options for replacing failed small ROMs in PDP-11

Glen Slick glen.slick at gmail.com
Fri Jun 24 23:15:37 CDT 2016

On Fri, Jun 24, 2016 at 4:36 PM, Fritz Mueller <fritzm at fritzm.org> wrote:
> Hi All,
> In bringing up and debugging my PDP 11/45, I found that one of my GRA
> (M8101) spares has a failed ALU subsidiary ROM.  It's a pretty standard
> little 32x8 ROM in a 16-pin DIP, and the truth table is in the 11/45 print
> set.


If you are talking about he ALU CNTL ROM on page 40 of the PDF and the
truth table for it listed on page 48 of the PDF the part is listed as
DM8598-AD, where a DM8598 is a 256-bit (32x8) tri-state bipolar mask

Some substitute T.S. PROMs include the Signetics 82S123, AMD 27S19,
National DM74S288.

My BP Microsystems programmers support the 82S123 and 27S19, but maybe
not the DM74S288.

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