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| IMPORTANT: | The following assumes that your IBM 5170 motherboard is fitted with IBM 5170 BIOS ROM's (i.e. not swapped out for non-IBM ones). Although authors of other BIOS' often mimicked IBM (to maintain IBM compatibility), some authors did not. Example: A Seagate ST-4038 drive is a type 20 on an IBM 5170, but a different type number on certain ALR computers. |
| Cylinder Count |
Head Count |
SPT | WPC | 01/10/84 BIOS |
06/10/85 BIOS |
11/15/85 BIOS |
Comment | |
|---|---|---|---|---|---|---|---|---|
| Type 1 | 306 | 4 | 17 | 128 | Yes | Yes | Yes | |
| Type 2 | 615 | 4 | 17 | 300 | Yes | Yes | Yes | Examples: CMI model 6426, Seagate ST-4026 |
| Type 3 | 615 | 6 | 17 | 300 | Yes | Yes | Yes | |
| Type 4 | 940 | 8 | 17 | 512 | Yes | Yes | Yes | |
| Type 5 | 940 | 6 | 17 | 512 | Yes | Yes | Yes | |
| Type 6 | 615 | 4 | 17 | none | Yes | Yes | Yes | Some Internet sources may show no WPC as "N/A" or "-1" or "65535" |
| Type 7 | 462 | 8 | 17 | 256 | Yes | Yes | Yes | |
| Type 8 | 733 | 5 | 17 | none | Yes | Yes | Yes | Some Internet sources may show no WPC as "N/A" or "-1" or "65535" |
| Type 9 | 900 | 15 | 17 | none | Yes | Yes | Yes | Some Internet sources may show no WPC as "N/A" or "-1" or "65535" |
| Type 10 | 820 | 3 | 17 | none | Yes | Yes | Yes | Some Internet sources may show no WPC as "N/A" or "-1" or "65535" |
| Type 11 | 855 | 5 | 17 | none | Yes | Yes | Yes | Some Internet sources may show no WPC as "N/A" or "-1" or "65535" |
| Type 12 | 855 | 7 | 17 | none | Yes | Yes | Yes | Some Internet sources may show no WPC as "N/A" or "-1" or "65535" |
| Type 13 | 306 | 8 | 17 | 128 | Yes | Yes | Yes | |
| Type 14 | 733 | 7 | 17 | none | Yes | Yes | Yes | Some Internet sources may show no WPC as "N/A" or "-1" or "65535" |
| Type 15 | - | - | - | - | - | - | - | Do not use. More information. |
| Type 16 | 612 | 4 | 17 | 0 (all) | No | Yes | Yes | |
| Type 17 | 977 | 5 | 17 | 300 | No | Yes | Yes | |
| Type 18 | 977 | 7 | 17 | none | No | Yes | Yes | |
| Type 19 | 1024 | 7 | 17 | 512 | No | Yes | Yes | |
| Type 20 | 733 | 5 | 17 | 300 | No | Yes | Yes | Examples: Seagate ST-4038, IBM 0665-38 |
| Type 21 | 733 | 7 | 17 | 300 | No | Yes | Yes | |
| Type 22 | 733 | 5 | 17 | 300 | No | Yes | Yes | |
| Type 23 | 306 | 4 | 17 | 0 (all) | No | No | Yes |