Re: A83: Grbuf again


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Re: A83: Grbuf again




In accordance with the prophecy, Scott Dial uttered:

> AHH... I am tired of people wasting 5 bytes! It is in the rom...
> lcd_busy is in the include file!

Yes, it's in the rom and the rom version is compatible with new, faster
versions of the ti-83 (I assume), _BUT_ TI documents that the routine that
causes the needed delay is:

push af
inc hl
dec hl
pop af
ret

together with a call to that routine. Calling the rom routine wastes several
clock cycles, which is why I used my own routine in Ride - The Demo.

However, these lcdbusy routines are not very lcd-driver friendly. Reading
port 10h and checking bit 7 would be the correct procedure, but would of
course be quite slow.

Linus

- --- Linus Akesson ------------------------ http://linusworld.cjb.net --- -


       Those are my principles. If you don't like them I have others.
                                                      -- Groucho Marx




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