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prog8/compiler/res/prog8lib/c64/syslib.p8
Irmen de Jong 334f86480a added irq routines for cx16
2021-02-22 00:48:41 +01:00

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; Prog8 definitions for the Commodore-64
; Including memory registers, I/O registers, Basic and Kernal subroutines.
;
; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
;
; indent format: TABS, size=8
%target c64
c64 {
&ubyte TIME_HI = $a0 ; software jiffy clock, hi byte
&ubyte TIME_MID = $a1 ; .. mid byte
&ubyte TIME_LO = $a2 ; .. lo byte. Updated by IRQ every 1/60 sec
&ubyte STATUS = $90 ; kernal status variable for I/O
&ubyte STKEY = $91 ; various keyboard statuses (updated by IRQ)
&ubyte SFDX = $cb ; current key pressed (matrix value) (updated by IRQ)
&ubyte COLOR = $0286 ; cursor color
&ubyte HIBASE = $0288 ; screen base address / 256 (hi-byte of screen memory address)
&uword CINV = $0314 ; IRQ vector
&uword NMI_VEC = $FFFA ; 6502 nmi vector, determined by the kernal if banked in
&uword RESET_VEC = $FFFC ; 6502 reset vector, determined by the kernal if banked in
&uword IRQ_VEC = $FFFE ; 6502 interrupt vector, determined by the kernal if banked in
; the default addresses for the character screen chars and colors
const uword Screen = $0400 ; to have this as an array[40*25] the compiler would have to support array size > 255
const uword Colors = $d800 ; to have this as an array[40*25] the compiler would have to support array size > 255
; the default locations of the 8 sprite pointers (store address of sprite / 64)
&ubyte SPRPTR0 = 2040
&ubyte SPRPTR1 = 2041
&ubyte SPRPTR2 = 2042
&ubyte SPRPTR3 = 2043
&ubyte SPRPTR4 = 2044
&ubyte SPRPTR5 = 2045
&ubyte SPRPTR6 = 2046
&ubyte SPRPTR7 = 2047
&ubyte[8] SPRPTR = 2040 ; the 8 sprite pointers as an array.
; ---- VIC-II 6567/6569/856x registers ----
&ubyte SP0X = $d000
&ubyte SP0Y = $d001
&ubyte SP1X = $d002
&ubyte SP1Y = $d003
&ubyte SP2X = $d004
&ubyte SP2Y = $d005
&ubyte SP3X = $d006
&ubyte SP3Y = $d007
&ubyte SP4X = $d008
&ubyte SP4Y = $d009
&ubyte SP5X = $d00a
&ubyte SP5Y = $d00b
&ubyte SP6X = $d00c
&ubyte SP6Y = $d00d
&ubyte SP7X = $d00e
&ubyte SP7Y = $d00f
&ubyte[16] SPXY = $d000 ; the 8 sprite X and Y registers as an array.
&uword[8] SPXYW = $d000 ; the 8 sprite X and Y registers as a combined xy word array.
&ubyte MSIGX = $d010
&ubyte SCROLY = $d011
&ubyte RASTER = $d012
&ubyte LPENX = $d013
&ubyte LPENY = $d014
&ubyte SPENA = $d015
&ubyte SCROLX = $d016
&ubyte YXPAND = $d017
&ubyte VMCSB = $d018
&ubyte VICIRQ = $d019
&ubyte IREQMASK = $d01a
&ubyte SPBGPR = $d01b
&ubyte SPMC = $d01c
&ubyte XXPAND = $d01d
&ubyte SPSPCL = $d01e
&ubyte SPBGCL = $d01f
&ubyte EXTCOL = $d020 ; border color
&ubyte BGCOL0 = $d021 ; screen color
&ubyte BGCOL1 = $d022
&ubyte BGCOL2 = $d023
&ubyte BGCOL4 = $d024
&ubyte SPMC0 = $d025
&ubyte SPMC1 = $d026
&ubyte SP0COL = $d027
&ubyte SP1COL = $d028
&ubyte SP2COL = $d029
&ubyte SP3COL = $d02a
&ubyte SP4COL = $d02b
&ubyte SP5COL = $d02c
&ubyte SP6COL = $d02d
&ubyte SP7COL = $d02e
&ubyte[8] SPCOL = $d027
; ---- end of VIC-II registers ----
; ---- CIA 6526 1 & 2 registers ----
&ubyte CIA1PRA = $DC00 ; CIA 1 DRA, keyboard column drive (and joystick control port #2)
&ubyte CIA1PRB = $DC01 ; CIA 1 DRB, keyboard row port (and joystick control port #1)
&ubyte CIA1DDRA = $DC02 ; CIA 1 DDRA, keyboard column
&ubyte CIA1DDRB = $DC03 ; CIA 1 DDRB, keyboard row
&ubyte CIA1TAL = $DC04 ; CIA 1 timer A low byte
&ubyte CIA1TAH = $DC05 ; CIA 1 timer A high byte
&ubyte CIA1TBL = $DC06 ; CIA 1 timer B low byte
&ubyte CIA1TBH = $DC07 ; CIA 1 timer B high byte
&ubyte CIA1TOD10 = $DC08 ; time of day, 1/10 sec.
