KDF 8189 processor board foobared (ebay warning)

Ethan Dicks ethan.dicks at gmail.com
Mon May 22 08:58:20 CDT 2017

On Sun, May 21, 2017 at 6:11 PM, Glen Slick via cctalk
<cctalk at classiccmp.org> wrote:
>> KDJ11-D (M7554) aka PDP-11/53  "All you need to add is a hard drive controller."
>> See: http://home.windstream.net/engdahl/kdj11.htm
> Yeah, a DECserver 500 or 550 version of an M7554 is usually the least
> expensive version to find. Here are some asking $175.00 or make an
> offer.

Glad I got one a while back...

> I picked up a couple of the DECserver 550 version (1.5MB RAM instead
> of 512KB) for closer to $50 each, but that was several years ago.

Indeed.  I'll have to check mine to see if I have an M7554-SC (512KB)
or M7554-SE (1.5MB)  There appear to be a large number of types of
M7554 in the field guide - different handles, different board etches,
different boot ROMs...

> The 11/53 version without the S-handle bracket seem to be a bit less
> common. I managed to also grab one of those on eBay a while ago, maybe
> less than $100 at the time.

Those were usually found in late-model MicroPDP-11s, and not as
plentiful as some types of PDP-11, IME.

I worked with one in Aug, 1988 that was running MUMPS (a customer
wanted our company to bump up their storage - that was an adventure as
neither of us doing the work had ever used MUMPS before, and it was
all menu-driven and nothing like any other PDP-11 OS that we had
encountered before).


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