TU81 Streaming Tape Unit
From Computer History Wiki
| TU81 | |
| Manufacturer: | Digital Equipment Corporation |
|---|---|
| Media: | standard half-inch tape |
| Tape density: | 1600 bpi (PE), 6250 bpi (GCR) |
| Tape speed: | 75 inch/sec (high speed streaming mode) or 25 inch/sec (start/stop mode or low-speed streaming mode) |
| Year Introduced: | 1984/1985 |
Big 9-track tape-drives for heavy backup duties.
The TU81 servo/control module uses a Motorola 6802 processor, a variant of the 6800 with 128 bytes of internal RAM and an internal clock oscillator. There is also a 6821 Parallel Interface Adapter chip used for communication between the Servo/Control microprocessor and the Formatter Write microprocessor (on a different board).
Two 6840 Programmable Counter / Programmable Timer Module chips are used to count servo tachs.
The firmware is stored in two ROM chips.
