Subject: PDP-8 Memory config

From: Guy Sotomayor <[email-masked]>
Date: Thu Jun 26 08:53:09 2003

Hi,

I have a couple of Dataram DR-118 core boards for a PDP-8 (Omnibus). 
Anyone have any information on this (specifically how to jumper it for
the proper addresses).  I *think* it's a 16kx12 but I'm not certain.

Thanks.
-- 

TTFN - Guy

---

From: Lawrence LeMay <[email-masked]>
Date: Fri Jun 27 20:38:17 2003

> the proper addresses).  I *think* it's a 16kx12 but I'm not certain.

Yes, they are 16Kx12. Which means they can fill in 4 of the 8 possible
4K memory fields in the PDP-8/E memory address.

There is a 16 pin DIP plastic box in the middle of the top board, near
the bottom. It looks like an oversized IC chip. If you tape the 'cover'
off of this, you will see the jumper wires. Basically, the 8 connections
on the left correspond to the 8 possible 4K memory field addresses, and
4 wires are connected to the middle 4 connections on the right side,
which correspond to the actual memory on the DR-118.

If you're careful, you can take the top off without pulling the box out of
the socket. if you do pull it out, be careful not to bend the pins.

If you ever want to trade them for something, just let me know. 

-Lawrence LeMay
 [email-masked]