[comp.sys.atari.st] Misc. questions---16Mhz answer

Friesen@PCO-MULTICS.HBI.HONEYWELL.COM (05/11/89)

Chuck Rickard asks about the 16MHz upgrade for the ST:

It's from FaST technologies, and it does what it says.  Previously
released upgrades only increased the speeds a small amount, but this one
increases it to a full 16MHz because it has caching.  It really works, I
saw it run Flight Simulator II, and it refreshed the screen without
hardly any delay at all!  It is compatible with the Spectre and PC
Ditto.  For installation, you must remove the 68000, and place the
accelorator board (which is the same size as the 68000) under a new
16MHz 68000.  The above were quotes from the sales person.  One thing I
must point out is that while I was there, a man came up and wanted to
run a Fractal program he had written (not compiled) in Fourth.  The
program would not run (I cannot remember the error), but this makes it
seem as if there may be incompatability problems.

There are other 16MHz upgrades, but the spolesperson said that none of
them use caching, so they do not increase the speed to a full 16MHz as
this one is supposed to.


Aric Friesen

Addresses:

Genie:  A.FRIESEN

ARPA:  Friesen%PCO@BCO-MULTICS.ARPA

"Hypnotism; the programming language for people."

dyer@math.lsa.umich.edu (Jon Brode) (05/11/89)

Is this 16mhz upgrade switchable between 16mhz mode and 8mhz/no-caching
mode? I hope so. I have enough trouble playing video games at 8mhz...

Jon Brode  --  dyer@math.lsa.umich.edu
  Terminator Atari Archive Moderator

lharris@gpu.utcs.utoronto.ca (Leonard Harris) (05/12/89)

The main problem with caching is compatibility - a lot of st software
will simply not run on a cached machine.
/leonard

gl8f@bessel.acc.Virginia.EDU (Greg Lindahl) (05/12/89)

In article <1989May11.204205.26151@gpu.utcs.utoronto.ca> lharris@gpu.utcs.UUCP (Leonard Harris) writes:

> The main problem with caching is compatibility - a lot of st software
> will simply not run on a cached machine.

This depends on the cache. PC Klones that have caches must allow self-modifying
code, because apparently lots of PC programs are self-modifying. 68000 programs
aren't supposed to be; if they are, you have to fiddle with the cache when you
try to run on a 68020. Companies with code that won't run on the TT will be
scrambling to fix it, if the TT is ever released.

I'd like more details on how the cache is implemented, and some performance
numbers for all the speedup boards. Even a non-cached board should speed FP
because software FP involves a lot of integer multiplies and divides.

------
Greg Lindahl       |  Welcome to Mars, Earthling. We Martians don't like
gl8f@virginia.edu  |  illegal aliens, so we'll just have to deport you.