Completed in 1969, the FACOM 608B and FACOM 608K were magnetic tape units for Fujitsu's small systems. Half reels were used to equip a single cabinet with two tape decks. These units were developed based on the FACOM 606A magnetic tape unit for small systems, and allowed exchange of data between Fujitsu's leading FACOM 603 Series of magnetic tape units and IBM equipment.
In September 1975, Fujitsu developed the FACOM 612A and 612B as successors of the FACOM 608K. These new models improved performance by increasing recording density to 1600RPI, using full-size reels, and reducing rewind time.
| (For reference) FACOM 606A |
FACOM 608B | FACOM 608K | FACOM 612A/B | |
|---|---|---|---|---|
| Completion date | 1966 | 1969 | September 1975 | |
| Number of drive decks | 1deck/unit | 2decks/unit | ||
| Tape used | Full reel | Half reel (1,200 feet) | Full reel | |
| Recording density(RPI) | 556/333 (*1) | 800/556 | 800 | 1600/(800) (*2) |
| Tape speed | 45inch/s | 27inch/s (0.69m/s) | ||
| Rewind time | 5.5min | 3min(Half reel) | 3min(Full reel) | |
| Data transfer speed | 25/15 Kdigit/s | 21.6/15 KB/s | 21.6 KB/s | 43.2(21.6) KB/s (*2) |
| Recording format | NRZI | PE/(NRZI) (*2) | ||
| Number of tracks | 7 | 9 | ||
| Tape drive system | Swinging single capstan system | Single capstan /vacuum column system | ||
| Main connected systems | FACOM 230-20/30 | FACOM 230-15, FACOM R | FACOM 230-25/35 | FACOM 230-28S/28/38 FACOM M-130/140 |
*1:333RPI was for compatibility with the FACOM 602 magnetic tape unit, and was read only.
*2:Items in parentheses are for the right side deck of the FACOM 612B.
