[comp.sys.tandy] TRSDOS comeback?

usenet@cps3xx.UUCP (Usenet file owner) (03/07/90)

Recently, I was suprised to see that Zilog has introduced a new version
of the venerable-but-quite-functional Z80 processor that runs, you got
it,

  --> 20 Mhz <----

What's worse, it only costs $18 in sample quantity! That's an incredible
price.

The chip is rated at 5 MIPS. That puts it at roughly 5 times faster than
an IBM AT. '286/'286/'486 Real Mode MIPS (i.e. DOS) are very close to 
Z-80 MIPS in terms of work done (not talking about 32-bit protected mode
instructions) so the comparison is pretty fair.

As all my Model I's are sped up, the natural thought was "gee, what
if..." 20 Mhz? Hmm. Think I'd need to replace those 1K x 1 video rams
with some faster parts (80 ns?) and it's likely that very high speeds
will require going to 64K chips (I don't think 20 Mhz signals will make
it out to the E.I. and back!) but still...

Think of it this way. Lots of Model I/IIIs are running 300% speed-ups, 
what's the big difference between 300% and 1000%? #-)

Terry Conklin
conklin@egr.msu.edu
uunet!frith!conklin
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