A83: Re: Using the IY register
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A83: Re: Using the IY register
Yeah, IY is set up by the TI OS upon start-up and is assumed to remain constant -- TI
recommends you don't use it. If you do, you MUST set it back otherwise all hell will break
loose :)...
James.
----- Original Message -----
From: James Vernon <jimbob_v@hotmail.com>
To: <assembly-83@lists.ticalc.org>
Sent: Wednesday, March 15, 2000 2:47 AM
Subject: A83: Using the IY register
>
> G'day guys/gals,
> I just wanted to check something - if you wanted to use the IY register
> for something in your program you would have to do the following:
>
> di ; Disable interrupts so IY can be used
> push iy ; Preserve IY (pointer to system flags)
> {code}
> pop iy
> ei
>
> The "di" and "ei" are required.. correct? I think so, cos not having them
> caused one of bugs in my game I think...
>
> James Vernon
> jimbob_v@hotmail.com
>
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