Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!pikes!bscott
From: bscott@pikes.Colorado.EDU (Ben Scott)
Newsgroups: comp.sys.amiga.tech
Subject: Re: A1000 512K "piggyback RAM" info needed
Summary: I need info too, but on a different subject
Keywords: $c00000 RAM hack piggyback Amiga 1000
Message-ID: <3525@pikes.Colorado.EDU>
Date: 10 Apr 90 07:08:50 GMT
References: <23027@watdragon.waterloo.edu>
Reply-To: bscott@pikes.Colorado.EDU (Ben Scott)
Followup-To: comp.sys.amiga.hardware
Distribution: comp
Organization: University of Colorado, Denver
Lines: 33

In article <23027@watdragon.waterloo.edu> mwandel@tiger.waterloo.edu (Markus Wandel) writes:
>I need to find the circuit which can be used with the Amazing Computing
>piggyback memory hack to map the extra memory at $C00000.  The reason for
>this is weird.  The piggyback memory is in my machine, as is the address
>decoding hack, but I didn't put it there.  I paid someone the cost of the
>chips plus a bit extra to put it in for me.  This guy (hi Mark!) had done
>it so many times, he could have done it blindfolded, and he did a perfect job,
>but I never got a schematic for the extra address decoding.  He didn't have it.

I bought a used, keyboardless Amiga 1000 for $100 (and later got a keyboard for
$25, suprisingly enough) and was informed it had the piggyback hack inside it.
Since it seemed to autoconfig anyway, I accepted this and have a 512K machine 
which seems normal.  However, recently I've been trying to find a 256K expander
to put in since 768K would be nice... anyway, all the ones I've tried in the
little slot have not worked.  Is this just a huge coincidence or is there 
something about the hack that causes the 256K expander to fail?  I know nothing
about the hack itself, never heard of it before I got the 1000, don't know any
specifics like whether it has the address decoder (whatever that is). 

This does belong in c.s.a.hardware and I've directed followups there (I hope).
If anyone can tell me more about how I can add memory cheaply (people seem
to be selling these 256K boxes rather cheaply these days...) I'd appreciate it.

.                           <<<<Infinite K>>>>
 
Well, not quite...


-- 
_______________________________________________________________________________
|                                                                             |
|  Someday, I'm going to make up a clever .sig file like everyone else has... |
|_____________________________________________________________________________|