A86: Re: RAM1 (was FindPixel in 84 cycles)
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A86: Re: RAM1 (was FindPixel in 84 cycles)
On Sun, 10 Aug 1997, Kip Lambel wrote:
> the memory from $8000-$BFFF is used for page flipping on the ti-86.that
> means you can't use the memory as "scratch" for asm programming. if you
We know that. We were talking specifically about RAM page 1, which seems
to be the page that is available by default when AsmPrgms are run. The
detail we're concerned with is whether or not Page 1 is scratch space. So
far no reliable source has commented.
It does seem that no variables are assigned to page 1, yet when I take a
look at it, there are meaningful data there (looks like the deep-recall
list). It could be that page 1 is used as scratch space by the system.
It would certainly make for fast cross-page copies. Here's my guess:
Set $8000-BFFF to RAM page 1, set $4000-7FFF to RAM page N (the source
page), and copy data from page N to page 1. Then set $4000-7FFF to page M
(the destination page) and copy data from page 1 to page M. It would be a
lot faster than flipping pages frequently, and it would explain why no
vars are assigned to RAM1 yet there are recognizable patterns there.
I'm going to try to find evidence for this.
--------
Dan Eble (mailto:eble@cis.ohio-state.edu)
(http://www.cis.ohio-state.edu/~eble)
References: