Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!oliveb!apple!rutgers!att!westmark!dave
From: dave@westmark.UUCP (Dave Levenson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: expanded memory, different BIOS
Message-ID: <1319@westmark.UUCP>
Date: 6 May 89 02:43:22 GMT
References: <1939@ucsfcca.ucsf.edu>
Organization: Westmark, Inc., Warren, NJ, USA
Lines: 13

In article <1939@ucsfcca.ucsf.edu>, oxalis@ccb.ucsf.edu (Michael Sintchak) writes:

> ... It seems I can't
> have only 256k on my motherboard, the machine won't boot.  I was under
> the impression AT's could work on only 256k main memory.


The AT motherboard usually takes 18 256-k dram chips to make 512-k.
If you remove 9 of these, you'll have 256-k, but you're removing
every odd (or even) byte, not the upper half of the 512-k context. 
The CPU expects memory to be 16 bits wide.  There's no way to make
256-k of 16 bit memory (i.e. 128-k 16-bit words) out of 256-k x 1
chips.