Well I'm doing some experiments with time keeping programmes to incorporate
into my V-pet.
I've been useing two sprites to display the time each one displays
two numbers.
The sprite data is stores like this.
111__111
1_1__1_1
1_1__1_1
111__111
1_1__1_1
1_1__1_1
111__111
So that there's two copies of each number in each data block. Then I use
a series of ands and ors to select which bits from which blocks I want to
make my time numbers.
But I seem to be screwing up somewhere because things arn't quite working
the way I want them to. The minutes display okay, but for the hours I
only get the last 4 bits
It's probably a stupid mistake, but a fresh pair of eyes would help right
now.
Here's an example of my code which generated the data for the display.
----------------------------------------------------------------------------
time ldy #06 ;just load Y ahead of time for #of sprite lines
lda #$3C ;60
sbc MINS ;subtract the clock minutes from 60 to get the
sta RMINS ;real minutes since clock counts down
cmp #$00 ;see if it's 00 minutes
beq min0
cmp #$32 ;see if it's more than 50 minutes
bpl min5
cmp #$28 ;see if it's more than 40 minutes
bpl min4
cmp #$1E ;see if it's more than 30 minutes
bpl min3
cmp #$14 ;see if it's more than 20 minutes
bpl min2
cmp #$0A ;see if it's more than 10 minutes
bpl min1
min0 lda zeros,y ;minutes must be less than 10 so load 00 sprite
and #$F0 ;strip the first 4 bits
sta SPRITEA,y ;store it to sprite A memory
dey
bpl min0 ;get next sprite line
lda #$00 ;less than 10 minutes
jmp minload ;go to where we load the first 4 bits of sprite
min5 lda fives,y ;minutes must be 50+ so load 55 sprite
and #$F0 ;strip 1st four bits
sta SPRITEA,y ;store it to sprite A memory
dey
bpl min5 ;get next sprite line
lda #$32 ;50+ minutes
jmp minload
etc. etc. for min4,3,2,1
minload STA TEMP
LDA RMINS
SBC TEMP
ASL
TAX
LDA numblk,x
sta TEMP
lda numblk+1,x
sta TEMP+1
ldy #$06
msload lda (TEMP),y
and #$0F
ora SPRITEA,y
sta SPRITEA,y
dey
bpl msload
ldy #$06
lda #$18
SBC HOURS
STA RHOURS
beq hour0
cmp #$14
bpl hour2
cmp #$0A
bpl hour1
hour0 lda zeros,y
and $F0
sta SPRITEB,y
dey
bpl hour0
lda #$00
jmp loadhrs
hour1 lda ones,y
and $F0
sta SPRITEB,y
dey
bpl hour1
lda #$0A
jmp loadhrs
hour2 lda twos,y
and $F0
sta SPRITEB,y
dey
bpl hour2
lda #$14
jmp loadhrs
loadhrs STA TEMP
LDA RHOURS
SBC TEMP
asl
tax
lda numblk,x
sta TEMP
lda numblk+1,x
sta TEMP+1
ldy #$06
hsload lda (TEMP),y
and #$0F
ora SPRITEB,y
sta SPRITEB,y
dey
bpl hsload
rts
numblk .word zeros
.word ones
.word twos
.word threes
.word fours
.word fives
.word sixes
.word sevens
.word eights
.word nines
----------------------------------------------------------------------------
As well, I've noticed another little problem with the decreasing clock
counter. Whenever the hour changes, it takes 2 minutes for the minutes
to change from 00 to 01.
Is this something wrong with the clock counter, or is this something in
my display data generator that's causing this?
CRACKERS
(very sleepy and going to bed from hell!!)
--
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