap-13 pointer table -- Primary BIOS functions
	3366	* ------ -----------------------------------------------
	3367	t13tab: dc.w 12 * Number of Trap-13 routines
	3368	*
	3369	dc.l nullrts * 0 - (getmpb)
	3370	dc.l bconstat * 1 - bconstat
	3371	dc.l bconin * 2 - bconin
	3372	dc.l bconout * 3 - bconout
	3373	dc.l nullrts * 4 - (rwabs)
	3374	dc.l setexec * 5 - setexec
	3375	dc.l nullrts * 6 - (tickcal)
	3376	dc.l nullrts * 7 - (getbpb)
	3377	dc.l bcostat * 8 - bcostat
	3378	dc.l nullrts * 9 - (mediach)
	3379	dc.l nullrts * 10 - (drvmap)
	3380	dc.l nullrts * 11 - (shift)
	3381	*
	3382	.page
	3383	*
	3384	* t14tab -- Trap-14 pointer table -- Extended BIOS functions (Buchla 700 only)
	3385	* ------ ------------------------------------------------------------------
	3386	t14tab: dc.w 10 * Number of trap14 routines
	3387	*
	3388	dc.l piorec * 0 - Get iorec address
	3389	dc.l setport * 1 - Set ACIA parameters
	3390	dc.l nullrts * 2 - (Read floppy)
	3391	dc.l nullrts * 3 - (Write floppy)
	3392	dc.l nullrts * 4 - (Format floppy)
	3393	dc.l nullrts * 5 - (Verify floppy)
	3394	dc.l nullrts * 6 - (Create prototype boot sec.)
	3395	dc.l nullrts * 7 - (Generate random number)
	3396	dc.l nullrts * 8 - (Get analog input)
	3397	dc.l nullrts * 9 - (Clear analog FIFO)
	3398	*
	3399	.endc
	3400	*
	3401	.page
	3402	*
	3403	* cdt01 -- Character device dispatch table #1 -- input status
	3404	* ----- --------------------------------------------------
	3405	cdt01: dc.l sr1ist * 0 - PRT -- Printer
	3406	dc.l sr2ist * 1 - AUX -- Serial-2
	3407	dc.l sr2ist * 2 - CON -- Console
	3408	*
	3409	.ifne BUCHLA
	3410	*
	3411	dc.l mc1ist * 3 - MC1 -- MIDI-1
	3412	dc.l mc2ist * 4 - MC2 -- MIDI-2
	3413	*
	3414	.endc
	3415	*
	3416	* cdt02 -- Character device dispatch table #2 -- input
	3417	* ----- -------------------------------------------
	3418	cdt02: dc.l sr1inp * 0 - PRT -- Printer
	3419	dc.l sr2inp * 1 - AUX -- Serial-2
	3420	dc.l sr2inp * 2 - CON -- Console
	3421	*
	3422	.ifne BUCHLA
	3423	*
	3424	dc.l mc1inp * 3 - MC1 -- MIDI-1
	3425	dc.l mc2inp * 4 - MC2 -- MIDI-2
	3426	*
	3427	.endc
	3428	*
	3429	* cdt03 -- Character device dispatch table #3 -- output
	3430	* ----- --------------------------------------------
	3431	cdt03: dc.l sr1out * 0 - PRT -- Printer
	3432	dc.l sr2out * 1 - AUX -- Serial-2
	3433	dc.l sr2out * 2 - CON -- Console
	3434	.ifne BUCHLA
	3435	*
	3436	dc.l mc1out * 3 - MC1 -- MIDI-1
	3437	dc.l mc2out * 4 - MC2 -- MIDI-2
	3438	*
	3439	.endc
	3440	*
	3441	* cdt04 -- Character device dispatch table #4 -- output status
	3442	* ----- ---------------------------------------------------
	3443	cdt04: dc.l sr1ost * 0 - PRT -- Printer
	3444	dc.l sr2ost * 1 - AUX -- Serial-2
	3445	dc.l sr2ost * 2 - CON -- Console
	3446	.ifne BUCHLA
	3447	*
	3448	dc.l mc1ost * 3 - MC1 -- MIDI-1
	3449	dc.l mc2ost * 4 - MC2 -- MIDI-2
	3450	*
	3451	.endc
	3452	*
	3453	.page
	3454	*
