Anyone have a M8340 (EAE) schematic rev.D? Or M8341 rev.D sch?

Stephen Lafferty steve at
Wed Mar 4 23:23:42 CST 2015

Hi Folks,

We're trying to get an EAE (extended arithmetic element) board set 
working in a PDP-8/e. It turns out that DEC made changes which render 
M8340 rev.D incompatible with M8341 rev.D. (Both of the boards we have 
are rev.D, sigh.) M8340 rev.D requires at least an M8341 rev.E.

We would like to modify the boards to be compatible but the only 
schematic of M8340 that we've been able to find is rev.F. So it's 
difficult to figure out what changes are needed.

If anyone has an M8340 schematic earlier than rev.F or an M8341 rev.D 
sch, that would be a huge help.

The goal is to get Spacewar! working on the PDP-8/e for the upcoming 
VCFSE show. This version of Spacewar! requires the EAE. We GOTTA get 
Spacewar! working for the PDP-8's 50th! :)  Please help.


PS: The revision letter can be found in the lower right-hand corner of 
the DEC schematics that I have.

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