Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!oliveb!amiga!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: Review of A-1000  to Zorro-II bus expansion box
Message-ID: <6199@cbmvax.UUCP>
Date: 9 Mar 89 22:25:55 GMT
References: <845@amc.UUCP>
Organization: Commodore Technology, West Chester, PA
Lines: 40

in article <845@amc.UUCP>, eric@amc.UUCP (Eric McRae) says:
> Keywords: A-1000, Bus Expansion, Expansion Technologies, Tool Box

> Product:
> Expansion Technologies "Tool Box", Model 2120, SN 5058, Cost $222
> Gives you 2 Zorro-2 slots and a 3 amp power supply in an enclosure
> that plugs directly into the side of your A-1000.

It's about time something reasonable for A1000 expansion came out.  Further
reading points out, however, that this probably isn't a reasonable box.

The size can hardly be avoided, unless they find a different way to mount
the cards.  A Zorro-II runs from front to back on an A2000, making the
card itself longer than an A1000.  Doesn't matter if there's a PC bus or
not.  

> The A-1000 bus is not buffered.  There is one 74F08 (I think it was an
> '08).

Really?  Then this box is no good.  An A1000 SOTS box gets one standard TTL
load per pin, roughly.  A Zorro-II PIC gets two standard TTL loads on most
of it's pins.  So even one card on an unbuffered bus is asking for trouble,
depending on the design.  Two are certainly trouble.  And passing the bus
in this case is another request for problems.  Are you SURE this thing isn't
buffered?  

> Sure enough, +5 was at 6.2V, and +12 was at about 4.4V.  Then I noticed that
> the power supply had 2 trimmers that were both cranked to the stops.

Yow!  Glad to hear things worked out, but there's not excuse for that kind
of thing.

> Eric McRae	 	Applied Microsystems Corporation
				^^^^^^^
				   |
				Good 680x0 emulators.
-- 
Dave Haynie  "The 32 Bit Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
              Amiga -- It's not just a job, it's an obsession