added raster demo

raster.s

@@ -0,0 +1,162 @@
+; Automated test for C64 autostart (use with VICE -debugcart and -limitcycles 
+; options).
+
+.include "defs64.inc"
+
+.forceimport __EXEHDR__
+
+; test-result register exposed by VICE debugging 'cartridge'. Writing to this
+; will cause VICE to exit, with the exit result set to the written value.
+resultRegister = $d7ff
+
+.code
+        ldx #0
+print:  lda msg, x
+        beq done
+        jsr CHROUT
+        inx
+        bne print
+done:
+
+; print end program address
+        lda TXTTAB+1
+        jsr hexout
+        lda TXTTAB
+        jsr hexout
+        lda #'-'
+        jsr CHROUT
+        lda VARTAB+1
+        jsr hexout
+        lda VARTAB
+        jsr hexout
+        lda #13
+        jsr CHROUT
+
+        jsr raster_setup
+exit:
+        lda #0
+        sta resultRegister
+        rts
+
+; print hex A
+hexout:
+        pha
+        lsr
+        lsr
+        lsr
+        lsr
+        jsr hexdig
+        pla
+        and #$0f
+hexdig:
+        cmp #$0a
+        bcc hdsk1
+        adc #$06
+hdsk1:  adc #$30
+        jsr CHROUT
+        rts
+
+.rodata
+msg:    .asciiz "HELLO RASTER WORLD "
+
+; --------------------------
+
+raster_setup:
+        sei
+
+        ldx CINV        ; set new interrupt vector
+        stx raster_cont+1
+        ldy CINV+1
+        sty raster_cont+2
+        ldx #<raster
+        stx CINV
+        ldy #>raster
+        sty CINV+1 
+
+        ldy #0          ; display list index
+        sty T1
+        lda IRQMASK     ; enable VIC raster interrupt
+        ora #1
+        sta IRQMASK
+        lda #150        ; set initial raster line
+        sta RASTER
+        lda SCROLY
+        and #$7f
+        sta SCROLY
+
+        cli
+        rts
+
+raster:
+        asl VICIRQ
+        bcc raster_not
+
+        inc BGCOL0
+
+
+        ldy T1
+raster_exec:   ; execute display list instructions
+        lda raster_list,y   ; instruction value
+        tax
+        iny
+        lda raster_list,y   ; instruction type
+
+raster_chk_poke:
+        cmp #$d0            ; is it a poke?
+        bcc raster_chk_wait ; not a poke instruction
+
+raster_do_poke:
+        sta raster_poke_sta+2 ; set up the address
+        stx raster_poke_sta+1
+
+        iny
+        lda raster_list,y     ; register value
+raster_poke_sta:
+        sta $d020             ; store to register
+        iny
+        sty T1
+        bne raster_exec       ; always
+        brk
+
+raster_chk_wait:
+        cmp #$02
+        bcs raster_do_call ; not a wait instruction
+raster_do_wait:
+        cmp #0
+        beq raster_list_restart
+        stx RASTER
+        iny
+        sty T1
+        bne raster_rti
+        brk
+
+raster_do_call:
+        ; not implemented
+        iny
+        sty T1
+        bne raster_exec
+        brk
+
+raster_list_restart:
+        ldy #0
+        sty T1
+        beq raster_exec       ; always
+
+raster_rti:
+        jmp raster_cont
+
+raster_not:
+        inc EXTCOL
+
+raster_cont:
+        jmp $ea31
+
+raster_list: 
+        .word 100 ; wait for line 100
+        .word $d020 ; set border to color 2
+        .byte 2
+        .word 200 ; wait for line 200
+        .word $d020 ; set border to color 3
+        .byte 2
+        .word 0 ; end
+