Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!uoft02!desire!cse0421
From: cse0421@desire.wright.edu
Newsgroups: comp.sys.zenith
Subject: Re: EMS Addition to a Z-158
Message-ID: <401.25e1121f@desire.wright.edu>
Date: 20 Feb 90 14:47:11 GMT
References: <1370@darkstar.ucsc.edu>
Distribution: na
Lines: 35

In article <1370@darkstar.ucsc.edu>, banshee@ucscb.UCSC.EDU (Wailin Through The Nets) writes:
> 	I have just attempted to add 256K to my Z-158 as expanded memory.
> 	I have 640K of system RAM and added the new RAM to bank 3.  
> 	However, my playing with the dip switches in sw401 have not been at
> 	all productive.  In particular, #10 on hangs my system with the red
> 	RAM LED on.  I've adjusted the other switches to represent my 640K
> 	and that I have EMS installed to no avail.
> 
> 	Someone out there must have done this.  Zenith's (awful) manuals
> 	keep referring to the 'EMS Upgrade Option' -- do I (gack) need a
> 	logic ROM somewhere?  No diags programs came with my original
> 	setup.  Please respond by Email, I will post if there is sufficient
> 	interest.  Sketches of correct DIP settings would be appreciated.
> 
> 				Thanks in advance.
> 
> 	John M Vinopal	banshee@ucscb.UCSC.EDU	ucbvax!ucscb!banshee
> 			banshee@ucscb.BITNET

John...

Are you sure you have a 158?  The 158 never had an upgrade from Zenith to add
EMS memory.  The 159 on the other hand does.  There is a PAL required to put
EMS memory in a 159.  If you look on your memory board down in the bottom
center of the board, if you see a metal jumper plug stuck in a chip socket
then your computer does not have the PAL in order to handle the EMS memory.
This PAL can be obtained from your local Zenith dealer.

When you install the PAL a couple of switches have to be changed in order for
the computer to see the memory.  I don't have my book here with me or I would
tell you which ones.

			Hope it helps....

				John Wolf