Happy Holidays from the KIM-1

kim-1-hh.asm

TIMERCNT = $df
TIMERMCNT = $1

SAD       = $1740
PADD      = SAD+1
SBD       = SAD+2
CLK1T     = $1704
CLK8T     = CLK1T+1
CLK64T    = CLK1T+2
CLK1024T  = CLK1T+3
CLKRDT    = CLK1024T

MSGPTR    = $00
TIMERMVAL = $02

* = $0200
  lda #$7f
  sta PADD
  lda #<MSG
  sta MSGPTR
  lda #>MSG
  sta MSGPTR+1
  lda #TIMERCNT
  sta CLK1024T
  lda #TIMERMCNT
  sta TIMERMVAL
loop:
  ldy #$05
- lda #$00
  sta SAD
  lda DIGIT,y
  sta SBD
  lda (MSGPTR),y
  sta SAD
  ldx #$7f
  dex
  bne *-1
  dey
  bpl -
  lda CLKRDT
  bpl loop
  lda #TIMERCNT
  sta CLK1024T
  dec TIMERMVAL
  bne loop
  lda #TIMERMCNT
  sta TIMERMVAL
  inc MSGPTR
  lda MSGPTR
  cmp #<EOM
  bne loop
  lda #<MSG
  sta MSGPTR
  jmp loop

DIGIT:
  !byte $09, $0b, $0d, $0f, $11, $13
MSG:
  !byte $f6, $f7, $f3, $f3, $ee, $00, $f6, $bf, $b8, $86, $de, $f7, $ee, $ed, $00, $00, $00
EOM:
  !byte $f6, $f7, $f3, $f3, $ee