IBM 728
The IBM 728 magnetic tape drive was used on the SAGE AN/FSQ-7 computer. It was physically similar to the IBM 727, but with significantly different specifications.
This is one of several IBM 7 track tape drives.
| tracks | 6 Data, 1 synchronization |
| char/inch | 248 char/inch |
| words | 6 chars |
| 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 |
| 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 | |
| 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