	3455	* iorec defaults:
	3456	* ---------------
	3457	* Serial-1:
	3458	* ---------
	3459	sr1dflt: dc.l sr1ibuf
	3460	dc.w SR1IBS
	3461	dc.w 0,0
	3462	dc.w SR1IBS/4
	3463	dc.w SR1IBS-(SR1IBS/4)
	3464	dc.l sr1obuf
	3465	dc.w SR1OBS
	3466	dc.w 0,0
	3467	dc.w SR1OBS/4
	3468	dc.w SR1OBS-(SR1OBS/4)
	3469	dc.b SR1CFR0,SR1CFR1
	3470	dc.b 0,0
	3471	dc.b SR1DISC,0
	3472	dc.b 0,0
	3473	dc.w 0,0
	3474	*
	3475	* Serial-2:
	3476	* ---------
	3477	sr2dflt: dc.l sr2ibuf
	3478	dc.w SR2IBS
	3479	dc.w 0,0
	3480	dc.w SR2IBS/4
	3481	dc.w SR2IBS-(SR2IBS/4)
	3482	dc.l sr2obuf
	3483	dc.w SR2OBS
	3484	dc.w 0,0
	3485	dc.w SR2OBS/4
	3486	dc.w SR2OBS-(SR2OBS/4)
	3487	dc.b SR2CFR0,SR2CFR1
	3488	dc.b 0,0
	3489	dc.b SR2DISC,0
	3490	dc.b 0,0
	3491	dc.w 0,0
	3492	*
	3493	.page
	3494	*
	3495	.ifne BUCHLA
	3496	*
	3497	* MIDI-1:
	3498	* -------
	3499	mc1dflt: dc.l mc1ibuf
	3500	dc.w MC1IBS
	3501	dc.w 0,0
	3502	dc.w MC1IBS/4
	3503	dc.w MC1IBS-(MC1IBS/4)
	3504	dc.l mc1obuf
	3505	dc.w MC1OBS
	3506	dc.w 0,0
	3507	dc.w MC1OBS/4
	3508	dc.w MC1OBS-(MC1OBS/4)
	3509	dc.b MC1CFR0,MC1CFR1
	3510	dc.b 0,0
	3511	dc.b MC1DISC,0
	3512	dc.b 0,0
	3513	dc.w 0,0
	3514	*
	3515	* MIDI-2:
	3516	* -------
	3517	mc2dflt: dc.l mc2ibuf
	3518	dc.w MC2IBS
	3519	dc.w 0,0
	3520	dc.w MC2IBS/4
	3521	dc.w MC2IBS-(MC2IBS/4)
	3522	dc.l mc2obuf
	3523	dc.w MC2OBS
	3524	dc.w 0,0
	3525	dc.w MC2OBS/4
	3526	dc.w MC2OBS-(MC2OBS/4)
	3527	dc.b MC2CFR0,MC2CFR1
	3528	dc.b 0,0
	3529	dc.b MC2DISC,0
	3530	dc.b 0,0
	3531	dc.w 0,0
	3532	*
	3533	.endc
	3534	*
	3535	.page
	3536	*
	3537	* brtable -- Baud rate setup table
	3538	* ------- ---------------------
	3539	brtable: dc.b BR_19K2 * 0 - 19200 baud
	3540	dc.b BR_9600 * 1 - 9600 baud
	3541	dc.b BR_4800 * 2 - 4800 baud
	3542	dc.b BR_3600 * 3 - 3600 baud
	3543	dc.b BR_2400 * 4 - 2400 baud
	3544	dc.b BR_7200 * 5 - 7200 baud (2000 on Atari)
	3545	dc.b BR_1800 * 6 - 1800 baud
	3546	dc.b BR_1200 * 7 - 1200 baud
	3547	dc.b BR_600 * 8 - 600 baud
	3548	dc.b BR_300 * 9 - 300 baud
	3549	*
	3550	* iortab -- iorec pointer table
	3551	* ------ -------------------
	3552	iortab: dc.l sr1iorec * 0 - PRT Serial-1 Printer
	3553	dc.l sr2iorec * 1 - AUX Serial-2 Host
	3554	dc.l sr2iorec * 2 - CON Serial-2 Console
	3555	*
	3556	.ifne BUCHLA
	3557	*
	3558	dc.l mc1iorec * 3 - MC1 MIDI-1 MIDI port #1
	3559	dc.l mc2iorec * 4 - MC2 MIDI-2 MIDI port #2
	3560	*
	3561	.endc
	3562	*
	3563	* aciatab -- iorec and ACIA pointer table
	3564	* ------- ----------------------------
	3565	aciatab: dc.l sr1iorec,SR1ACIA * 0 - PRT Serial-1
	3566	dc.l sr2iorec,SR2ACIA * 1 - AUX Serial-2
	3567	dc.l sr2iorec,SR2ACIA * 2 - CON Serial-2
	3568	*
	3569	.ifne BUCHLA
	3570	*
	3571	dc.l mc1iorec,MC1ACIA * 3 - MC1 MIDI-1
	3572	dc.l mc2iorec,MC2ACIA * 4 - MC2 MIDI-2
	3573	*
	3574	.endc
	3575	*
	3576	.page
	3577	*
	3578	.ifne BUCHLA
	3579	*
	3580	* pbpbtab -- Prototype BPB data table (BPS..NHID) 19 bytes per entry
