RE: A83: Grbuf again

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RE: A83: Grbuf again

Hi!

Q1: 
The LCDBusy is defined as:

#define         lcdbusy         delay-interrupt_start+$8484

so, the LCDbusy is an call to 'delay':

delay:  	push    af                      ; produce small delay
for lcd driver
	inc     hl
	dec     hl
	pop     af
	ret

But why a delay? because the TI's Z80 is faster than the LCD-driver: if
you don't include a delay, the LCD get's overloaded and starts
displaying junk (i think)...

So that's th delay thing...

Q2: 
depends on what type of code... some code works the first time, somtimes
its a stupid bug and takes me 1 or just a few times to recompile and
sometimes it's an hard one and takes me a few hours to find out what's
wrong... and how to fix the bug... 

Hope this helped!

grtx,

Sebastiaan Roodenburg
sebastiaan@rimsystems.nl



> hey,
> 
> A while back Jason_K, whom I thank, posted a routine that copies the
> LCD to 
> the GBUF ...
> 
> LCD_To_GBUF:	; credits = Ian Graf
> 	ld hl, Plotsscreen
> 	ld a, $07
> 	call LCDBusy
> 	out ($10), a
> 	ld a, $80
> 	ld d, a
> 
> Read_Loop1:
> 	call LCDBusy
> 	out ($10), a
> 	ld a, $20
> 	call LCDBusy
> 	out ($10), a
> 	call LCDBusy
> 	in a, ($11)
> 	ld bc,12*256+$11
> 
> Read_Loop2:
> 	call LCDBusy
> 	INI
> 	jr nz, Read_Loop2
> 	inc d
> 	ld a,d
> 	cp $BF
> 	jr nz, Read_Loop1
> 	ld a, $05
> 	call LCDBusy
> 	out ($10), a
> 	ret
> 
> I didn't look at it until today and I don't get what the lcdbusy
> stands for
> So I took the complete source of capture 83 by Ian Graf and, due to my
> 
> no-knoledge-about-interrupts don't get it now either...
> 
> Could someone explain it to me because the code is't commented
> enough... (my 
> opinion) I have attached it ...
> And is there another LCD to GBUF routine that someone could post ?
> 
> thanks.
> 
> Q2: For advanced programmers...
> I was wondering, how many times do you have to correct some code you 
> write... I mean, to me it takes me 10 minutes to work up the logical
> suite 
> and write the code and then at least 1 hour of debugging.  And after 1
> hour 
> of work I always come here and ask you for help.... What about you
> what 
> pourcentage of your time do you spend in debugging?
> 
> About the unsubscription thing.... Yes it is possible to unsubscribe
> someone 
> else, just read the infoletter you received when you joined this list
> .... I 
> could post it if you don't have it ....
> the fact that they haven't replied means that thay no longer have
> acces to 
> the list.... until the next time they subscribe.
> 
> thanks
> 
> 
> 
> 
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