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bios.s@ 3ac8e1b

Last change on this file since 3ac8e1b was 3370595, checked in by Thomas Lopatic <thomas@…>, 7 years ago
Fix symbol collisions.
Property mode set to `100644`
File size: 104.3 KB

Line
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 = 18 \| First part of version number
34	VM2 = 0 \| Second part of version number
35	VDATE = 0x19880620 \| Version date
36
37	BUCHLA = 1 \| Non-Zero for Buchla 700, 0 for NASA
38	NASASIO = 0 \| Non-zero for NASA, 0 for Buchla addr.
39
40	FL_SKR = 0x00 \| 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 = 0x0300 \| IPL 3 value for sr
123	IPL4 = 0x0400 \| IPL 4 value for sr
124	IPL7 = 0x0700 \| IPL 7 value for sr (4 for debug)
125
126	.ifne BUCHLA
127
128	INITIPL = IPL3+0x2000 \| Initial Internal Priority Level
129
130	.endc
131
132	.ifeq BUCHLA
133
134	INITIPL = IPL4+0x2000 \| Initial Internal Priority Level
135
136	.endc
137
138	\| Memory allocation
139	\| -----------------
140	.ifeq BUCHLA
141
142	TPA = 0x008000 \| Put TPA 32K up from the bottom
143
144	.endc
145
146	.ifne BUCHLA
147
148	TPA = 0x010000 \| Put TPA 64K up from the bottom
149
150	.endc
151
152	SSTACK = TPA \| Put system stack just below TPA
153
154	p_bbase = 0x0018 \| Basepage offset to bss base
155	p_blen = 0x001C \| Basepage offset to bss length
156
157	\| It's magic ...
158	\| --------------
159	FMAGIC = 0x87654321 \| Magic for formatting
160	RETRYIT = 0x10000 \| Magic for re-try from criter
161	RSMAGIC = 0x78563412 \| Magic for register save area OK
162
163	\| Miscellaneous constants
164	\| -----------------------
165	FCMAX = 0x00FFFFFF \| Maximum frame counter value (24 bits)
166
167	.page
168
169	\| CFR0 Baud Rates:
170	\| ----------------
171	BR_300 = 0x04
172	BR_600 = 0x05
173	BR_1200 = 0x06
174	BR_1800 = 0x07
175	BR_2400 = 0x08
176	BR_3600 = 0x09
177	BR_4800 = 0x0A
178	BR_7200 = 0x0B
179	BR_9600 = 0x0C
180	BR_19K2 = 0x0D
181	BR_EXT = 0x0F
182
183	\| CFR0 Stop bits (includes TBR select bit):
184	\| -----------------------------------------
185	NSB_1 = 0x40
186	NSB_2 = 0x60
187
188	\| CFR1 Number of Data Bits (includes MSB):
189	\| ----------------------------------------
190	NDB_5 = 0x80
191	NDB_6 = 0xA0
192	NDB_7 = 0xC0
193	NDB_8 = 0xE0
194
195	\| CFR1 Parity Selection:
196	\| ----------------------
197	P_ODD = 0x04
198	P_EVEN = 0x0C
199	P_MARK = 0x14
200	P_SPACE = 0x1C
201
202	P_NONE = 0x00
203
204	\| Line Discipline:
205	\| ----------------
206	L_NUL = 0x00 \| No protocol
207	L_XON = 0x01 \| XON/XOFF
208	L_RTS = 0x02 \| RTS/CTS
209
210	.page
211
212	\| I/O Buffer Sizes:
213	\| -----------------
214	SR1IBS = 256
215	SR1OBS = 256
216	SR2IBS = 256
217	SR2OBS = 256
218
219	.ifne BUCHLA
220
221	MC1IBS = 512
222	MC1OBS = 256
223	MC2IBS = 512
224	MC2OBS = 256
225
226	.endc
227
228	\| Line Disciplines:
229	\| -----------------
230	SR1DISC = L_XON
231	SR2DISC = L_XON
232
233	.ifne BUCHLA
234
235	MC1DISC = L_NUL
236	MC2DISC = L_NUL
237
238	.endc
239
240	\| CFR Setings:
241	\| ------------
242	SR1CFR0 = BR_9600+NSB_1
243	SR1CFR1 = NDB_8+P_NONE
244	SR2CFR0 = BR_9600+NSB_1
245	SR2CFR1 = NDB_8+P_NONE
246
247	.ifne BUCHLA
248
249	MC1CFR0 = BR_EXT+NSB_1
250	MC1CFR1 = NDB_8+P_NONE
251	MC2CFR0 = BR_EXT+NSB_1
252	MC2CFR1 = NDB_8+P_NONE
253
254	.endc
255
256	.page
257
258	\| I/O Addresses:
259	\| --------------
260	VSDDINIT = 0x200400 \| VSDD initial register base address
261	VSDDDATA = 0x200000 \| VSDD data segment base address
262
263	.ifeq BUCHLA
264
265	.ifeq NASASIO
266
267	SR1ACIA = 0x3A8001 \| Serial-1 ACIA base address (BUCHLA)
268	SR2ACIA = 0x3A8009 \| Serial-2 ACIA base address