	3581	* ------- ---------------------------------------------------------
	3582	*
	3583	* 0 -- 40 tracks, single sided (180K)
	3584	*
	3585	pbpbtab: dc.b $00,$02,$01,$01,$00,$02,$40,$00
	3586	dc.b $68,$01,$FC,$02,$00,$09,$00,$01
	3587	dc.b $00,$00,$00
	3588	*
	3589	* 1 -- 40 tracks, double sided (360K)
	3590	*
	3591	dc.b $00,$02,$02,$01,$00,$02,$70,$00
	3592	dc.b $D0,$02,$FD,$02,$00,$09,$00,$02
	3593	dc.b $00,$00,$00
	3594	*
	3595	* 2 -- 80 tracks, single sided (360K)
	3596	*
	3597	dc.b $00,$02,$02,$01,$00,$02,$70,$00
	3598	dc.b $D0,$02,$F8,$05,$00,$09,$00,$01
	3599	dc.b $00,$00,$00
	3600	*
	3601	* 3 -- 80 tracks, double sided (720K)
	3602	*
	3603	dc.b $00,$02,$02,$01,$00,$02,$70,$00
	3604	dc.b $A0,$05,$F9,$05,$00,$09,$00,$02
	3605	dc.b $00,$00,$00
	3606	*
	3607	* VSDD initialization table
	3608	*
	3609	.even
	3610	*
	3611	vsddtab: dc.w $8252 * R0 Mode word 0
	3612	dc.w $E474 * R1 Mode word 1
	3613	dc.w $0006 * R2 Register window base
	3614	dc.w $0100 * R3 Data window base
	3615	dc.w $0000 * R4 Data length mask
	3616	dc.w $0000 * R5 Data segment base
	3617	dc.w $0001 * R6 Priority access count
	3618	dc.w $0040 * R7 ODT base
	3619	dc.w $0080 * R8 AT base
	3620	dc.w $0010 * R9 CLT base
	3621	dc.w $0011 * R10 CG bases
	3622	dc.w $0000 * R11 AT counter (R/O)
	3623	*
	3624	dc.w $0C08 * R12 HC0 = 3, VC0 = 8
	3625	dc.w $140A * R13 HC1 = 5, VC1 = 10
	3626	dc.w $9568 * R14 HC2 = 37, VC2 = 360
	3627	dc.w $A16A * R15 HC3 = 40, VC3 = 362
	3628	*
	3629	vsddit01: dc.w $8253 * R0 with UCF = 1, DEN = 0
	3630	vsddit02: dc.w $825B * R0 with UCF = 1, DEN = 1
	3631	*
	3632	.page
	3633	*
	3634	* analog processor input state table
	3635	*
	3636	api_tab: dc.b 0,1,1,1,1,1,1,1,1,1 * 0..9
	3637	dc.b 1,1,1,1,1,1,1,1,1,1 * 10..19
	3638	dc.b 1,1,1,1,1 * 20..24
	3639	dc.b 3,3,3,3,3 * 25..29
	3640	dc.b 3,3,3,3,3,3,3,3,3 * 30..38
	3641	dc.b 5 * 39
	3642	dc.b 5,5,5,5,5,5,5,5,5,5 * 40..49
	3643	dc.b 5,5,5 * 50..52
	3644	dc.b 3,3,3,3,3,3,3 * 53..59
	3645	dc.b 5,5,5,5,5,5,5,5,5,5 * 60..69
	3646	dc.b 5,5,5 * 70..72
	3647	dc.b 6,6,6,6,6,6,6 * 73..79
	3648	dc.b 6,6,6 * 80..82
	3649	*
	3650	.even
	3651	*
	3652	* analog processor state transfer vector
	3653	*
	3654	api_tv: dc.l api_s0,api_s1,api_s2,api_s3
	3655	dc.l api_s4,api_s5,api_s6
	3656	*
	3657	.endc
	3658	*
	3659	.page
	3660	*************************************************************************
	3661	* *
	3662	* RAM storage definitions *
	3663	* ----------------------- *
	3664	*************************************************************************
	3665	*
	3666	.bss
	3667	.even
	3668	*
	3669	* RAM data area
	3670	* -------------
	3671	* WARNING:
	3672	* --------
	3673	* The variables from timevec through rsarea are permanently assigned so
	3674	* that we can link to certain bios variables without having to link to the
	3675	* bios object file itself. Some of these get defined in hwdefs.s and in
	3676	* hwdefs.s so beware of changing them.
