Disk Info Block
In the System16 Info Block, there is
the entry 'Offset to the DiskInfoBlock (Relative to System16's Base Address)' at offset
90, that points to this block. It's a chained structure with information on all diskdrives
accessable to the V2_OS. Each entry is 32bytes long and starts with one byte that holds
the 'DiskNumber'. This is 0 for the first floppy, 80h for the first fixed disk, 81h for
the second fixed disk etc. If this value is 0ffh, this indicates the end of the chain.
Ofs | Size | Description |
0 | 1 | DiskNumber |
1 | 1 | Reserved (for DiskType) |
2 | 2 | Maximum Cylinders |
4 | 1 | Maximum Heads |
5 | 1 | Maximum Sectors |
6 | 1 | DiskIndex in the 'Type Chain', like 'IDE3', or 'FLOPPY2' etc. |
7 | 1 | Reserved |
8 | 8 | Type BIOS, IDE, ATAPI etc. Padded with spaces !!!, left-alligned |
16 | 8 | Serving Module |
24 | 4 | DiskName like 'fd0',0 or 'hdb',0 etc. 0-Terminated |
28 | 4 | Reserved |
This table can be displayed by using the 'disklist' command from the command-prompt.