PDP-11/20 in Iowa (x3)

Al Kossow aek at bitsavers.org
Mon Mar 27 11:20:40 CDT 2017

On 3/27/17 7:37 AM, Systems Glitch via cctalk wrote:
>> I don't know of MOS memory appearing in 11/20s as built by DEC, but there's no reason against it.

There were 3rd party cards, Monolithic Systems, for example.
The problem with the 11/20 is that hex wide cards don't fit, the fans overlap the unibus jumper area.
If you ever see hex-wide cards with a big notch in one end, they were designed to work in the 11/15 11/20

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