	3677	*
	3678	timevec: ds.l 1 * System timer trap vector
	3679	critvec: ds.l 1 * Critical error handler vector
	3680	termvec: ds.l 1 * Process terminate hook vector
	3681	resvec3: ds.l 1 * Reserved vector 3
	3682	resvec4: ds.l 1 * Reserved vector 4
	3683	resvec5: ds.l 1 * Reserved vector 5
	3684	resvec6: ds.l 1 * Reserved vector 6
	3685	resvec7: ds.l 1 * Reserved vector 7
	3686	*
	3687	fc_sw: ds.w 1 * Frame clock switch (<0=dn, 0=off, >0=up)
	3688	fc_val: ds.l 1 * Frame clock value (0..FCMAX)
	3689	*
	3690	_wzcrsh: ds.w 1 * Crash area: flag for ROMP
	3691	_crshsr: ds.w 1 * Crash area: SR
	3692	_crshpc: ds.l 1 * Crash area: PC
	3693	_crshsp: ds.l 1 * Crash area: SP
	3694	_crshus: ds.l 1 * Crash area: USP
	3695	_crshvc: ds.l 1 * Crash area: vector # in MS byte
	3696	_crshrg: ds.l 16 * Crash area: registers
	3697	_crshst: ds.w 16 * Crash area: top 16 words of stack
	3698	*
	3699	* The area from biosram to SSTACK-1 is cleared on reset.
	3700	* ------------------------------------------------------
	3701	biosram .equ * * Start of BIOS RAM variables
	3702	*
	3703	.ifne BUCHLA
	3704	*
	3705	_hz_1k: ds.l 1 * 1000 Hz clock
	3706	_hz_200: ds.l 1 * 200 Hz clock
	3707	frclock: ds.l 1 * 50 Hz clock
	3708	t1count: ds.w 1 * Timer 1 count
	3709	t2count: ds.w 1 * Timer 2 count
	3710	t3count: ds.w 1 * Timer 3 count
	3711	*
	3712	seekrate: ds.w 1 * Seek rate
	3713	cdev: ds.w 1 * Current drive
	3714	ctrack: ds.w 1 * Current track
	3715	csect: ds.w 1 * Current sector
	3716	cside: ds.w 1 * Current side
	3717	ccount: ds.w 1 * Current sector count
	3718	spt: ds.w 1 * Sectors per track
	3719	interlv: ds.w 1 * Sector interleave count
	3720	virgin: ds.w 1 * Initial formatting data
	3721	deferr: ds.w 1 * Default error number
	3722	curerr: ds.w 1 * Current error number
	3723	*
	3724	cdma: ds.l 1 * Current DMA address
	3725	edma: ds.l 1 * Ending DMA address
	3726	tmpdma: ds.l 1 * Temporary DMA address
	3727	*
	3728	.endc
	3729	*
	3730	rseed: ds.l 1 * Random number seed
	3731	*
	3732	savptr: ds.l 1 * Pointer to register save area
	3733	*
	3734	_rsflag: ds.l 1 * Register save area overflow flag
	3735	ds.l 1832 Register save area (32 levels)
	3736	rsarea: ds.l 1 * Dummy long word at top of save area
	3737	*
	3738	* *** end of the permanently assigned bios variables ***
	3739	*
	3740	.page
	3741	*
	3742	.ifne BUCHLA
	3743	*
	3744	acctim: ds.l 2 * Accumulated disk time table
	3745	maxactim: ds.l 1 * Maximum acctim value
	3746	hdv_init: ds.l 1 * Disk init vector
	3747	hdv_bpb: ds.l 1 * Disk get bpb vector
	3748	hdv_rw: ds.l 1 * Disk r/w vector
	3749	hdv_boot: ds.l 1 * Disk boot vector
	3750	hdv_mchg: ds.l 1 * Disk media change vector
