source: buchla-68k/orig/IOLIB/PTCL12.S@ 7bf3856

Last change on this file since 7bf3856 was 3ae31e9, checked in by Thomas Lopatic <thomas@…>, 8 years ago

Imported original source code.
  • Property mode set to 100755
File size: 965 bytes
Line 
1* ------------------------------------------------------------------------------
2* ptcl12.s -- store a cluster entry into the FAT
3* Version 2 -- 1987-10-27 -- D.N. Lynx Crowe
4* ------------------------------------------------------------------------------
5 .text
6 .xdef __ptcl12
7*
8CL .equ 12
9VAL .equ 14
10CLA .equ d7
11CLP .equ d6
12CLT .equ d5
13FAT .equ a5
14*
15__ptcl12: link A6,#0
16 movem.l CLT-CLA/FAT-FAT,-(sp)
17 move.l 8(A6),FAT
18 move.w CL(A6),CLA
19 lsr.w CLA
20 add.w CL(A6),CLA
21 move.b 1(FAT,CLA.W),CLP
22 lsl.w #8,CLP
23 move.b 0(FAT,CLA.W),CLP
24 btst #0,CL+1(A6)
25 beq L2
26*
27 move.w CLP,CLT
28 and.w #$000F,CLT
29 move.w VAL(A6),D0
30 lsl.w #4,D0
31 or.w D0,CLT
32 bra L3
33*
34L2: move.w CLP,CLT
35 and.w #$F000,CLT
36 move.w VAL(A6),D0
37 and.w #$0FFF,D0
38 or.w D0,CLT
39*
40L3: move.b CLT,0(FAT,CLA.W)
41 move.w CLT,D0
42 lsr.w #8,D0
43 move.b D0,1(FAT,CLA.W)
44*
45L1: movem.l (sp)+,CLT-CLA/FAT-FAT
46 unlk A6
47 rts
48*
49 .end
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