> > Is it just a fast processor that's slowed down for memory &
> > io accesses, or is it a fast processor with 512K of fast
> > ram mimicing the SAM's RAM for reads? (but not writes).
>
> You've got it right on the 2nd count... same design as when I first came up
> with it at the beginning of '93 at the moment, with an 8Mhz Z80, and 512k
> SRAM... slows down for processor writes and IO...
>
> Of course, the finished version will only slow down for *some* writes...
> And will have an 18-40MHz processor in it :)
>
> Simon
512K of SRAM????!!!!!! Just how much is that going to cost?!
I seem to remember communication on the mailing list last term
that deduced that DRAM would be feasible (and, of course, cheaper)
though it would slower...
When you say slow down for /some/ writes, how do you propose doing
this? The only way I can think of is:
i) using cacheing techniques
ii) Say that the screen can only reside in certain sections of
memory
iii) similar to ii) but copy from fast-ram to sam-ram whenever
the VMPR port is altered (not very elegant).
Another nice way of doing things would be to make your own video
card using VRAMs - just modes 3 and 4.
-Andrew
