Teaser

This is something I started shortly before I got crazy busy last year.

What could I be translating from 6502 to 6803 assembly, and why does it keep saying z80?
😎

<sigh> Only 6000+ lines left to translate.

;--------------------------------------------------------------
; Display sprites.
;
; Input:
;  IX = sprite table
;--------------------------------------------------------------

dspr:
;    lda #(NUMSPR/2)        ; number of sprites to display.
;    sta sprcnt
    ldx        z80_ix
    ldaa     #(NUMSPR/2)        ; number of sprites to display.
    staa     sprcnt
dspr0:
;    ldy #0
;    lda (z80_ix),y         ; get sprite type.
;    cmp #255         ; is it enabled?
;    bne dspr1         ; yes, it needs deleting.
    ldx        z80_ix
    ldaa    0,x            ; get sprite type
    cmpa    #255        ; is it enabled?
    bne        dspr1        ; yes, it needs deleting.
dspr5:
;    ldy #5
;    lda (z80_ix),y         ; new type.
;    cmp #255        ; is it enabled?
;    bne dspr3         ; yes, it needs drawing.
    ldx        z80_ix
    ldaa    5,x            ; new type.
    cmpa    #255        ; is it enabled?
    bne        dspr3         ; yes, it needs drawing.
dspr2:
;    ldy #5
;    lda (z80_ix),y         ; copy new type.
;    ldy #0
;    sta (z80_ix),y
;    ldy #6
;    lda (z80_ix),y         ; copy new image number.
;    ldy #1
;    sta (z80_ix),y
    ldx        z80_ix
    ldd        5,x                ;copy new type 5 and image number 6
    std        0,x                ;> to 0 & 1
;    ldy #7
;    lda (z80_ix),y         ; copy new frame.
;    ldy #2
;    sta (z80_ix),y
    ldaa    7,x            ; copy new frame
    staa    2,x
;    ldy #8
;    lda (z80_ix),y         ; copy new y.
;    ldy #3
;    sta (z80_ix),y
;    ldy #9
;    lda (z80_ix),y         ; copy new x.
;    ldy #4
;    sta (z80_ix),y
    ldd        8,x            ; copy new y & x
    std        3,x
   
;    clc
;    lda z80_x
;    adc #(TABSIZ*2)        ; distance to next odd/even entry.
;    sta z80_x
;    lda z80_i
;    adc #0
;    sta z80_i         ; next sprite.
    ldd        z80_ix
    addd    #(TABSIZ*2)        ; distance to next odd/even entry. next sprite.
    std        z80_ix
   
    dec sprcnt
    bne dspr0            ; repeat for remaining sprites.
    rts
dspr1:
;    ldy #5
;    lda (z80_ix),y         ; type of new sprite.
;    cmp #255        ; is this enabled?
;    bne dspr4         ; yes, display both.
    ldx        z80_ix
    ldaa    5,x            ; type of new sprite
    cmpa    #255        ; is this enabled?
    bne        dspr4        ; yes, display both.
dspr6:
    jsr sspria             ; show single sprite.
    jmp dspr2

; Displaying two sprites.  Don't bother redrawing if nothing has changed.

dspr4:
;    ldy #4
;    lda (z80_ix),y        ; old x.
;    ldy #9
;    cmp (z80_ix),y         ; compare with new value.
;    bne dspr7         ; they differ, need to redraw.
;    ldy #3
;    lda (z80_ix),y        ; old y.
;    ldy #8
;    cmp (z80_ix),y         ; compare against new value.
;    bne dspr7        ; they differ, need to redraw.
    ldx        z80_ix
    ldd        3,x            ; a = old y, b = old x
    cmpa    9,x
    bne        dspr7        ; they differ, need to redraw.
    cmpb    8,x            ; compare against new value.
    bne        dspr7        ; then differ, need to redraw.

;    ldy #2
;    lda (z80_ix),y         ; old frame.
;    ldy #7
;    cmp (z80_ix),y         ; compare against new value.
;    jmp dspr7         ; they differ, need to redraw.
    ldaa    2,x            ; old frame.
    cmpa    7,x            ; compare against new value.
;    jmp    dspr7            ; they differ, need to redraw
    bne        dspr7        ; they differ, need to redraw
   
;    ldy #1
;    lda (z80_ix),y         ; old image.
;    ldy #6
;    cmp (z80_ix),y         ; compare against new value.
;    beq dspr2        ; everything is the same, don't redraw.
    ldaa    1,x            ; old image.
    cmpa    6,x            ; compare against new value.
    beq        dspr2        ; everything is the same, don't redraw.
dspr7:
    jsr sspric         ; delete old sprite, draw new one simultaneously.
;    jmp dspr2
    bra    dspr2
dspr3:
    jsr ssprib         ; show single sprite.
;    jmp dspr2
    bra    dspr2
   
sprcnt:    .byte 0