Zirias
Registered: Jan 2014
Posts: 48 |
For the score display in 8192, I decided to create something reusable, although I needed it for 32 bit -- this should work for anything up to 128 bit if you adjust the constants, output is right-aligned and padded with spaces (0-padding would simplify it further):
.export numtostring
.exportzp nc_string
.exportzp nc_num
NUMSTRSIZE = $a
NUMSIZE = $4
.zeropage
nc_string: .res NUMSTRSIZE
nc_num: .res NUMSIZE
.code
numtostring:
ldy #NUMSTRSIZE
lda #$0
nts_fillzero: sta nc_string-1,y
dey
bne nts_fillzero
ldy #(NUMSIZE*8)
nts_bcdloop: ldx #(NUMSTRSIZE-2)
nts_addloop: lda nc_string+1,x
cmp #$5
bmi nts_noadd
adc #$2
sta nc_string+1,x
nts_noadd: dex
bpl nts_addloop
asl nc_num
ldx #($ff-NUMSIZE+2)
nts_rol: rol nc_num+NUMSIZE,x
inx
bne nts_rol
ldx #(NUMSTRSIZE-2)
nts_rolloop: lda nc_string+1,x
rol a
cmp #$10
and #$f
sta nc_string+1,x
nts_rolnext: dex
bpl nts_rolloop
dey
bne nts_bcdloop
nts_scan: cpx #(NUMSTRSIZE-1)
beq nts_digits
inx
lda nc_string,x
bne nts_digits
lda #$20
sta nc_string,x
bne nts_scan
nts_digits: lda nc_string,x
ora #$30
sta nc_string,x
inx
cpx #(NUMSTRSIZE)
bne nts_digits
rts
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