TU58 DECtape II
| TU58 | |
 TU58 drive (in standalone case) | |
| Manufacturer: | DEC |
|---|---|
| Drive Controller(s): | built in |
| Interface Type: | asynchronous serial line or parallel |
| Media: | DECtape II |
| Tape density: | 800 bpi |
| Tape speed: | 30 ips (read/write) 60 ips (search) |
| Size: | 5.2"H x 13.6"D x 19"W |
| Weight: | 20 lbs |
The TU58 DECtape II magnetic tape drive used the DECtape-II cartridge, which could hold 256KB. A TU58 unit contained one or two drives, but with two, only one could be operated at a time. It was available in both a standalone case (suitable for desktop usage, or mounting in a 19" rack), or as a bare unit (for mounting in some other unit); in either, it required an external source of power (an optional power supply was available with the standalone case).
The TU58 was used in the following computers resp. controllers:
- PDP-11/44 (as console device)
- VT103 (as system & data device)
- PDP-11/03 (as system & data device)
- VAX-11/750 (as console device)
- VAX-11/730 (as console device)
- VAX-11/725 (as console device)
- HSC50 (as load device)
The unit included control electronics, including a microprocessor and firmware; two versions of the control electronics were available. One (the TU58-XB, DEC part number 54-13489) provided an asynchronous serial line interface, for connection to the host computer via a standard serial line device controller; the other (the TU58-XC, part number 54-13491) provided a parallel interface. The former supported both RS-232 and RS-422; the baud rate could be set from 38.4 Kbaud to 150 baud by configuration jumpers.
The TU58 could be accessed using the Radial Serial Protocol (RSP) or the enhanced Modified Radial Serial Protocol (MRSP)
Average access time using random access was 9.3 seconds; maximum was 28. Data was verified by a checksum on each record.
