Unibus

Available on the old Digital PDP-11. The Unibus signals described in the PDP-11 bus handbook on the A and B connectors are used only for “Modified Unibus Devices” such as bus extenders, terminators and repeaters. Notably the type “2” signals only appear on one pin each. This is O.K on the A and B connectors because each bus segment has a bus in connector at one end and a bus out at the other and the type “2” signals are broken up when they run through the C,D,E and F connectors. Unibus boards that use the C,D,E, and F connectors are called “Small Peripheral Controllers”. Hex boards plug into the A and B connectors as well but do not pick up any signals from them (including power or ground.)

A, B connectors pinouts

     +------------//--------+   +------------//--------+ 
     |AA1 AB1 AC1 // AU1 AV1|   |BA1 BB1 BC1 // BU1 BV1| 
     |AA2 AB2 AC2 // AU2 AV2|   |BA2 BB2 BC2 // BU2 BV2| 
     +------------//--------+   +------------//--------+ 

2 x 36 EDGE FEMALE at the backplane

2 x 36 EDGE MALE at the cards/modules

C, D, E and F connectors pinouts

Unknow connector

References

Category:Buses Connectors