269
270	.endc
271
272	.ifne NASASIO
273
274	SR1ACIA = 0x398001 \| Serial-1 ACIA base address (NASA)
275	SR2ACIA = 0x398009 \| Serial-2 ACIA base address
276
277	.endc
278
279	.endc
280
281	.ifne BUCHLA
282
283	FPUBASE = 0x180000 \| FPU base address
284	TIMER = 0x3A0001 \| Timer base address
285	LCD = 0x3A4001 \| LCD driver base address
286	SR1ACIA = 0x3A8001 \| Serial-1 ACIA base address (BUCHLA)
287	SR2ACIA = 0x3A8009 \| Serial-2 ACIA base address
288	MC1ACIA = 0x3AC001 \| MIDI-1 ACIA base address
289	MC2ACIA = 0x3AC009 \| MIDI-2 ACIA base address
290	FLOPPY = 0x3B0001 \| Floppy controller base address
291	PSG = 0x3B4001 \| Sound chip base address
292	LEDS = 0x3B8001 \| LED driver base address
293	ANALOG = 0x3BC001 \| Analog processor base address
294
295	\| FPU address offsets and misc. values
296
297	FPU_CTL = 0x4000 \| FPU control
298
299	FPU_IN = 0x4000 \| FPU input address
300	FPU_CLR = 0x6000 \| FPU interrupt reset address
301
302	FPU_RST = 0x0015 \| FPU reset value
303
304	\| PSG address offsets
305
306	PSG_RD = PSG \| Read PSG data
307	PSG_WL = PSG \| Write PSG address latch
308	PSG_WD = PSG+2 \| Write PSG data
309
310	.endc
311
312	\| VSDD data structure offsets
313
314	VSDD_REG = VSDDDATA \| Registers
315	VSDD_AT = VSDDDATA+0x0100 \| Access Table
316
317	.ifne BUCHLA
318
319	\| Timer registers
320
321	TIME_CRX = TIMER \| Control register 1 or 3
322	TIME_CR2 = TIMER+2 \| Control register 2
323	TIME_T1H = TIMER+4 \| Timer 1 high byte
324	TIME_T1L = TIMER+6 \| Timer 1 low byte
325	TIME_T2H = TIMER+8 \| Tiemr 2 high byte
326	TIME_T2L = TIMER+10 \| Timer 2 low byte
327	TIME_T3H = TIMER+12 \| Timer 3 high byte
328	TIME_T3L = TIMER+14 \| Timer 3 low byte
329
330	.endc
331
332	\| ACIA Register offsets:
333	\| ----------------------
334	ACIA_IER = 0 \| ACIA IER offset
335	ACIA_ISR = 0 \| ACIA ISR offset
336	ACIA_CSR = 2 \| ACIA CSR offset
337	ACIA_CFR = 2 \| ACIA CFR offset
338	ACIA_TBR = 4 \| ACIA TBR offset
339	ACIA_TDR = 6 \| ACIA TDR offset
340	ACIA_RDR = 6 \| ACIA RDR offset
341
342	.page
343
344	.ifne BUCHLA
345
346	\| Floppy register offsets:
347	\| ------------------------
348	DSKCMD = 0 \| Command / status
349	DSKTRK = 2 \| Track
350	DSKSEC = 4 \| Sector
351	DSKDAT = 6 \| Data
352
353	\| Miscellaneous equates:
354	\| ----------------------
355	FL_NC = 0x02 \| Non-compensated R/W/F bit
356
357	APISIZE = 256 \| Analog processor buffer size
358
359	\| Floppy commands:
360	\| ----------------
361	FL_RS = 0x80 \| Read sector
362	FL_RM = 0x90 \| Read multiple
363	FL_WS = 0xA0 \| Write sector
364	FL_WT = 0xF0 \| Write track (format)
365	FL_FR = 0xD0 \| Force reset
366	FL_SK = 0x10 \| Seek
367	FL_SV = 0x14 \| Seek w/verify
368
369	.endc
370
371	.page
372
373	\| iorec structure definitions:
374	\| ----------------------------
375	IORECLN = 40 \| Length of an iorec structure
376
377	ibuf = 0 \| Input buffer base address
378	ibufsize = 4 \| Input buffer size (bytes)
379	ibufhd = 6 \| Input buffer head index
380	ibuftl = 8 \| Input buffer tail index
381	ibuflow = 10 \| Input buffer low water mark
382	ibufhi = 12 \| Input buffer high water mark
383	obuf = 14 \| Output buffer base address
384	obufsize = 18 \| Output buffer size (bytes)
385	obufhd = 20 \| Output buffer head index
386	obuftl = 22 \| Output buffer tail index
387	obuflow = 24 \| Output buffer low water mark
388	obufhi = 26 \| Output buffer high water mark
389	cfr0 = 28 \| ACIA CFR, MS bit = 0
390	cfr1 = 29 \| ACIA CFR, MS bit = 1
391	flagxon = 30 \| XON flag (non-zero = XOFF sent)
392	flagxoff = 31 \| XOFF flag (non-zero = active)
393	linedisc = 32 \| Line discipline flags