&ubyte CIA1TODSEC = $DC09 ; time of day, seconds
&ubyte CIA1TODMMIN = $DC0A ; time of day, minutes
&ubyte CIA1TODHR = $DC0B ; time of day, hours
&ubyte CIA1SDR = $DC0C ; Serial Data Register
&ubyte CIA1ICR = $DC0D
&ubyte CIA1CRA = $DC0E
&ubyte CIA1CRB = $DC0F
&ubyte CIA2PRA = $DD00 ; CIA 2 DRA, serial port and video address
&ubyte CIA2PRB = $DD01 ; CIA 2 DRB, RS232 port / USERPORT
&ubyte CIA2DDRA = $DD02 ; CIA 2 DDRA, serial port and video address
&ubyte CIA2DDRB = $DD03 ; CIA 2 DDRB, RS232 port / USERPORT
&ubyte CIA2TAL = $DD04 ; CIA 2 timer A low byte
&ubyte CIA2TAH = $DD05 ; CIA 2 timer A high byte
&ubyte CIA2TBL = $DD06 ; CIA 2 timer B low byte
&ubyte CIA2TBH = $DD07 ; CIA 2 timer B high byte
&ubyte CIA2TOD10 = $DD08 ; time of day, 1/10 sec.
&ubyte CIA2TODSEC = $DD09 ; time of day, seconds
&ubyte CIA2TODMIN = $DD0A ; time of day, minutes
&ubyte CIA2TODHR = $DD0B ; time of day, hours
&ubyte CIA2SDR = $DD0C ; Serial Data Register
&ubyte CIA2ICR = $DD0D
&ubyte CIA2CRA = $DD0E
&ubyte CIA2CRB = $DD0F
; ---- end of CIA registers ----
; ---- SID 6581/8580 registers ----
&ubyte FREQLO1 = $D400 ; channel 1 freq lo
&ubyte FREQHI1 = $D401 ; channel 1 freq hi
&uword FREQ1 = $D400 ; channel 1 freq (word)
&ubyte PWLO1 = $D402 ; channel 1 pulse width lo (7-0)
&ubyte PWHI1 = $D403 ; channel 1 pulse width hi (11-8)
&uword PW1 = $D402 ; channel 1 pulse width (word)
&ubyte CR1 = $D404 ; channel 1 voice control register
&ubyte AD1 = $D405 ; channel 1 attack & decay
&ubyte SR1 = $D406 ; channel 1 sustain & release
&ubyte FREQLO2 = $D407 ; channel 2 freq lo
&ubyte FREQHI2 = $D408 ; channel 2 freq hi
&uword FREQ2 = $D407 ; channel 2 freq (word)
&ubyte PWLO2 = $D409 ; channel 2 pulse width lo (7-0)
&ubyte PWHI2 = $D40A ; channel 2 pulse width hi (11-8)
&uword PW2 = $D409 ; channel 2 pulse width (word)
&ubyte CR2 = $D40B ; channel 2 voice control register
&ubyte AD2 = $D40C ; channel 2 attack & decay
&ubyte SR2 = $D40D ; channel 2 sustain & release
&ubyte FREQLO3 = $D40E ; channel 3 freq lo
&ubyte FREQHI3 = $D40F ; channel 3 freq hi
&uword FREQ3 = $D40E ; channel 3 freq (word)
&ubyte PWLO3 = $D410 ; channel 3 pulse width lo (7-0)
&ubyte PWHI3 = $D411 ; channel 3 pulse width hi (11-8)
&uword PW3 = $D410 ; channel 3 pulse width (word)
&ubyte CR3 = $D412 ; channel 3 voice control register
&ubyte AD3 = $D413 ; channel 3 attack & decay
&ubyte SR3 = $D414 ; channel 3 sustain & release
&ubyte FCLO = $D415 ; filter cutoff lo (2-0)
&ubyte FCHI = $D416 ; filter cutoff hi (10-3)
&uword FC = $D415 ; filter cutoff (word)
&ubyte RESFILT = $D417 ; filter resonance and routing
&ubyte MVOL = $D418 ; filter mode and main volume control
&ubyte POTX = $D419 ; potentiometer X
&ubyte POTY = $D41A ; potentiometer Y
&ubyte OSC3 = $D41B ; channel 3 oscillator value read
&ubyte ENV3 = $D41C ; channel 3 envelope value read
; ---- end of SID registers ----
