Path: utzoo!attcan!uunet!cbmvax!ditto
From: ditto@cbmvax.UUCP (Michael "Ford" Ditto)
Newsgroups: comp.sys.tandy
Subject: Re: RAM Expansion for the Model IV
Summary: RAMs+PAL required
Keywords: M4 RAM expansion pal
Message-ID: <4654@cbmvax.UUCP>
Date: 3 Sep 88 03:12:26 GMT
References: <51640TRM900@PSUVM>
Reply-To: ditto@cbmvax.UUCP (Michael "Ford" Ditto)
Organization: Commodore Technology, West Chester, PA
Lines: 22

In article <51640TRM900@PSUVM> TRM900@PSUVM.BITNET (Tony R. Marasco) writes:
>I remember seeing an article about expanding the Model III's memory
>capacity.  I was wondering if this same technique could be used to upgrade
>the Model IV's memory from 64K to 128K.  Any help would be appreciated.

Tandy was especially sleazy with the Model 4 -- they designed it so that
it required a PAL change to address 128K.  You can order the RAMs and PAL
from Radio Shack, or you can buy a "clone" set from several mail-order-type
places (I even seem to remember that Jameco sells a set).  Or, if you have
access to a PAL programmer I have the PAL equations which I used to make
my own "homebrew" PAL.  I think I used a 16L8 ... I have a hardcopy of the
equations somewhere; I can type it in if someone really wants it.

The RAMs are 4164s, 150ns.  8 of them are standard, 8 more are needed to
have 128K.
-- 
					-=] Ford [=-

	.		.		(In Real Life: Mike Ditto)
.	    :	       ,		ford@kenobi.cts.com
This space under construction,		...!ucsd!elgar!ford
pardon our dust.			ditto@cbmvax.commodore.com