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More IRQ handling fixes. Should be correct now!

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Bobbi Webber-Manners 2021-08-16 14:58:05 -04:00
parent a651218346
commit 8c92712dbe
4 changed files with 34 additions and 32 deletions
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BIN
applecorn.po
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38
applecorn.s
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@ -1,8 +1,10 @@
* Load an Acorn BBC Micro ROM in aux memory and
* Provide an environment where it can run
* APPLECORN.S
* (c) Bobbi 2021 GPLv3
*
* Assembled with the Merlin 8 assembler.
* Load an Acorn BBC Micro ROM in aux memory and
* Provide an environment where it can run
*
* Assembled with the Merlin 8 v2.58 assembler on Apple II.
XC ; 65c02
ORG $2000 ; Load addr of loader in main memory
@ -75,13 +77,13 @@ AUXMOS EQU $D000 ; Final location in aux LC
* Called by code running in main mem to invoke a
* routine in aux memory
XF2AUX MAC
SEI ; EXPERIMENT
LDX $C08B ; R/W LC RAM, bank 1
LDX $C08B
LDX #<]1
STX STRTL
LDX #>]1
STX STRTH
SEI ; Disable IRQ before XFER
SEC ; Use aux memory
BIT $FF58 ; Set V: use alt ZP and LC
JMP XFER
@ -90,7 +92,6 @@ XF2AUX MAC
* Called by code running in aux mem to invoke a
* routine in main memory
XF2MAIN MAC
SEI ; Experiment
LDX STRTL
STX STRTBCKL
LDX STRTH
@ -99,6 +100,7 @@ XF2MAIN MAC
STX STRTL
LDX #>]1
STX STRTH
SEI ; Disable IRQ before XFER
TSX
STX $0101 ; Save alt SP
LDX $0100 ; Load main SP into X
@ -109,13 +111,13 @@ XF2MAIN MAC
* Macro called on re-entry to aux memory
ENTAUX MAC
LDX $0101 ; Recover alt SP
TXS
CLI ; Re-enable IRQ after XFER
LDX STRTBCKL
STX STRTL
LDX STRTBCKH
STX STRTH
LDX $0101 ; Recover alt SP
TXS
CLI
EOM
* Macro called on re-entry to main memory
@ -123,7 +125,7 @@ ENTMAIN MAC
TXS ; Main SP already in X
LDX $C081 ; Bank in ROM
LDX $C081
CLI
CLI ; Re-enable IRQ after XFER
EOM
* Enable writing to main memory (for code running in aux)
@ -132,12 +134,28 @@ WRTMAIN MAC
STA $C004 ; Write to main memory
EOM
* Go back to writing to aux (for code runnign in aux)
* Go back to writing to aux (for code running in aux)
WRTAUX MAC
STA $C005 ; Write to aux memory
CLI ; Normal service resumed
EOM
* Manually enable AltZP (for code running in main)
ALTZP MAC
SEI ; Disable IRQ when AltZP on
LDA $C08B ; R/W LC bank 1
LDA $C08B
STA $C009 ; Alt ZP and LC
EOM
* Manually disable AltZP (for code running in main)
MAINZP MAC
STA $C008 ; Main ZP and LC
LDA $C081 ; Bank ROM back in
LDA $C081
CLI ; Turn IRQ back on
EOM
* Code is all included from PUT files below ...
* ... order matters!
PUT LOADER

4
loader.s
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@ -14,10 +14,6 @@ START JSR ROMMENU
JSR SETPRFX
JSR DISCONN
STA $C009 ; Alt ZP on
STZ $9F ; WARMSTRT - set cold!
STA $C008 ; Alt ZP off
JSR OPENFILE ; Open ROM file
BCC :S2
LDX #$00

24
mainmem.s
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@ -88,9 +88,7 @@ RESET TSX
* Copy 512 bytes from BLKBUF to AUXBLK in aux LC
COPYAUXBLK
SEI
LDA $C08B ; R/W LC RAM, bank 1
LDA $C08B
STA $C009 ; Alt ZP (and Alt LC) on
>>> ALTZP ; Alt ZP & Alt LC on
LDY #$00
:L1 LDA BLKBUF,Y
@ -112,9 +110,7 @@ COPYAUXBLK
INY
BRA :L2
:S2 STA $C008 ; Alt ZP off
LDA $C081 ; Bank the ROM back in
LDA $C081
:S2 >>> MAINZP ; Alt ZP off, ROM back in
CLI
RTS
@ -339,9 +335,7 @@ TELL >>> ENTMAIN
DW GMARKPL
:S1 LDX MOSFILE+1 ; Pointer to ZP control block
BCS :ERR
LDA $C08B ; R/W LC RAM, bank 1
LDA $C08B
STA $C009 ; Alt ZP on
>>> ALTZP ; Alt ZP & Alt LC on
LDA GMARKPL+2
STA $00,X
LDA GMARKPL+3
@ -349,21 +343,15 @@ TELL >>> ENTMAIN
LDA GMARKPL+4
STA $02,X
STZ $03,X
STA $C008 ; Alt ZP off
LDA $C081 ; Bank the ROM back in
LDA $C081
>>> MAINZP ; Alt ZP off, ROM back in
:EXIT >>> XF2AUX,OSARGSRET
:ERR LDX MOSFILE+1 ; Address of ZP control block
LDA $C08B
LDA $C08B
STA $C009
>>> ALTZP ; Alt ZP & Alt LC on
STZ $00,X
STZ $01,X
STZ $02,X
STZ $03,X
STZ $C008
LDA $C081
LDA $C081
>>> MAINZP ; Alt ZP off, ROM back in
BRA :EXIT
* ProDOS file handling for MOS OSFILE LOAD call