; ---- C64 ROM kernal routines ----
romsub $AB1E = STROUT(uword strptr @ AY) clobbers(A, X, Y) ; print null-terminated string (use txt.print instead)
romsub $E544 = CLEARSCR() clobbers(A,X,Y) ; clear the screen
romsub $E566 = HOMECRSR() clobbers(A,X,Y) ; cursor to top left of screen
romsub $EA31 = IRQDFRT() clobbers(A,X,Y) ; default IRQ routine
romsub $EA81 = IRQDFEND() clobbers(A,X,Y) ; default IRQ end/cleanup
romsub $FF81 = CINT() clobbers(A,X,Y) ; (alias: SCINIT) initialize screen editor and video chip
romsub $FF84 = IOINIT() clobbers(A, X) ; initialize I/O devices (CIA, SID, IRQ)
romsub $FF87 = RAMTAS() clobbers(A,X,Y) ; initialize RAM, tape buffer, screen
romsub $FF8A = RESTOR() clobbers(A,X,Y) ; restore default I/O vectors
romsub $FF8D = VECTOR(uword userptr @ XY, ubyte dir @ Pc) clobbers(A,Y) ; read/set I/O vector table
romsub $FF90 = SETMSG(ubyte value @ A) ; set Kernal message control flag
romsub $FF93 = SECOND(ubyte address @ A) clobbers(A) ; (alias: LSTNSA) send secondary address after LISTEN
romsub $FF96 = TKSA(ubyte address @ A) clobbers(A) ; (alias: TALKSA) send secondary address after TALK
romsub $FF99 = MEMTOP(uword address @ XY, ubyte dir @ Pc) -> uword @ XY ; read/set top of memory pointer
romsub $FF9C = MEMBOT(uword address @ XY, ubyte dir @ Pc) -> uword @ XY ; read/set bottom of memory pointer
romsub $FF9F = SCNKEY() clobbers(A,X,Y) ; scan the keyboard
romsub $FFA2 = SETTMO(ubyte timeout @ A) ; set time-out flag for IEEE bus
romsub $FFA5 = ACPTR() -> ubyte @ A ; (alias: IECIN) input byte from serial bus
romsub $FFA8 = CIOUT(ubyte databyte @ A) ; (alias: IECOUT) output byte to serial bus
romsub $FFAB = UNTLK() clobbers(A) ; command serial bus device to UNTALK
romsub $FFAE = UNLSN() clobbers(A) ; command serial bus device to UNLISTEN
romsub $FFB1 = LISTEN(ubyte device @ A) clobbers(A) ; command serial bus device to LISTEN
romsub $FFB4 = TALK(ubyte device @ A) clobbers(A) ; command serial bus device to TALK
romsub $FFB7 = READST() -> ubyte @ A ; read I/O status word
romsub $FFBA = SETLFS(ubyte logical @ A, ubyte device @ X, ubyte address @ Y) ; set logical file parameters
romsub $FFBD = SETNAM(ubyte namelen @ A, str filename @ XY) ; set filename parameters
romsub $FFC0 = OPEN() clobbers(X,Y) -> ubyte @Pc, ubyte @A ; (via 794 ($31A)) open a logical file
romsub $FFC3 = CLOSE(ubyte logical @ A) clobbers(A,X,Y) ; (via 796 ($31C)) close a logical file
romsub $FFC6 = CHKIN(ubyte logical @ X) clobbers(A,X) -> ubyte @Pc ; (via 798 ($31E)) define an input channel
romsub $FFC9 = CHKOUT(ubyte logical @ X) clobbers(A,X) ; (via 800 ($320)) define an output channel
romsub $FFCC = CLRCHN() clobbers(A,X) ; (via 802 ($322)) restore default devices
romsub $FFCF = CHRIN() clobbers(X, Y) -> ubyte @ A ; (via 804 ($324)) input a character (for keyboard, read a whole line from the screen) A=byte read.
