Re: LF: lots of stuff, mem expander


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Re: LF: lots of stuff, mem expander



At 03:24 PM 7/5/97 -0400, you wrote:
>i have been looking at Mel Tsaiev  page yesterday evening: i discovered that
>someone had finally came through the 92 communication port. It seems that a
>mem expander is not far for the 92... As i haven' t much access to the
>internet, i havn' t  had time to gather info on this: could those who know
>develop this and answer with more precise info ? 

Yes, as you read it is possible to directly access the TI-92's Link Port.
Bryan Turner was the one who figured this out. There are documents in the
works on how to do this. This discovery makes a 92 expander fully possible,
both with Mel Tsai's existing design and a few different designs that are
slowly surfacing.  The expander driver for the TI-92 and the existing
exapander design is being developed.

>now: programming stuff on the sine lib: i think the major pb is that i did
>this: 
>divu D4, D3 
>then , some lines later, 
>divu D4,D3 again: i hadn' thought about the rest of the division which is
>stored in the upper 16 bits... 

This should not cause problems as the default datalength (if you don't put
.b, .l, or .w after an instruction) is .w, so the upper 16 bits are ignored
when you simply put 'divu'

>Thus, i tried to put between these lines : 
>lsl   #8,D3
>lsl   #8,D3
>lsr   #8,D3
>lsr   #8,D3
>but this doesn' t work: the D3 reg is empty after this...

hmm, this will shift d3 right 8*4=32 times, zeroing it out completely as
you found.

If you want to clear the upper word of d3, you could

 swap		d3		;swaps the two word sized halves of d3
 clr.w		d3
 swap		d3		;swap them back, the upper word is now clear

or

 and		$FFFF,d3

>so i tried: 
>move.w   D3,-(A7)
>clr D3
>move.w   (A7)+,D3
>it works just as if i had done nothing....

This will simply move d3 onto the stack, clear d3, then move the previous
value of d3 back into d3, doing absolutely nothing (except it looks kinda
neat, all those ()'s and -/+ signs make your code look sorta complex =)

>
>could someone help ?

Well, I don't quite understand what you are asking, so cannot help much,
but if you can clarify what exactly you are trying to do, I will be happy
to help.

Andrew Von Dollen
warn@geocities.com


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