IBM 728

The IBM 728 was an IBM 7 series magnetic tape drive. It was used on the SAGE AN/FSQ-7 computer. It was physically similar to the IBM 727, but with significantly different specifications.[1]

Tracks6 Data, 1 synchronization
char/inch248 char/inch
Words6 chars (32 data bits, 1 odd parity bit, 3 end of file bits)
word/inch41.33 word/inch
End of record gap0.75 inch - 186 chars - 31 words
Tape speed75 inch/s
Rewind speed500 inch/s (average)
Transfer rate18,750 char/s - 3,125 word/s
Start time5 ms
Stop time5 ms
Width of tape1/2 inch
Length of reel2,400 ft (730 m)
CompositionMylar or cellulose acetate base
 Tape Word Bit Positions -----------------------------> Tape travel LS L6 L12 R2 R8 R14 L1 L7 L13 R3 R9 R15 L2 L8 L14 R4 R10 P SYN SYN SYN SYN SYN SYN L3 L9 L15 R5 R11 EOF L4 L10 RS R6 R12 EOF L5 L11 R1 R7 R13 EOF -----------------------------> Tape travel

References

  1. ^ Faust, Daniel (2008). IBM 728 Magnetic Tape Drive (inkjet print of photograph). The Metropolitan Museum of Art.
Retrieved from "https://en.wikipedia.org/w/index.php?title=IBM_728&oldid=1226284020"