romsub $FFD2 = CHROUT(ubyte char @ A) ; (via 806 ($326)) output a character
romsub $FFD5 = LOAD(ubyte verify @ A, uword address @ XY) -> ubyte @Pc, ubyte @ A, ubyte @ X, ubyte @ Y ; (via 816 ($330)) load from device
romsub $FFD8 = SAVE(ubyte zp_startaddr @ A, uword endaddr @ XY) -> ubyte @ Pc, ubyte @ A ; (via 818 ($332)) save to a device
romsub $FFDB = SETTIM(ubyte low @ A, ubyte middle @ X, ubyte high @ Y) ; set the software clock
romsub $FFDE = RDTIM() -> ubyte @ A, ubyte @ X, ubyte @ Y ; read the software clock
romsub $FFE1 = STOP() clobbers(X) -> ubyte @ Pz, ubyte @ A ; (via 808 ($328)) check the STOP key (and some others in A)
romsub $FFE4 = GETIN() clobbers(X,Y) -> ubyte @Pc, ubyte @ A ; (via 810 ($32A)) get a character
romsub $FFE7 = CLALL() clobbers(A,X) ; (via 812 ($32C)) close all files
romsub $FFEA = UDTIM() clobbers(A,X) ; update the software clock
romsub $FFED = SCREEN() -> ubyte @ X, ubyte @ Y ; read number of screen rows and columns
romsub $FFF0 = PLOT(ubyte col @ Y, ubyte row @ X, ubyte dir @ Pc) -> ubyte @ X, ubyte @ Y ; read/set position of cursor on screen. Use txt.plot for a 'safe' wrapper that preserves X.
romsub $FFF3 = IOBASE() -> uword @ XY ; read base address of I/O devices
; ---- end of C64 ROM kernal routines ----
; ---- utilities -----
asmsub STOP2() -> ubyte @A {
; -- check if STOP key was pressed, returns true if so. More convenient to use than STOP() because that only sets the carry status flag.
%asm {{
txa
pha
jsr c64.STOP
beq +
pla
tax
lda #0
rts
+ pla
tax
lda #1
rts
}}
}
asmsub RDTIM16() -> uword @AY {
; -- like RDTIM() but only returning the lower 16 bits for convenience
%asm {{
stx P8ZP_SCRATCH_REG
jsr c64.RDTIM
pha
txa
tay
pla
ldx P8ZP_SCRATCH_REG
rts
}}
}
; ---- C64 specific system utility routines: ----
asmsub init_system() {
; Initializes the machine to a sane starting state.
; Called automatically by the loader program logic.
; This means that the BASIC, KERNAL and CHARGEN ROMs are banked in,
; the VIC, SID and CIA chips are reset, screen is cleared, and the default IRQ is set.
; Also a different color scheme is chosen to identify ourselves a little.
; Uppercase charset is activated, and all three registers set to 0, status flags cleared.
%asm {{
sei
cld
lda #%00101111
sta $00
lda #%00100111
sta $01
jsr c64.IOINIT
jsr c64.RESTOR
jsr c64.CINT
lda #6
sta c64.EXTCOL
lda #7
sta c64.COLOR
lda #0
sta c64.BGCOL0
jsr disable_runstop_and_charsetswitch
clc
clv
cli
rts
}}
}
asmsub init_system_phase2() {
%asm {{
rts ; no phase 2 steps on the C64
}}
}
asmsub disable_runstop_and_charsetswitch() clobbers(A) {
%asm {{
lda #$80
sta 657 ; disable charset switching
lda #239
sta 808 ; disable run/stop key
rts
}}
}
asmsub set_irq(uword handler @AY, ubyte useKernal @Pc) clobbers(A) {
%asm {{
sta _modified+1
sty _modified+2
lda #0
adc #0
sta _use_kernal
sei
lda #<_irq_handler
sta c64.CINV
lda #>_irq_handler
sta c64.CINV+1
cli
rts
_irq_handler jsr _irq_handler_init
_modified jsr $ffff ; modified
