PDP-11/20 vd one that just says pdp 11 what are the date differences?? OEM?

william degnan billdegnan at gmail.com
Mon Feb 22 07:08:20 CST 2016

> This is a known 'artifact' in PDP-11 history. DEC originally used the /10
> designation for a cost-reduced 11/20. They never produced any, AFAIK - I'm
> pretty sure (without checking) that machine was re-labelled the /15, and
> those
> _do_ exist (I used one BITD).
> According to DEC documentation, the /15 has a KC11 processor, not the KA11
> of
> the /20 (although I've never been able to find out much about the KC11 - I
> suspect it was a slightly modified KA11); the main functional difference
> listed is that it only supports one level of interrupt, not four;
> power-fail
> re-start is also optional, not standard.
> I have this bit set that both the /15 and /20 could be had with the
> 'simple'
> front console, that that wasn't the differentiator between them.
> The later /5-/10 pairing does indeed exist - I have one of each. They are
> absolutely identical except for the printing on the faceplate.
>         Noel

The 11/15 was not part of the original launch.  The original PDP 11 /10 and
/20 use the same KA11 processor.  Sources

Original product brochure

Datamation 1/1970 and Electronics Jan 1970:

@ BillDeg:
Web: vintagecomputer.net
Twitter: @billdeg <https://twitter.com/billdeg>
Youtube: @billdeg <https://www.youtube.com/user/billdeg>
Unauthorized Bio <http://www.vintagecomputer.net/readme.cfm>

More information about the cctalk mailing list