.export htd32
.proc htd32
		HTD_IN = ARGS+0		; 32-bit input
		HTD_OUT = RESULT	; 10-digit output, one digit per ZP-loc

		ldy #0 ;digit position
		:
			; Count digits on position y
			ldx #<-1 ;digit value
			:
				inx
				sec
				lda HTD_IN+0
				sbc table0,y
				sta HTD_IN+0
				lda HTD_IN+1
				sbc table1,y
				sta HTD_IN+1
				lda HTD_IN+2
				sbc table2,y
				sta HTD_IN+2
				lda HTD_IN+3
				sbc table3,y
				sta HTD_IN+3
			bcs :-

			; Rollback underflowed result
			clc
			lda HTD_IN+0
			adc table0,y
			sta HTD_IN+0
			lda HTD_IN+1
			adc table1,y
			sta HTD_IN+1
			lda HTD_IN+2
			adc table2,y
			sta HTD_IN+2
			lda HTD_IN+3
			adc table3,y
			sta HTD_IN+3

			txa
			sta HTD_OUT,y
			iny
			cpy #10
		bne :--

		rts

table0:	.byte <(1000000000>> 0),<(100000000>> 0),<(10000000>> 0),<(1000000>> 0),<(100000>> 0),<(10000>> 0),<(1000>> 0),<(100>> 0),<(10>> 0),<(1>> 0)
table1:	.byte <(1000000000>> 8),<(100000000>> 8),<(10000000>> 8),<(1000000>> 8),<(100000>> 8),<(10000>> 8),<(1000>> 8),<(100>> 8),<(10>> 8),<(1>> 8)
table2:	.byte <(1000000000>>16),<(100000000>>16),<(10000000>>16),<(1000000>>16),<(100000>>16), <(10000>>16),<(1000>>16),<(100>>16),<(10>>16),<(1>>16)
table3:	.byte <(1000000000>>24),<(100000000>>24),<(10000000>>24),<(1000000>>24),<(100000>>24), <(10000>>24),<(1000>>24),<(100>>24),<(10>>24),<(1>>24)
.endproc

.DEFINE blt bcc

scratch=$f0 ; input in scratch+10..scratch+13, output in scratch+0..scratch+9, most significant first


    jmp test


convert:
    lda#0

    ldx#9
initlp:
    sta scratch,x
    dex
    bpl initlp

    ldy#31
bitlp:

    ldx#9
correctionlp:
    lda scratch,x
    cmp#5
    blt noover
    ;carry now set
    adc#128-5-1
    ;carry now clear
    sta scratch,x
noover:
    dex
    bpl correctionlp

    ldx#13
shiftlp:
    rol scratch,x
    dex
    bpl shiftlp

    dey
    bpl bitlp

    rts


test:
    lda#13
    sta $d021
    jsr $e536
    lda#13
    jsr $ffd2
    lda#0
    sta $d021

    ldx#3
cpl:
    lda testv,x
    sta scratch+10,x
    dex 
    bpl cpl
    jsr convert

    ldx#9
codelp:
    lda#48
    ora scratch,x
    sta $040f,x
    dex
    bpl codelp
    rts


testv:
    .byte $49, $96, $02, $d2 ; 1234567890 = 0x499602d2