jsr _irq_handler_end
lda _use_kernal
bne +
lda #$ff
sta c64.VICIRQ ; acknowledge raster irq
lda c64.CIA1ICR ; acknowledge CIA1 interrupt
; end irq processing - don't use kernal's irq handling
pla
tay
pla
tax
pla
rti
+ jmp c64.IRQDFRT ; continue with normal kernal irq routine
_use_kernal .byte 0
_irq_handler_init
; save all zp scratch registers and the X register as these might be clobbered by the irq routine
stx IRQ_X_REG
lda P8ZP_SCRATCH_B1
sta IRQ_SCRATCH_ZPB1
lda P8ZP_SCRATCH_REG
sta IRQ_SCRATCH_ZPREG
lda P8ZP_SCRATCH_W1
sta IRQ_SCRATCH_ZPWORD1
lda P8ZP_SCRATCH_W1+1
sta IRQ_SCRATCH_ZPWORD1+1
lda P8ZP_SCRATCH_W2
sta IRQ_SCRATCH_ZPWORD2
lda P8ZP_SCRATCH_W2+1
sta IRQ_SCRATCH_ZPWORD2+1
; stack protector; make sure we don't clobber the top of the evaluation stack
dex
dex
dex
dex
dex
dex
cld
rts
_irq_handler_end
; restore all zp scratch registers and the X register
lda IRQ_SCRATCH_ZPB1
sta P8ZP_SCRATCH_B1
lda IRQ_SCRATCH_ZPREG
sta P8ZP_SCRATCH_REG
lda IRQ_SCRATCH_ZPWORD1
sta P8ZP_SCRATCH_W1
lda IRQ_SCRATCH_ZPWORD1+1
sta P8ZP_SCRATCH_W1+1
lda IRQ_SCRATCH_ZPWORD2
sta P8ZP_SCRATCH_W2
lda IRQ_SCRATCH_ZPWORD2+1
sta P8ZP_SCRATCH_W2+1
ldx IRQ_X_REG
rts
IRQ_X_REG .byte 0
IRQ_SCRATCH_ZPB1 .byte 0
IRQ_SCRATCH_ZPREG .byte 0
IRQ_SCRATCH_ZPWORD1 .word 0
IRQ_SCRATCH_ZPWORD2 .word 0
}}
}
asmsub restore_irq() clobbers(A) {
%asm {{
sei
lda #<c64.IRQDFRT
sta c64.CINV
lda #>c64.IRQDFRT
sta c64.CINV+1
lda #0
sta c64.IREQMASK ; disable raster irq
lda #%10000001
sta c64.CIA1ICR ; restore CIA1 irq
cli
rts
}}
}
asmsub set_rasterirq(uword handler @AY, uword rasterpos @R0, ubyte useKernal @Pc) clobbers(A) {
%asm {{
sta _modified+1
sty _modified+2
lda #0
adc #0
sta set_irq._use_kernal
lda cx16.r0
ldy cx16.r0+1
sei
jsr _setup_raster_irq
lda #<_raster_irq_handler
sta c64.CINV
lda #>_raster_irq_handler
sta c64.CINV+1
cli
rts
_raster_irq_handler
jsr set_irq._irq_handler_init
_modified jsr $ffff ; modified
jsr set_irq._irq_handler_end
lda #$ff
sta c64.VICIRQ ; acknowledge raster irq
lda set_irq._use_kernal
bne +
; end irq processing - don't use kernal's irq handling
pla
tay
pla
tax
pla
rti
+ jmp c64.IRQDFRT ; continue with kernal irq routine
_setup_raster_irq
pha
lda #%01111111
sta c64.CIA1ICR ; "switch off" interrupts signals from cia-1
sta c64.CIA2ICR ; "switch off" interrupts signals from cia-2
and c64.SCROLY
sta c64.SCROLY ; clear most significant bit of raster position
lda c64.CIA1ICR ; ack previous irq
lda c64.CIA2ICR ; ack previous irq
pla
sta c64.RASTER ; set the raster line number where interrupt should occur
cpy #0
beq +
lda c64.SCROLY
ora #%10000000
sta c64.SCROLY ; set most significant bit of raster position
+ lda #%00000001
sta c64.IREQMASK ;enable raster interrupt signals from vic
rts
}}
}
; ---- end of C64 specific system utility routines ----
}
sys {
; ------- lowlevel system routines --------
const ubyte target = 64 ; compilation target specifier. 64 = C64, 16 = CommanderX16.
asmsub reset_system() {
; Soft-reset the system back to Basic prompt.
