[comp.sys.apple] ZIP Chip Question revisited

Bruce_Kahn@maytag.ceo.dg.COM (11/14/87)

 
  After reading Sean K.'s reply about the ZIP Chip and the Siders I 
found myself asking how can this chip access a peripheral card at the 
speed of its INTERNAL clock?  I have 2 hard drives (separate slots) 
and find it interesting that the ZIP Chip can access them faster than 
it would, say, normal memory or ANY cards.  Anyone have a clear 
reason/explaination why/how this is possible?
               Bruce Kahn

mw22+@ANDREW.CMU.EDU (Michael Alan Wertheim) (11/18/87)

Where does it say that the Zip Chip will speed up peripherals?  The Zip Chip,
like the SpeedDemon and TransWarp, probably has to slow itself down to 1 MHz
while accessing peripherals.  (i.e. whenever it sees an address in the $C080
- $C0FF range, it starts executing the next few instructions at slow speed.)


Michael Wertheim
Carnegie Mellon University
Pittsburgh, PA

Arpa: mw22@andrew.cmu.edu
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