[pups] pdp 11/44,unibus configuration and 20mA

lothar felten lothar.felten at gmx.net
Mon Mar 18 07:05:21 AEST 2002

My first unibus-pdp...

I picked up the box this weekend, without any additional equipment or
They also told me is is configured for a 20 mA current loop, but i don't
have a working current loop term. is there a easy way of converting 20mA
current loop to RS-232 ?
I found a posting in classiccmp that says M7090 might be configured for
RS232 or current loop(i don't know if they meant the MUX or the CIM M7090
or both), is there a way to find out without blowing things up ? i do have
a VT420, maybe i can do current loop <-> rs422 ?

i didn't power up the box yet, first i'd like to connect the correct
console and check the configuration. maybe reduce the configuration to
RL11, DEUNA and disk-controller? another problem is the media, i'd like to
install 2.9BSD, but how ? i still hope that one of those unidentified cards
turns out to be a ciphertape-controller (Pertec-interface for my second
cipher F880).

any help, information or link is very welcome.

-- regards, lothar

This is the actual configuration:
<-power supply / frontpanel->

M 7090 -  -  -  -     dual height KD11-Z 11/44 console interface module
 -  -  -  -  -  -     empty (this is where the optional CIS belongs)
------M 7093------    hex height FP11-F 11/44 floating point module
------M 7094------    hex height KD11-Z 11/44 data path module
------M 7095------    hex height KD11-Z 11/44 control module
------M 7096------    hex height KD11-Z 11/44 multifunction module
------M 7097------    hex height KK11-B 11/44 4-Kword cache module
------M 7098------    hex height KD11-Z 11/44 UNIBUS interface
------M 8743------    hex height MS11-PB 1-Mbyte ECC RAM (-BH)
 -  -  -  -  -  -     empty
------M 7486------    hex height UDA52 Controller for SDI disk drives (UDA
------M 7485------    hex height UDA50-A UNIBUS to radial disk interface
------M 7762------    hex height RL11 RL01/02 disk controller
M 9202 ---M 8729--    dual height M9202 / quad height M8729 no info.
M 9202 -  -  -  -     empty (badge says hex SPC slot)
 -  -  -  -  -  -     empty
 -  -  -  -  -  -     empty
 -  -  -  F  -  -     empty, F is a bus grant continuity (single height)
------SC4110------    hex height
------M 7814------    hex height  DZ11-C 8-line 20mA data MUX, 50 to
------M 7792------    hex height  see below
------M 7793------    hex height  see below
 -  -  --Ramtek---    quad height no info
 -  -  -  -  -  -

addition to descriptions:

M7485-YA  UDA50-A UNIBUS to radial disk interface PR board with blasted
M7792 DEUNA port module, UNIBUS to ethernet microprocessor. (1 of 2)
M7793 DEUNA link module, M7792 to ethernet bus line unit. (2 of 2)
i don't have any reliable description for the M8729, i found a with google:
"DRU-11 CA" parallel DMA.
the SC4110 (Emulex) is probably a SMD disk controller, at least the heavy
disk was attached to it.
there are two cards for which i found nothing:
Ramtek 508295/508297 (has a 50 pin connector)
Eikonix 821-015cs (handwritten: 785-283)(has two 50 pin connectors)

while cleaning the box i found three bus grant continuity cards (single
height). it is possible they fell out during transport.
i've read akos varga's unibus basics, but i still can't tell if this is a
valid configuration. i found a badge on top of the box, which says the
M8729 is in a SPC slot and the "second" part of the M9202 is in a hex. SPC

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