8bitfiles.net/archives/archives.tar/archives/genie-commodore-file-library/C64-128Toolkit/REU128.SFX/reu.a

Text File | 1992-11-27 | 4.8 KB | 327 lines

  .DEF STASH
  .DEF FETCH
  .DEF SWAP

  .REF C$KERNIN
  .REF C$KERNOUT
  .REF C$105
  .REF C$106

TOADDR   = $02; &$03
TOBANK   = $04
FROMADDR = $05; &$06
FROMBANK = $07
LEN      = $08; &$09

;*     STASH(TO, TOBANK, FROM, FROMBANK, LEN)
;*          CHAR *TO;
;*          INT TOBANK;
;*          CHAR *FROM;
;*          INT FROMBANK;
;*          INT LEN;
STASH
   STA $FB
   LDA #$0A
   LDX #$00
   LDY #$00
   JSR C$105
   JSR ├OMMON╙TART

;*     ╙ET UP TO ACCESS ╔/╧ BLOCK
   JSR ╔╧BLOCK

;*     ╙TORE 'TO' ADDRESS
   LDA TOADDR
   STA $DF04
   LDA TOADDR+1
   STA $DF05

;*     ╙TORE 'FROM' ADDRESS
   LDA FROMADDR
   STA $DF02
   LDA FROMADDR+1
   STA $DF03

;*     ╙TORE 'TO' BANK
   LDA TOBANK
   STA $DF06

;*     ╙TORE LENGTH OF TRANSFER
   LDA LEN
   STA $DF07
   LDA LEN+1
   STA $DF08

;*     ╙AVE OLD CLOCK SPEED
   LDA $D030
   STA CLOCKSPEED

;*     ╙ET CLOCK SPEED TO SLOW
   LDA #0
   STA $D030

;*     ═AKE APPROPRIATE NEW VALUE
   LDX FROMBANK
   JSR ╞IX╥EGS

;*     ┴CTUALLY DO ╥┼├ CALL
   LDX FROMBANK
   LDY #%10010000
   JSR DMAñCALL

;*     ╥ESTORE OLD VALUES
   LDA CLOCKSPEED
   STA $D030
   LDA RAMCONFIG
   STA $D506
   LDA CONFIGSAVE
   STA $FF00

;*     ╬OW THAT WE'RE DONE, GO BACK TO ├
   LDA #$0A
   LDX #$00
   LDY #$00
   JMP C$106

;*     SWAP(TO, TOBANK, FROM, FROMBANK, LEN)
;*          CHAR *TO;
;*          INT TOBANK;
;*          CHAR *FROM;
;*          INT FROMBANK;
;*          INT LEN;
SWAP
   STA $FB
   LDA #$0A
   LDX #$00
   LDY #$00
   JSR C$105
   JSR ├OMMON╙TART

;*     ╙ET UP TO ACCESS ╔/╧ BLOCK
   JSR ╔╧BLOCK

;*     ╙TORE 'TO' ADDRESS
   LDA TOADDR
   STA $DF04
   LDA TOADDR+1
   STA $DF05

;*     ╙TORE 'FROM' ADDRESS
   LDA FROMADDR
   STA $DF02
   LDA FROMADDR+1
   STA $DF03

;*     ╙TORE 'TO' BANK
   LDA TOBANK
   STA $DF06

;*     ╙TORE LENGTH OF TRANSFER
   LDA LEN
   STA $DF07
   LDA LEN+1
   STA $DF08

;*     ╙AVE OLD CLOCK SPEED
   LDA $D030
   STA CLOCKSPEED

;*     ╙ET CLOCK SPEED TO SLOW
   LDA #0
   STA $D030

;*     ═AKE APPROPRIATE NEW VALUE
   LDX FROMBANK
   JSR ╞IX╥EGS

;*     ┴CTUALLY DO ╥┼├ CALL
   LDX FROMBANK
   LDY #%10010010
   JSR DMAñCALL

;*     ╥ESTORE OLD VALUES
   LDA CLOCKSPEED
   STA $D030
   LDA RAMCONFIG
   STA $D506
   LDA CONFIGSAVE
   STA $FF00

;*     ╬OW THAT WE'RE DONE, GO BACK TO ├
   LDA #$0A
   LDX #$00
   LDY #$00
   JMP C$106

;*     FETCH(TO, TOBANK, FROM, FROMBANK, LEN)
;*          CHAR *TO;
;*          INT TOBANK;
;*          CHAR *FROM;
;*          INT FROMBANK;
;*          INT LEN;
FETCH
   STA $FB
   LDA #$0A
   LDX #$00
   LDY #$00
   JSR C$105
   JSR ├OMMON╙TART

