DR11-A General Device Interface
The DR11-A General Device Interface was a UNIBUS device controller which provided a pair of 16-bit parallel ports, one input, and one output.
It was a dual format card (M786), along with two standard single-width card FLIP CHIPs, the M105 Address Selector and the M782 Interrupt Control; they used an SPC slot.
Connection to the user's device is via a DEC backplane slot connector on one side of the card, into which two single-width paddle cards plugged.
The DR11-A was replaced by the single-board DR11-C general device interface. The DR11-C is upwardly compatible with the DR11-A for programming, but uses the cheaper and easier to work with Berg connectors.
Contents
[hide]Registers
The device has three control and buffer registers, which can be configured to any three sequential word locations in the I/O page; the first DR11-A is normally configured to addresses 777520-777524:
| Register | Abbreviation | Address |
|---|---|---|
| Control and Status Register | DRCSR | 777520 |
| Output Buffer Register | DROUTBUF | 777522 |
| Input Buffer Register | DRINBUF | 777524 |
In the register contents (below), bits which are read/write or unused are shown in normal font, those which are read-only are in italics.
Status Register (DRCSR)
| REQ B | Unused | REQ A | INT ENB A | INT ENB B | Unused | |||||||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 | |
Output Buffer Register (DROUTBUF)
| OUT15 <-> OUT0 | |||||||||||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 |
Input Buffer Register (INBUF)
| IN15 <-> IN0 | |||||||||||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 |
