TU81

From Computer History Wiki
Jump to: navigation, search



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
A TU81

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.