%asm {{
sei
lda #14
sta $01 ; bank the kernal in
jmp (c64.RESET_VEC)
}}
}
sub wait(uword jiffies) {
; --- wait approximately the given number of jiffies (1/60th seconds)
repeat jiffies {
ubyte jiff = lsb(c64.RDTIM16())
while jiff==lsb(c64.RDTIM16()) {
; wait until 1 jiffy has passed
}
}
}
asmsub memcopy(uword source @R0, uword target @R1, uword count @AY) clobbers(A,X,Y) {
%asm {{
ldx cx16.r0
stx P8ZP_SCRATCH_W1 ; source in ZP
ldx cx16.r0+1
stx P8ZP_SCRATCH_W1+1
ldx cx16.r1
stx P8ZP_SCRATCH_W2 ; target in ZP
ldx cx16.r1+1
stx P8ZP_SCRATCH_W2+1
cpy #0
bne _longcopy
; copy <= 255 bytes
tay
bne _copyshort
rts ; nothing to copy
_copyshort
; decrease source and target pointers so we can simply index by Y
lda P8ZP_SCRATCH_W1
bne +
dec P8ZP_SCRATCH_W1+1
+ dec P8ZP_SCRATCH_W1
lda P8ZP_SCRATCH_W2
bne +
dec P8ZP_SCRATCH_W2+1
+ dec P8ZP_SCRATCH_W2
- lda (P8ZP_SCRATCH_W1),y
sta (P8ZP_SCRATCH_W2),y
dey
bne -
rts
_longcopy
sta P8ZP_SCRATCH_B1 ; lsb(count) = remainder in last page
tya
tax ; x = num pages (1+)
ldy #0
- lda (P8ZP_SCRATCH_W1),y
sta (P8ZP_SCRATCH_W2),y
iny
bne -
inc P8ZP_SCRATCH_W1+1
inc P8ZP_SCRATCH_W2+1
dex
bne -
ldy P8ZP_SCRATCH_B1
bne _copyshort
rts
}}
}
asmsub memset(uword mem @R0, uword numbytes @R1, ubyte value @A) clobbers(A,X,Y) {
%asm {{
ldy cx16.r0
sty P8ZP_SCRATCH_W1
ldy cx16.r0+1
sty P8ZP_SCRATCH_W1+1
ldx cx16.r1
ldy cx16.r1+1
jmp prog8_lib.memset
}}
}
asmsub memsetw(uword mem @R0, uword numwords @R1, uword value @AY) clobbers(A,X,Y) {
%asm {{
ldx cx16.r0
stx P8ZP_SCRATCH_W1
ldx cx16.r0+1
stx P8ZP_SCRATCH_W1+1
ldx cx16.r1
stx P8ZP_SCRATCH_W2
ldx cx16.r1+1
stx P8ZP_SCRATCH_W2+1
jmp prog8_lib.memsetw
}}
}
inline asmsub rsave() {
; save cpu status flag and all registers A, X, Y.
; see http://6502.org/tutorials/register_preservation.html
%asm {{
php
sta P8ZP_SCRATCH_REG
pha
txa
pha
tya
pha
lda P8ZP_SCRATCH_REG
}}
}
inline asmsub rrestore() {
; restore all registers and cpu status flag
%asm {{
pla
tay
pla
tax
pla
plp
}}
}
inline asmsub read_flags() -> ubyte @A {
%asm {{
php
pla
}}
}
inline asmsub clear_carry() {
%asm {{
clc
}}
}
inline asmsub set_carry() {
%asm {{
sec
}}
}
inline asmsub clear_irqd() {
%asm {{
cli
}}
}
inline asmsub set_irqd() {
%asm {{
sei
}}
}
inline asmsub exit(ubyte returnvalue @A) {
; -- immediately exit the program with a return code in the A register
%asm {{
jsr c64.CLRCHN ; reset i/o channels
ldx prog8_lib.orig_stackpointer
txs
rts ; return to original caller
}}
}
inline asmsub progend() -> uword @AY {
%asm {{
lda #<prog8_program_end
ldy #>prog8_program_end
}}
}
}
cx16 {
; the sixteen virtual 16-bit registers that the CX16 has defined in the zeropage
; they are simulated on the C64 as well but their location in memory is different
; (because there's no room for them in the zeropage)
; they are allocated at the bottom of the eval-stack (should be ample space unless
; you're doing insane nesting of expressions...)
&uword r0 = $cf00
&uword r1 = $cf02
&uword r2 = $cf04
&uword r3 = $cf06
&uword r4 = $cf08
&uword r5 = $cf0a
&uword r6 = $cf0c
&uword r7 = $cf0e
&uword r8 = $cf10
&uword r9 = $cf12
&uword r10 = $cf14
&uword r11 = $cf16
&uword r12 = $cf18
&uword r13 = $cf1a
&uword r14 = $cf1c
&uword r15 = $cf1e
}
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