;*     ╙ET UP TO ACCESS ╔/╧ BLOCK
   JSR ╔╧BLOCK

;*     ╙TORE 'TO' ADDRESS
   LDA TOADDR
   STA $DF02
   LDA TOADDR+1
   STA $DF03

;*     ╙TORE 'FROM' ADDRESS
   LDA FROMADDR
   STA $DF04
   LDA FROMADDR+1
   STA $DF05

;*     ╙TORE 'TO' BANK
   LDA FROMBANK
   STA $DF06

;*     ╙TORE LENGTH OF TRANSFER
   LDA LEN
   STA $DF07
   LDA LEN+1
   STA $DF08

;*     ╙AVE OLD CLOCK SPEED
   LDA $D030
   STA CLOCKSPEED

;*     ╙ET CLOCK SPEED TO SLOW
   LDA #0
   STA $D030

;*     ═AKE APPROPRIATE NEW VALUE
   LDX TOBANK
   JSR ╞IX╥EGS

;*     ┴CTUALLY DO ╥┼├ CALL
   LDX TOBANK
   LDY #%10010001
   JSR DMAñCALL

;*     ╥ESTORE OLD VALUES
   LDA CLOCKSPEED
   STA $D030
   LDA RAMCONFIG
   STA $D506
   LDA CONFIGSAVE
   STA $FF00

;*     ╬OW THAT WE'RE DONE, GO BACK TO ├
   LDA #$0A
   LDX #$00
   LDY #$00
   JMP C$106

;*
;*** ╓ARIABLES
;*
CLOCKSPEED .BSS 1
TEMP       .BSS 1
RAMCONFIG  .BSS 1
CONFIGSAVE .BSS 1

;*
;*** ╙UBROUTINES
;*

;*     ┴CCESS ╔/╧ BLOCK
╔╧BLOCK
   LDA $FF00
   STA CONFIGSAVE
   AND #%11111110
   STA $FF00
   RTS

;*     ┴LLOW US TO ACCESS ANY BLOCK OF ╥┴═
╞IX╥EGS
   JSR C$KERNIN
   LDX #$FF
   LDY #$6B
   JSR C$KERNOUT
   AND #%01000000
   STA TEMP
   LDA $D506
   STA RAMCONFIG
   AND #%10111111
   ORA TEMP
   STA $D506
   RTS

;*     ├OMMON START CODE
├OMMON╙TART
   LDY #0       ; START AT START OF PARMS
   LDA ($82),┘
   STA TOADDR
   INY
   LDA ($82),Y
   STA TOADDR+1
   INY
   LDA ($82),Y
   STA TOBANK
   INY
   INY
   LDA ($82),Y
   STA FROMADDR
   INY
   LDA ($82),Y
   STA FROMADDR+1
   INY
   LDA ($82),Y
   STA FROMBANK
   INY
   INY
   LDA ($82),Y
   STA LEN
   INY
   LDA ($82),Y
   STA LEN+1
   RTS

;*         ─O ACTUAL ─═┴ CALL
DMAñCALL
   TXA            ; ╙AVE BANK TO USE
   PHA
   TYA            ; ╙AVE ╥┼├ COMMAND BYTE
   PHA
   LDX #5         ; ╞IX UP ─═┴ STUFF TO SET CONFIGURATION CORRECTLY
DMAñLOOP1
   LDA DMAñCHANGE,X
   STA $03F3,X
   DEX
   BPL DMAñLOOP1

   PLA            ; ╥ESTORE ╥┼├ COMMAND BYTE
   TAY
   PLA            ; ╥ESTORE BANK TO USE
   TAX
   JSR C$KERNIN   ; ─O ACTUAL ─═┴ CALL
   LDX #$FF
   LDY #$50
   JMP C$KERNOUT

   LDX #5
DMAñLOOP2         ; ╥ESTORE ─═┴ STUFF TO ORIGINAL VALUES
   LDA DMAñORIG,X
   STA $03F3,X
   DEX
   BPL DMAñLOOP2
   RTS

DMAñCHANGE
   STA $FF00
   STY $DF01
DMAñORIG
   STY $DF01
   STA $FF00