394	erbyte = 33 \| Last error byte
395	isr = 34 \| ACIA ISR on interrupt
396	csr = 35 \| ACIA CSR on interrupt
397	errct = 36 \| Error count (FRM/OVR/BRK)
398	ibfct = 38 \| Input buffer full count
399
400	.page
401
402	\| Error codes:
403	\| ------------
404	ERR01 = -1 \| All purpose error
405	ERR02 = -2 \| Drive not ready
406	ERR03 = -3 \| Unknown command
407	ERR04 = -4 \| CRC Error
408	ERR05 = -5 \| Invalid request
409	ERR06 = -6 \| Seek error
410	ERR07 = -7 \| Unknown media
411	ERR08 = -8 \| Sector not found
412	ERR09 = -9 \| End of media (out of paper)
413	ERR10 = -10 \| Write fault
414	ERR11 = -11 \| Read fault
415	ERR12 = -12 \| General mishap
416	ERR13 = -13 \| Write protected
417	ERR14 = -14 \| Media changed
418	ERR15 = -15 \| Unknown device
419	ERR16 = -16 \| Bad sectors
420	ERR17 = -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: .ascii "{Copyright 1988 by " \| Copyright message
440	.asciz "D.N. Lynx Crowe}"
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 #0x2700,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 #0x02000000,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 #0x01000000,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,0x0008 \| Set bus error vector
481	move.l #nullrte,0x0014 \| Set divide error vector
482	move.l #nullrte,0x0018 \| Set CHK vector
483	move.l #nullrte,0x001C \| Set TRAPV vector
484	move.l #nullrte,0x0024 \| Set trace vector
485
486	move.l #nullrte,0x0030 \| Set reserved vector 12
487	move.l #nullrte,0x0034 \| Set reserved vector 13
488	move.l #nullrte,0x0038 \| Set reserved vector 14
489
490	move.l #nullrte,0x003C \| Set uninitialized int. vector
491
492	move.l #nullrte,0x0040 \| Set reserved vector 16
493	move.l #nullrte,0x0044 \| Set reserved vector 17
494	move.l #nullrte,0x0048 \| Set reserved vector 18
495	move.l #nullrte,0x004C \| Set reserved vector 19
496	move.l #nullrte,0x0050 \| Set reserved vector 20
497	move.l #nullrte,0x0054 \| Set reserved vector 21
498	move.l #nullrte,0x0058 \| Set reserved vector 22
499	move.l #nullrte,0x005C \| Set reserved vector 23
500
501	move.l #nullrte,0x0060 \| Set spurious int. vector
502
503	move.l #serintr,0x0074 \| Set ACIA interrupt vector
504	move.l #nullrte,0x0078 \| Set level 6 vector
505	move.l #nullrte,0x007C \| Set level 7 vector
506
507	move.l #trap13_,0x00B4 \| Set trap13 vector
508	move.l #trap14_,0x00B8 \| Set trap14 vector
509
510	.page
511
512	.ifne BUCHLA
513
514	move.l #nullfpu,0x0068 \| Set FPU interrupt vector
515	move.l #api_int,0x006C \| Set analog trap vector
516	move.l #timeint,0x0070 \| 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 #0xFFFF,fverify \| Set read after write flag
525	move.w #FL_SKR,seekrate \| Set default seek rate
526	move.w #0xFFFF,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 #0x80,PSG_WD \| Write 0x80 (port B = output)
533	move.b #15,PSG_WL \| Select PSG R15
534	move.b #0x00,PSG_WD \| Write 0x00 (sync enable)
535
536	move.b #0x00,TIME_T1H \| Setup timer 1 (PLL)
537	move.b #0x1F,TIME_T1L \| ... for divide by 64
538	move.b #0x0C,TIME_T2H \| Setup timer 2 (FC)
539	move.b #0x7F,TIME_T2L \| ... for divide by 3200
540	move.b #0x03,TIME_T3H \| Setup timer 3 (RTC)
541	move.b #0x20,TIME_T3L \| ... for 1Ms interval
542	move.b #0x42,TIME_CRX \| Setup CR3
543	move.b #0x41,TIME_CR2 \| Setup CR2
544	move.b #0x81,TIME_CRX \| Setup CR1
545	move.b #0x80,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 #0x80,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 #0x18,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 #0x0000,0x08(a0) \| Set CV1 to 0
609	addq.w #1,d0 \| Delay
610	addq.w #1,d0 \| ...
