DR11-B parallel interface
The DR11-B was a parallel interface for the UNIBUS which used DMA to transfer data.
Implementation
It was constructed from a number of smaller Flip Chips which were installed in custom 4-slot system unit backplane. The extant DR11-B documentation does not show either the modules used in the DR11-B, or their locations in the backplane.
The modules are:
- M112 - 10 x 2-input NOR gates
- M113 - 10 x 2-input NAND gates
- M116 - 6 x 4-input NOR gates
- M205 - 5 x 'D' flip flops
- 2 x M208 - 8-bit buffer / shift-register
- M239 - 3 x 4-bit counter/register
- 2 x M611 - High speed power inverters
- M796 - UNIBUS Master Control
- M7821 - Interrupt Control
- M7219 - Bus Interface
The M239's are used to hold the Status and Command Register.
The M7219 is a quad card; the others are all single. (The M796 and M7821 are extended length; the others are all standard length.)
Board locations (as seen from the board insertion side of the backplane, not the wire-wrap pin side, as it common in DEC documentation) are:
| Connector | ||||||
|---|---|---|---|---|---|---|
| Slot | A | B | C | D | E | F |
| 1 | UNIBUS In | M7219 Bus Interface | ||||
| 2 | Test board | M208 | M208 | M7821 | M796 | |
| 3 | Power connector | M205 | M611 | M611 | M112 | M113 |
| 4 | UNIBUS Out | User connector | M116 | M239 | ||
Connection to the user device is via either a pair of M957 Split-Lug Cable boards, or via an M9760 (dual) Twisted Pair Cable Connector board. The M9680 (dual) board is a loopback test board, which can be used in place of the user connection board(s).
