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]
| Tracks | 6 Data, 1 synchronization |
| char/inch | 248 char/inch |
| Words | 6 chars (32 data bits, 1 odd parity bit, 3 end of file bits) |
| word/inch | 41.33 word/inch |
| End of record gap | 0.75 inch - 186 chars - 31 words |
| Tape speed | 75 inch/s |
| Rewind speed | 500 inch/s (average) |
| Transfer rate | 18,750 char/s - 3,125 word/s |
| Start time | 5 ms |
| Stop time | 5 ms |
| Width of tape | 1/2 inch |
| Length of reel | 2,400 ft (730 m) |
| Composition | Mylar 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
- ^ Faust, Daniel (2008). IBM 728 Magnetic Tape Drive (inkjet print of photograph). The Metropolitan Museum of Art.
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This page was last edited on 29 May 2024, at 17:35