611	move.w #0x0000,0x0A(a0) \| Set SF1 to 0
612	addq.w #1,d0 \| Delay
613	addq.w #1,d0 \| ...
614	move.w #0x0000,0x0C(a0) \| Set CV2 to 0
615	addq.w #1,d0 \| Delay
616	addq.w #1,d0 \| ...
617	move.w #0x0000,0x0E(a0) \| Set SF2 to 0
618	addq.w #1,d0 \| Delay
619	addq.w #1,d0 \| ...
620	move.w #0x0000,0x10(a0) \| Set CV3 to 0
621	addq.w #1,d0 \| Delay
622	addq.w #1,d0 \| ...
623	move.w #0x0000,0x12(a0) \| Set SF3 to 0
624	addq.w #1,d0 \| Delay
625	addq.w #1,d0 \| ...
626	move.w #0x8300,0x02(a0) \| Set new value '10' to -10.00
627	addq.w #1,d0 \| Delay
628	addq.w #1,d0 \| ...
629	move.w #0x8300,0x1C(a0) \| Set new value '01' to -10.00
630	addq.w #1,d0 \| Delay
631	addq.w #1,d0 \| ...
632	move.w #0x0001,0x16(a0) \| Set exponent for shortest time
633	addq.w #1,d0 \| Delay
634	addq.w #1,d0 \| ...
635	move.w #0xFFF0,0x14(a0) \| Set mantissa for shortest time
636	addq.w #1,d0 \| Delay
637	addq.w #1,d0 \| ...
638	move.w #0x0005,0x00(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 #0x000000FF,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 #0x2700 \| 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 #0xFFFFFFFE,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 #0xFFFF,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 #0xFFFF,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 #0xFFFE,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 #0x0001,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 #0x11,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 #0xFFFE,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 #0x0001,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 #0xFFFE,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 #0x0001,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 #0x11,d0 \| Is this an XON ?
1356	bne serrx2 \| Jump if not
1357
1358	move.b #0x00,flagxoff(a0) \| Clear flagxoff
1359	bra sertxq \| Done
1360
1361	serrx2: cmpi.b #0x13,d0 \| Is this an XOFF ?
1362	bne serrx3 \| Jump if not
1363
1364	move.b #0xFF,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 #0xFF,flagxon(a0) \| Set the flag
1389	move.b #0x13,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 #0x0070,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 #0x7F,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 #0xC3,ACIA_IER(a1) \| Enable TDRE, RDRF
1583	bra aciai_3 \| Go return
1584
1585	aciai_2: move.b #0xE3,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 0x3F,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 #0xFF,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 #0xFF,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 #0xFF,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 #0xFF00,0(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 #0x40000,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 #0x40000,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 #0x1C,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 #0x40000,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 #0x5C,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 #0x4E,d0 \| Write 0x4E 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 0x00 as sync
2436	bsr wmult \| ...
2437	move.w #3-1,d1 \| Set count = 3
2438	move.b #0xF5,d0 \| Write 0xF5's
2439	bsr wmult \| ...
2440	move.b #0xFE,(a2)+ \| Write 0xFE (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 #0xF7,(a2)+ \| Write checksum code
2446	move.w #22-1,d1 \| Set count = 22
2447	move.b #0x4E,d0 \| Write gap
2448	bsr wmult \| ...
