View source for TU58 DECtape II

{{Infobox Tape drive
| image = tu58.jpg
| name = TU58
| caption = TU58 drive (in standalone case)
| manufacturer = [[Digital Equipment Corporation|DEC]]
| controller = built in
| interface = [[asynchronous serial line]] or [[parallel]]
| media = [[DECtape II]]
| tape speed = 30 ips (read/write)<br>60 ips (search)
| tape density = 800 bpi
| 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 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 [[EIA RS-232 serial line interface|RS-232]] and [[EIA RS-422 serial line interface|RS-422]]; the [[baud rate]] could be set from 38.4 Kbaud to 150 baud by configuration [[jumper]]s.

Communication with the TU58 used 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.

==Uses==

The TU58 was used in the following computers:

* [[PDP-11/44]] (as [[mass storage]] device for console subsystem)
* [[VT103]] (as system & data device)
* [[PDP-11/03]] (as system & data device)
* [[VAX-11/750]] (as device for console)
* [[VAX-11/730]] (as device for console)
* [[VAX-11/725]] (as device for console)
* [[HSC50 Mass-Storage Controller‎‎|HSC50]] (as load device) 

==Further reading==
	
* ''TU58 Tape Format and Addressing Modes'', [[MicroNote]] #097
* ''TU58 Cabling'', MicroNote #073
* ''Interfacing to the TU58 w/o Break'', MicroNote #086
* ''TU58 Tips'', MicroNote #096
* ''TU58 System Power Problem'', MicroNote #101
* ''Type-in Bootstrap for TU58'', MicroNote #087

==External links==

* [http://www.bitsavers.org/pdf/dec/dectape/tu58/EK-0TU58-UG-004_TU58_DECtape_II_Users_Guide_Dec83.pdf TU58 DECtape II User Guide]
* [http://www.bitsavers.org/pdf/dec/dectape/tu58/EK-0TU58-TM-001_TU58_DECtape_II_Technical_Manual_Sep79.pdf TU58 DECtape II Technical Manual]
* [http://www.bitsavers.org/pdf/dec/dectape/tu58/TU58_Engineering_Specification_Jun78.pdf TU58 Engineering Specification]

[[Category: DEC Tape Drives]]