TA78 Magnetic Tape Drive

TA78
Manufacturer:	DEC
Drive Controller(s):	any Hierarchical Storage Controller
Interface Type:	Standard Tape Interconnect
Media:	standard half-inch 9-track tape
Tape density:	1600 bpi, 6250 bpi
Tape speed:	125 inch/sec
Data rate:	781 Kbytes/sec
Rewind speed:	440 ips
Rewind time:	65 secs (2,400 feet)
Power consumption:	3.7 kVA (max)
Size:	60.5"H x 27.5"W x 30"D
Weight:	630 lbs
Year Introduced:	1984

The TA78 Magnetic Tape Drive was an advanced big magnetic tape drive from DEC. It was a TU78 Magnetic Tape Transport fitted with a TS78 tape formatter (instead of a TM78 formatter), which is a Standard Tape Interconnect (STI) controller. The TS78 can be mounted in a TU78 to produce a 'TA78 master'; a master can control three additional TU78 drives, 'TU78 slaves'. The TS78 is dual-ported, and can be connected to two different Hierarchical Storage Controllers.

It used 2400' 0.5" wide magnetic tape on a standard 10-1/2" reel, and supported 9-track operation at 1600 and 6250 BPI. The TA78 supports two data formats: Phase Encoding (PE) or Group Coded Recording (GCR). Bit density is 1600 bits per inch for the PE format and 6250 bits per inch for the GCR format. The drive can read data in forward as well as reverse direction. It provides pneumatic (vacuum) tape loading.

Further reading

• TA78 Magnetic Tape Drive User Guide (EK-0TA78-UG)
• TA78 Magnetic Tape Drive Technical Description Manual (EK-0TA78-TD) - superseded by EK-OTA79-TM-001 (below)
• TA78 Magnetic Tape Drive Maintenance Guide (AA-P673A-TK)
• TA78 Magnetic Tape Drive IPB (EK-OTA78-IP)

None online, apparently

External links

• TA78 - documentation at Bitsavers
  • TA78 Magnetic Tape Drive Service Manual (EK-0TA78-SV-001)
  • TA78 Maintenance Print Set (MP-01614)
• TA79, TU79, TA78, TU78 Magnetic Tape Subsystem Technical Manual (EK-OTA79-TM-001)
• TA78 and TA81 Magnetic Tape Subsystems - brochure