IBM Options and Adapters - IBM PC 20MB Fixed Disk Drive Adapter
The IBM Personal Computer 20MB Fixed Disk Drive Adapter is a section of IBM's Technical Reference: Options and Adapters in the Personal Computer Hardware Reference Library, part number 6139790, dated 17 March 1986. It documents the later version of the IBM Fixed Disk Adapter, which supports four drive types selected by switches on the card. The scan is 46 pages.
Contents
[edit | edit source]Page numbers are the section's own.
- Description (pp. 1-2): one or two drives on a daisy-chained cable, DMA transfers, IRQ 5, 11-bit burst error correction by 32-bit ECC, and the warning that the last cylinder is reserved for diagnostics.
- Programming considerations (pp. 3-14), including the table of drive types (p. 3) and their switch settings, the status register, sense bytes and data register.
- Interface (p. 15), connectors (p. 17), logic diagrams (from p. 19, four sheets) and the BIOS listing (from p. 23), which includes the "1701" error message.
| Type | Cylinders | Heads | Write precompensation from | Landing zone | Switches (1-2 for drive 0, 3-4 for drive 1) |
|---|---|---|---|---|---|
| 1 | 306 | 4 | 0 | 306 | On, On |
| 2 | 615 | 4 | 300 | 615 | Off, On |
| 13 | 306 | 8 | 128 | 336 | Off, Off |
| 16 | 612 | 4 | 0 | 663 | On, Off |
What this document does not contain
[edit | edit source]There is no parts list and no fault-finding procedure.
Download: IBM Options and Adapters - IBM PC 20MB Fixed Disk Drive Adapter.pdf