From: Steve Judd (sjudd_at_ffd2.com)
Date: 2003-12-04 07:18:23
Hey Brian,
> By the way, I have a question about SCPU RAM that Maurice Randall couldn't
> help me with. There's that page of "user" RAM in the $Dxxx(?) area, which I
> thought might be handy for an alternative zero page or something. However,
> CMD advised that if you want to write to it, which requires enabling the
> hardware registers, you should do so and then slam the lid shut again as
> fast as possible. If your program doesn't write to the shadow registers,
> why is this necessary? It *seems* overly cautious.
>
> Also, if I may say... that little booklet that comes with the SCPU is pretty
> pathetic. The SCPU could REALLY use a P.R.G., I think.
Heh, well, for what it's worth, according to that booklet, "Enabling the
SuperCPU hardware registers also causes some changes in the Kernal ROM
memory map ($E000-$FFFF). To avoid problems, do not leave the hardware
registers enabled any longer than necessary."
The changes are quite substantial. Try this, for example:
?exp(1)
poke53374,0:?exp(1)
If you write to bank 1 there shouldn't be a problem, but if writing to
bank 0 it's an issue.
For the life of me, I have no idea where my SCPU v2 booklet is, only the
old v1 booklet -- how embarrasing. I did not see these on project 64.
Would some kindly individual mind typing in the register list (or just the
new registers) and sending it to me? :) Thanks!
-Steve
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