Re: 20MHz 65C816 (IIGS CPU) in production: used in C= accelerator

[nathan@visi.com (Nathan Mates)]

In article <58sn62$13v6@uni.library.ucla.edu>,
 <pubpc1@library.ucla.edu> wrote:
>We're interested in whether WDC will let us IIGS users have the same
>20MHz part used in the Super64CPU/20.  Of course that accelerator
>won't work in a IIGS.

   I saw posts a year ago or more for ordering 20Mhz 65816s for
ZipGSs.  However, you face rapidly diminishing returns with such a
thing-- past a certain speed (13-14Mhz, from reports), you'll rapidly
run out of cache, and spend all your time diddling around for the 1Mhz
bus of the GS. [And apparently the Zip only has the logic to put out
one byte at a time on the bus; Todd Whitesel said that if they'd spent
the extra brainpower to do a word at a time, a 7Mhz Zip would have
smoked a 12+Mhz TWGS out of the water]

   This C64 accelerator does things right: a 20Mhz microprocessor and
64K of SRAM. That's not cache ram, that's system RAM running at
15-25ns, which is damn fast, and no bottlenecks of the original
motherboard in the way. 

   Of course, this will be the start of YADANA2 [1]. It's all very
nice to listen to, but until someone gets off their *** and actually
does something, it's pointless. Everyone can dream up a system running
at X Mhz; you should be encouraging the folks who can put pencil to
paper (and etchings to boards) via money, etc to actually get
something done. In other words, everyone'd like to be a backseat
driver, but nobody's got the gumption to get in and drive.

Nathan Mates[2]


[1] Yet another daydream about another new Apple II
[2] And I'm pretty much a software only kiddie. However, should
someone actually build it, I'll buy it.
--
<*> Nathan Mates http://www.visi.com/~nathan/      <*>
# What are the facts? Again and again and again-- what are the _facts_?
# Shun wishful thinking, avoid opinion, care not what the neighbors
# think-- what are the facts, and to how many decimal places?  -R.A. Heinlein