Path: utzoo!utgpu!water!watmath!clyde!bellcore!faline!thumper!ulysses!andante!mit-eddie!uw-beaver!tektronix!reed!kamath
From: kamath@reed.UUCP
Newsgroups: comp.sys.apple
Subject: Re: BITNET mail follows (No-Slot clock question)
Message-ID: <9450@reed.UUCP>
Date: 4 Jun 88 18:56:02 GMT
References: <8806011115.aa08363@SMOKE.BRL.ARPA>
Reply-To: kamath@reed.UUCP (Sean Kamath)
Organization: Reed College, Portland OR
Lines: 27

In article <8806011115.aa08363@SMOKE.BRL.ARPA> HEINEKEN@MTUS5.BITNET writes:
>From: Steve King                                     HEINEKEN at MTUS5
>
>Speaking of the no-slot clock, is this messed up in any way by the addidtion
>of an accelerator board or the Zip Chip?  Does it generate its timing
>internally (as would be sensible) or does it just count pulses of the system
>clock (in which case an accelerator might make it run fast...)
>
>                                              --Steve King
>                                                HEINEKEN @ MTUS5

The clock does indeed have it's own oscillator.  All that need be done is
access the data lines with the correct timing and sequence. Since the CPU
thinks it's a ROM (With usually 450 ns access time), this isn't a problem.
I still haven't figured out why it didn't work with my other //e and 65802.

Note that if it *ddid* run off the system clock, it would not make any
difference, as accelerator cards and the chips do their own timing, not muck
with the system clock (which would be a *REALLY* stupid thing to do.).

Sean Kamath

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