Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!cbatt!ihnp4!ptsfa!lll-lcc!ames!cit-vax!ll-xn!mit-eddie!uw-beaver!tektronix!tekcrl!vice!tekfdi!videovax!stever
From: stever@videovax.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: CLtd 20M hard disk
Message-ID: <4255@videovax.Tek.COM>
Date: Mon, 2-Mar-87 20:48:15 EST
Article-I.D.: videovax.4255
Posted: Mon Mar  2 20:48:15 1987
Date-Received: Thu, 5-Mar-87 20:25:14 EST
References: <383@pttesac.UUCP> <256@mcdsun.UUCP>
Reply-To: stever@videovax.Tek.COM (Steven E. Rice, P.E.)
Organization: Tektronix Television Systems, Beaverton, Oregon
Lines: 34
Keywords: Cltd 20M hard disk troubles
Summary: Something else to try. . .

In article <256@mcdsun.UUCP>, Fred Fish (fnf@mcdsun.UUCP) writes:

[ Fred details some problems he has been having with a hard disk and
  expansion memory, and things he has done to discourage the guru . . . ]

> 	3.	Replace the MC68000P8 with an MC68000L8 (ceramic package,
> 		on theory that it might have better electrical
> 		characteristics or chip might be marginal).

Some additional improvement may be gained by replacing the MC68000L8 with
an MC68000L10 (10 MHz) or even an MC68000L12 (12.5 MHz).  This will get the
addresses out a bit quicker and allow a few more nanoseconds for data to
get back to the processor.

> . . .
 
> ASDG has promised to send me a version of their Minirack which buffers
> the bus at the connector, rather than adding several inches to it internally
> as my current Minirack-C does.  My ultimate solution will probably be to
> sell off all my current hardware and buy a 2000 as soon as they become
> available, unless I decide to jump ship and buy one of the new high end
> Macs due (as rumor has it) to be announced on Monday.

Buffering right at the connector is a *good* idea!  Four or five inches of
additional run length means a round-trip time of over a nanosecond, and
adds another component to the reflections that are bouncing around inside
the box.

Hope Fred doesn't decide to have a Big Mac! [ 8^( ]

					Steve Rice

----------------------------------------------------------------------------
{decvax | hplabs | ihnp4 | uw-beaver}!tektronix!videovax!stever