Here is simple counter code I've made. It just counts from 0 to 99. But it is far from perfection.

Code:
marcato:
tato=0
FOR KAKO=0 TO 99
XAXO=KAKO DIG 0
high latch 'enable write ones
low latch2 'disable write tens
gosub decoder 'display ones
if xaxo=0 and kako dig 1<>0 then 'if count is above 10
low latch 'disable ones
high latch2 'enable tens
'tato=tato+1
xaxo=kako dig 1
gosub decoder
xaxo=0
endif

if xaxo=0 and kako dig 1=0 then     'reset leading 0
low latch
high latch2
xaxo=0
gosub decoder
endif

PAUSE 300
NEXT 
goto marcato
END

decoder:
IF XAXO=0 THEN GOSUB ZERO 
IF XAXO=1 THEN GOSUB ONE
IF XAXO=2 THEN GOSUB TWO
IF XAXO=3 THEN GOSUB THREE
IF XAXO=4 THEN GOSUB FOUR
IF XAXO=5 THEN GOSUB FIVE
IF XAXO=6 THEN GOSUB SIX
IF XAXO=7 THEN GOSUB SEVEN
IF XAXO=8 THEN GOSUB EIGHT
IF XAXO=9 THEN GOSUB NINE
return

ZERO:
LOW A: LOW B: LOW C: LOW D
RETURN
ONE:
HIGH A: LOW B: LOW C: LOW D
RETURN
TWO:
LOW A: HIGH B: LOW C: LOW D
RETURN
THREE:
HIGH A: HIGH B: LOW C: LOW D
RETURN
FOUR:
HIGH C: LOW A: LOW B: LOW D
RETURN
FIVE:
HIGH C: HIGH A: LOW B: LOW D
RETURN
SIX:
HIGH C: HIGH B: LOW A: LOW D
RETURN
SEVEN:
HIGH A: HIGH B: HIGH C: LOW D
RETURN
EIGHT:
HIGH D: LOW A: LOW B: LOW C
RETURN
NINE:
HIGH D: HIGH A: LOW B: LOW C
RETURN