It has 9 chips per row. Doesn't that indicate it does have parity? I bet the switches indicate what bank this memory starts at and (maybe) how many banks are installed. Bob On Mon, Nov 7, 2016 at 1:36 PM, Steven Michelsen via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
The card I have is entirely un-marked. Here's a picture.
https://dl.dropboxusercontent.com/u/65762317/forums/ram_ card_for_IBM_5150.jpg
-----Original Message----- From: vcf-midatlantic [mailto:vcf-midatlantic-bounces@lists. vintagecomputerfederation.org] On Behalf Of william degnan via vcf-midatlantic Sent: Monday, November 07, 2016 1:30 PM To: vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> Cc: william degnan <billdegnan@gmail.com> Subject: Re: [vcf-midatlantic] ram card identification?
On Mon, Nov 7, 2016 at 1:20 PM, Neil Cherry via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 11/07/2016 12:07 PM, Steven Michelsen via vcf-midatlantic wrote:
Hmmmm..... six switches.... could that equal 6 banks of 64k? I hate to guess at this.
Highly unlikely, the AST reference page seems to ring a bell.
I see that minuszerodegrees has a page on AST cards with plenty of options
for switches, but which one might represent mine? http://www.minuszerodegrees.net/manuals/AST/Cards/Many%20AST%20cards. txt
Rough guess:
MEMORY INSTALLED ON 6-PAK
6 dips sw. (note that sw7 is NA and that SW8 is parity which your board doesn't have).
See how your current switches match up with the existing board. Assume that it was working but that the memory board may not have the correct initial addressing. I do recall you said it worked when the case was open. This gives us starting point to intelligently guess.
Oddly enough I only owned 1 PC clone that ran DOS. My work machines were Windows (or OS9 & Flex). None were the type of PC clone that would need this board. Although I built dozens of the clones. Those usually the memory on board (3x256KB or 4x256KB). The one DOS machine I had was a Packard Bell and was a bad clone.
Which model is this? A six pak?
b