	3751	drvbits: ds.l 1 * Drive map bits
	3752	dskbufp: ds.l 1 * Disk buffer pointer
	3753	.page
	3754	nflops: ds.w 1 * Number of drives
	3755	disknum: ds.w 1 * Current disk number
	3756	booted: ds.w 1 * Most recent boot device or -1
	3757	flock: ds.w 1 * Floppy semaphore
	3758	fverify: ds.w 1 * Floppy verify flag
	3759	*
	3760	tdiv1: ds.w 1 * Timer divider 1 (divides _hz_1k)
	3761	tdiv2: ds.w 1 * Timer divider 2 (divides _hz_200)
	3762	*
	3763	retrycnt: ds.w 1 * Re-try count
	3764	wpstatus: ds.w 1 * Write protect status table
	3765	wplatch: ds.w 1 * Write protect latch table
	3766	bootdev: ds.w 1 * Boot device number
	3767	*
	3768	motoron: ds.w 1 * Motor-on flag
	3769	deslflag: ds.w 1 * Drive deselect flag
	3770	*
	3771	.endc
	3772	*
	3773	flpsrsv: ds.w 1 * Status register save area
	3774	flpregs: ds.l 16 * Register save area
	3775	*
	3776	.ifne BUCHLA
	3777	*
	3778	dsb0: ds.l 1 * Drive A DSB
	3779	dsb1: ds.l 1 * Drive B DSB
	3780	*
	3781	dskmode: ds.b 2 * Disk change mode table
	3782	dskerrs: ds.w 2 * Disk error code table
	3783	drvbpbs: ds.w 162 Disk BPB save area
	3784	*
	3785	.endc
	3786	*
	3787	.page
	3788	*
	3789	sr1iorec: ds.b IORECLN * Serial-1 iorec structure
	3790	sr2iorec: ds.b IORECLN * Serial-2 iorec structure
	3791	*
	3792	.ifne BUCHLA
	3793	*
	3794	mc1iorec: ds.b IORECLN * MIDI-1 iorec structure
	3795	mc2iorec: ds.b IORECLN * MIDI-2 iorec structure
	3796	*
	3797	.endc
	3798	*
	3799	sr1ibuf: ds.b SR1IBS * Serial-1 input buffer
	3800	sr1obuf: ds.b SR1OBS * Serial-1 output buffer
	3801	sr2ibuf: ds.b SR2IBS * Serial-2 input buffer
	3802	sr2obuf: ds.b SR2OBS * Serial-2 output buffer
	3803	*
	3804	.ifne BUCHLA
	3805	*
	3806	mc1ibuf: ds.b MC1IBS * MIDI-1 input buffer
	3807	mc1obuf: ds.b MC1OBS * MIDI-1 output buffer
	3808	mc2ibuf: ds.b MC2IBS * MIDI-2 input buffer
	3809	mc2obuf: ds.b MC2OBS * MIDI-2 output buffer
	3810	*
	3811	api_inp: ds.b 1 * Analog processor input byte
	3812	api_bug: ds.b 1 * Analog processor signal # "bug trap"
	3813	api_sv: ds.b 1 * Analog processor state
	3814	api_svb: ds.b 1 * Analog processor state "bug trap"
	3815	*
	3816	.even
	3817	*
	3818	api_sig: ds.b 1 * Analog signal number
	3819	api_val: ds.b 1 * Analog value
	3820	*
	3821	api_fi: ds.l 1 * Analog processor FIFO input pointer
	3822	api_fo: ds.l 1 * Analog processor FIFO output pointer
	3823	api_fum: ds.w APISIZE * Analog processor FIFO
	3824	api_fe .equ * * End of analog processor FIFO
	3825	*
	3826	.endc
	3827	*
	3828	.even
	3829	*
	3830	basepage: ds.l 64 * Pseudo base page
	3831	*
	3832	buffer: ds.b 1024 * Default disk buffer
	3833	*
	3834	biostop .equ * * End of BIOS RAM
	3835	*
	3836	.end

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