2449	move.w #12-1,d1 \| Set count = 12
2450	clr.b d0 \| Write 0x00 as sync
2451	bsr wmult \| ...
2452	move.w #3-1,d1 \| Set count = 3
2453	move.b #0xF5,d0 \| Write 0xF5's
2454	bsr wmult \| ...
2455	move.b #0xFB,(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 #0xF7,(a2)+ \| Write CRC code
2465	move.w #40-1,d1 \| Set count = 40
2466	move.b #0x4E,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 #0x4E,d0 \| Write final gap
2478	bsr wmult \| ...
2479	move.l cdma(a5),a2 \| Get buffer address
2480	move.l #0x40000,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 #0x44,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 #0x40000,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 #0x40000,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 #0x1C,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 #0xFF00,0(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 #0x18,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 #0x3,d0 \| ...
2810	or.b d0,d6 \| OR into command word
2811	move.l #0x40000,d7 \| Set timeout counter
2812	btst #7,DSKCMD(a6) \| Motor on ?
2813	bne flopcm01 \| Jump if so
2814
2815	move.l #0x60000,d7 \| Set longer timeout count
2816
2817	flopcm01: move.b d6,DSKCMD(a6) \| Write command from d6
2818
2819	move.l #0x1000,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 #0xFE,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 #0xFFFF,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 #0x1234,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 #0xBB40E62D,-(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 #0xFFFFFF,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 #0x1234,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 #0xFFFFFF,d0 \| > 0xFFFFFF
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 #0xFF,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 #0x1FE,d0 \| Plus sector length
3149	cmp.l -4(a6),d0 \| Done ?
3150	bhi protbt11 \| Loop if not
3151
3152	move.w #0x1234,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 #0x7F,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 #0x80,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 #0x80,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 #0x80,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 0x00,0x02,0x01,0x01,0x00,0x02,0x40,0x00
3586	.dc.b 0x68,0x01,0xFC,0x02,0x00,0x09,0x00,0x01
3587	.dc.b 0x00,0x00,0x00
3588
3589	\| 1 -- 40 tracks, double sided (360K)
3590
3591	.dc.b 0x00,0x02,0x02,0x01,0x00,0x02,0x70,0x00
3592	.dc.b 0xD0,0x02,0xFD,0x02,0x00,0x09,0x00,0x02
3593	.dc.b 0x00,0x00,0x00
3594
3595	\| 2 -- 80 tracks, single sided (360K)
3596
3597	.dc.b 0x00,0x02,0x02,0x01,0x00,0x02,0x70,0x00
3598	.dc.b 0xD0,0x02,0xF8,0x05,0x00,0x09,0x00,0x01
3599	.dc.b 0x00,0x00,0x00
3600
3601	\| 3 -- 80 tracks, double sided (720K)
3602
3603	.dc.b 0x00,0x02,0x02,0x01,0x00,0x02,0x70,0x00
3604	.dc.b 0xA0,0x05,0xF9,0x05,0x00,0x09,0x00,0x02
3605	.dc.b 0x00,0x00,0x00
3606
3607	\| VSDD initialization table
3608
3609	.even
3610
3611	vsddtab: .dc.w 0x8252 \| R0 Mode word 0
3612	.dc.w 0xE474 \| R1 Mode word 1
3613	.dc.w 0x0006 \| R2 Register window base
3614	.dc.w 0x0100 \| R3 Data window base
3615	.dc.w 0x0000 \| R4 Data length mask
3616	.dc.w 0x0000 \| R5 Data segment base
3617	.dc.w 0x0001 \| R6 Priority access count
3618	.dc.w 0x0040 \| R7 ODT base
3619	.dc.w 0x0080 \| R8 AT base
3620	.dc.w 0x0010 \| R9 CLT base
3621	.dc.w 0x0011 \| R10 CG bases
3622	.dc.w 0x0000 \| R11 AT counter (R/O)
3623
3624	.dc.w 0x0C08 \| R12 HC0 = 3, VC0 = 8
3625	.dc.w 0x140A \| R13 HC1 = 5, VC1 = 10
3626	.dc.w 0x9568 \| R14 HC2 = 37, VC2 = 360
3627	.dc.w 0xA16A \| R15 HC3 = 40, VC3 = 362
3628
3629	vsddit01: .dc.w 0x8253 \| R0 with UCF = 1, DEN = 0
3630	vsddit02: .dc.w 0x825B \| 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: \| 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 18*32 \| 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 16*2 \| 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: \| 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: \| End of BIOS RAM
3835
3836	.end

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