Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!seismo!mimsy!oddjob!hao!noao!mcdsun!fnf
From: fnf@mcdsun.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: CLtd 20M hard disk
Message-ID: <256@mcdsun.UUCP>
Date: Sat, 28-Feb-87 14:10:41 EST
Article-I.D.: mcdsun.256
Posted: Sat Feb 28 14:10:41 1987
Date-Received: Sun, 1-Mar-87 17:20:39 EST
References: <383@pttesac.UUCP>
Reply-To: fnf@mcdsun.UUCP (Fred Fish)
Organization: Motorola Microcomputer Division
Lines: 42
Keywords: Cltd 20M hard disk troubles

In article <383@pttesac.UUCP> vanam@pttesac.UUCP (Marnix van Ammers) writes:
>
>Last Saturday I went to the Commodore computer show in San Francisco.
>While there I saw Cltd's hard disks and was inspired to buy one.  I
>[long description of problems getting disk to work with expansion ram]

I have been going through much the same thing for the last few months with
my CLtd drive and my ASDG Minirack with 4Mb.  So far, here are the fixes
I have tried:

	1.	Replace PALS with faster PALS (you've done this).

	2.	Tie all the ground pins of the PALS together, and to
		a solid board ground (reportedly required on some Amigas
		to get the CSA stuff to work)

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

So far, each "fix" has improved the situation, from initially not being
able to even boot to now being able to sometimes run for a day or so
before guru'ing, which though a considerable improvement, is still
unacceptable.

Both venders have been helpful in attempting to cure the problem.  So
far, I attribute it a poorly designed hardware expansion architecture
with respect to bus noise and reflections.

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.

-Fred
-- 
===========================================================================
Fred Fish  Motorola Computer Division, 3013 S 52nd St, Tempe, Az 85282  USA
{seismo!noao!mcdsun,hplabs!well}!fnf    (602) 438-5976
===========================================================================