Post by jusalak on Apr 13, 2023 20:30:01 GMT
I just created an example of Z80 raster programming. Same principles apply as with 6510/8502, that is disable CIA interrupt, enable VIC interrupt, and prepare the interrupt handler. This example uses Z80 IM 2.
The program creates a red stripe in the green border.
main .org $1c01
.byte $0c,$08,$0a,$00,$9e,$37,$31,$38,$31,$00,$00,$00
lda $ff00 ;
pha ; store RAM config to stack
sei ; disable interrupts
lda $ffee
pha
lda $ffef
pha
lda $fff0
pha
lda #$3e ;
sta $ff00 ; select RAM config for Z80
ldx #$00
loop_:
lda #$31 ;prepare z80 IM 2 jump table
sta $3000,x
inx
bne loop_
sta $3100,x
lda #$c3 ;store JP instruction at $3131
sta $3131
lda #$1b ;address lo
sta $3132
lda #$38 ;address hi
sta $3133
lda #$7f ; disable CIA interrupt
sta $dc0d
lda $d01a ;enable raster interrupt
ora #$01
sta $d01a
lda $d011 ;clear raster counter high bit
and #$7f
sta $d011
lda #$c3 ;
sta $ffee ; store JP instruction for Z80 mode start
lda #<z80code ;
sta $ffef ; store lo-byte address
lda #>z80code;
sta $fff0 ; store hi-byte address
lda $d505 ;
pha ; store mode to stack
lda #$b0 ;
sta $d505 ; set Z80 mode - this instruction deactivates 8502 and jumps by Z80 PC to $ffee
nop
nop
pla
sta $d505
pla
sta $fff0
pla
sta $ffef
pla
sta $ffee
pla
sta $ff00
cli
rts
z80code
.byte $01 $00 $02; ld bc,0200h
.byte $11 $00 $38; ld de,3800h
.byte $21; ld hl
.byte <endcode
.byte >endcode
.byte $ED $B0; ldir
.byte $C3 $00 $38; jp 3800h
endcode
The other part
I can't attach the .prg file here but the hex dump is
.org 3800h
3800 31 F0 37 ld sp,37F0h ;set up stack pointer
3803 3E 30 ld a,30h ;set up I register
3805 ED 47 ld i,a
3807 ED 5E im 2 ;set interrupt mode 2
3809 01 20 D0 ld bc,0D020h ;set border color
380C 3E 05 ld a,05h
380E ED 79 out (c),a
3810 01 12 D0 ld bc,0D012h ;set up first interrupt line
3813 3E 64 ld a,64h
3815 ED 79 out (c),a
3817 FB ei ; enable interrupt
3818 00 loop_: nop
3819 18 FD jr loop_ ;do nothing loop
irq1: ;handler 1
381B F5 push af
381C C5 push bc
381D 01 3E 38 ld bc,irq2 ;load handler 2 address to the JP instruction
3820 ED 43 32 31 ld (3132h),bc
3824 01 20 D0 ld bc,0d020h
3827 3E 02 ld a,02h ;red border
3829 ED 79 out (c),a
382B 01 12 D0 ld bc,0d012h ;set lower raster line
382E 3E 84 ld a,84h
3830 ED 79 out (c),a
3832 01 19 D0 ld bc,0d019h ;acknowledge interrupt
3835 3E FF ld a,0ffh
3837 ED 79 out (c),a
3839 C1 pop bc
383A F1 pop af
383B FB ei
383C ED 4D reti
irq2: ;handler2
383E F5 push af
383F C5 push bc
3840 01 1B 38 ld bc,irq1 ;load handler 1 address to the JP instruction
3843 ED 43 32 31 ld (3132h),bc
3847 01 20 D0 ld bc,0d020h
384A 3E 05 ld a,05h ;green border
384C ED 79 out (c),a
384E 01 12 D0 ld bc,0d012h ;set again the upper raster line
3851 3E 64 ld a,64h
3853 ED 79 out (c),a
3855 01 19 D0 ld bc,0d019h ;acknowledge interrupt
3858 3E FF ld a,0ffh
385A ED 79 out (c),a
385C C1 pop bc
385D F1 pop af
385E FB ei
385F ED 4D reti
.endI can't attach the .prg file here but the hex dump is
>01c00 00 0b 1c 0a 00 9e 37 31
>01c08 38 31 00 00 00 ad 00 ff
>01c10 48 78 ad ee ff 48 ad ef
>01c18 ff 48 ad f0 ff 48 a9 3e
>01c20 8d 00 ff a2 00 a9 31 9d
>01c28 00 30 e8 d0 f8 9d 00 31
>01c30 a9 c3 8d 31 31 a9 1b 8d
>01c38 32 31 a9 38 8d 33 31 a9
>01c40 7f 8d 0d dc ad 1a d0 09
>01c48 01 8d 1a d0 ad 11 d0 29
>01c50 7f 8d 11 d0 a9 c3 8d ee
>01c58 ff a9 84 8d ef ff a9 1c
>01c60 8d f0 ff ad 05 d5 48 a9
>01c68 b0 8d 05 d5 ea ea 68 8d
>01c70 05 d5 68 8d f0 ff 68 8d
>01c78 ef ff 68 8d ee ff 68 8d
>01c80 00 ff 58 60 01 00 02 11
>01c88 00 38 21 92 1c ed b0 c3
>01c90 00 38 31 f0 37 3e 30 ed
>01c98 47 ed 5e 01 20 d0 3e 05
>01ca0 ed 79 01 12 d0 3e 64 ed
>01ca8 79 fb 00 18 fd f5 c5 01
>01cb0 3e 38 ed 43 32 31 01 20
>01cb8 d0 3e 02 ed 79 01 12 d0
>01cc0 3e 84 ed 79 01 19 d0 3e
>01cc8 ff ed 79 c1 f1 fb ed 4d
>01cd0 f5 c5 01 1b 38 ed 43 32
>01cd8 31 01 20 d0 3e 05 ed 79
>01ce0 01 12 d0 3e 64 ed 79 01
>01ce8 19 d0 3e ff ed 79 c1 f1
>01cf0 fb ed 4d 00 00 00 00 00
This can be copy-pasted directly to x128 and Z64K; type first MONITOR. When the dump has been pasted, it can be saved by a MONITOR command
S "Z80RASTER",8,01C01,01CF3Works on real hw, VICE and Z64K.
