【Fujitsu】 FACOM 611A Magnetic Tape Unit

The FACOM 611A was a magnetic tape unit from Fujitsu which achieved high density recording and high performance by using a new recording system called GCR (Group Coded Recording). It was completed in 1976, and had the following features:

(1) Using the new GCR recording system, it achieved high-density recording at 6,250RPI and high-speed data transfer at 781 Kbyte/s. (Previously, these speeds were 1,600RPI and 320Kbyte/s.)

(2) A function was added for on-the-fly correction of errors on 1 track during tape reading with the GCR system. Error detection was also improved.

(3) Both reading and writing were possible, even with the previous recording format.

Tape speed for this equipment was 125inch/s, but in the following year (1977), Fujitsu completed their top-performing FACOM 613A which increased tape speed to 200inch/s and achieved a data transfer speed capacity of 1.25Mbyte/s. Also in 1981, Fujitsu completed the compact, inexpensive FACOM 617 and FACOM 618 which had a new operation mode called "streaming mode" suitable for backing up magnetic disks. Data transfer speed of the FACOM 618 in streaming mode was 1.25Mbyte/s—the same performance as the FACOM 613A which had the highest performance at the time—but setup area was reduced to 60% of that of the FACOM 613A. In 1986, Fujitsu completed the FACOM 619 which, even in normal mode, achieved a transfer speed of 1.25Mbyte/s (the same as the FACOM 613A) even though the unit was the same size as the FACOM 618.