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apple2_fantavision_reloaded
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Replace non-descript 'Buff' with 'Dest'

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Michaelangel007 2017-03-26 12:47:50 -07:00
parent 2bc8436374
commit 241f0b43fa
1 changed files with 7 additions and 7 deletions
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@ -311,7 +311,7 @@ but I'll be nice guy and provide a fully documented disassembly:
```asm
; Disk Drive P5 PROM Usage ZP and IO
P5.Buff = $26 ; 16-bit pointer to dest
P5.Dest = $26 ; 16-bit pointer to dest
P5.SlotX16 = $2B ; i.e. $60 = Slot 6
P5.TrackHave = $40
P5.WantTrack = $41 ;
@ -427,7 +427,7 @@ but I'll be nice guy and provide a fully documented disassembly:
0863:85 3D STA P5.SecWant ;
0865:B9 CE 08 LDA DestPage,Y ;
0868:F0 05 BEQ NextSector ;v $086F Never read into Zero Page!
086A:85 27 STA P5.Buff+1 ; Tell P5 PROM where in mem we want to load
086A:85 27 STA P5.Dest+1 ; Tell P5 PROM where in mem we want to load
CallReadSec: ; *** SELF-MODIFIED @ $084F
086C:20 5C 00 JSR $005C ; CALL P5 PROM Read Sector @ $C65C
@ -526,7 +526,7 @@ it comes from the P5 PROM ReadSector routine @ $C65C.
On my //e it looks this:
```asm
P5.Buff = $26 ; 16-bit pointer to dest
P5.Dest = $26 ; 16-bit pointer to dest
P5.SlotX16 = $2B ; i.e. $60 = Slot 6
; Magic Numbers "disk nisk nibbles"
@ -599,7 +599,7 @@ On my //e it looks this:
C6BF:10 FB BPL ^14 ;^ $C6BC
C6C1:59 D6 02 EOR $36C-$96,Y
C6C4:A4 3C LDY P5.Nibs
C6C6:91 26 STA (P5.Buff),Y
C6C6:91 26 STA (P5.Dest),Y
C6C8:C8 INY
C6C9:D0 EF BNE ^13 ;^ $C6BA
C6CB:BC 8C C0 ^15 LDY DRIVE_DATA,X
@ -611,16 +611,16 @@ On my //e it looks this:
C6D7:A2 56 ^17 LDX #$56
C6D9:CA ^18 DEX
C6DA:30 FB BMI ^17 ; $C6D7
C6DC:B1 26 LDA (P5.Buff),Y
C6DC:B1 26 LDA (P5.Dest),Y
C6DE:5E 00 03 LSR $0300,X ; $0300[ $00 .. $55 ]
C6E1:2A ROL
C6E2:5E 00 03 LSR $0300,X ; $0300[ $00 .. $55 ]
C6E5:2A ROL
C6E6:91 26 STA (P5.Buff),Y
C6E6:91 26 STA (P5.Dest),Y
C6E8:C8 INY
C6E9:D0 EE BNE ^18 ;^ $C6D9
C6EB:E6 27 INC P5.Buff+1 ; DestAddr += $0100
C6EB:E6 27 INC P5.Dest+1 ; DestAddr += $0100
C6ED:E6 3D INC P5.SecWant ; SectorsLoaded++
C6EF:A5 3D LDA P5.SecWant ; also alias for NextSectorToLoad
C6F1:CD 00 08 CMP P5.SecTotal ; SectorsLoaded <= SectorsTotal ?