The Victor 9000 / Sirius One was a rather strange old 8086-based machine which used a disk format very reminiscent of the Commodore format; not a coincidence, as Chuck Peddle designed them both. They're 80-track, 512-byte sector GCR disks, with a variable-speed drive and a varying number of sectors per track --- from 19 to 12. Disks can be double-sided, meaning that they can store 1224kB per disk, which was almost unheard of back then. Because the way that the tracks on head 1 are offset from head 0 (this happens with all disks), the speed zone allocation on head 1 differs from head 0...
| Zone | Head 0 tracks | Head 1 tracks | Sectors | Original period (ms) |
|---|---|---|---|---|
| 0 | 0-3 | 19 | 237.9 | |
| 1 | 4-15 | 0-7 | 18 | 224.5 |
| 2 | 16-26 | 8-18 | 17 | 212.2 |
| 3 | 27-37 | 19-29 | 16 | 199.9 |
| 4 | 38-47* | 30-39* | 15 | 187.6 |
| 5 | 48-59 | 40-51 | 14 | 175.3 |
| 6 | 60-70 | 52-62 | 13 | 163.0 |
| 7 | 71-79 | 63-74 | 12 | 149.6 |
| 8 | 75-79 | 11 | 144.0 |
(The Original Period column is the original rotation rate. When used in FluxEngine, the disk always spins at 360 rpm, which corresponds to a rotational period of 166 ms.)
*The Victor 9000 Hardware Reference Manual has a bug in the documentation and lists Zone 4 as ending with track 48 on head 0 and track 40 on head 1. The above table matches observed data on various disks and the assembly code in the boot loader, which ends Zone 4 with track 47 on head 0 and track 39 on Head 1.
FluxEngine can read and write both the single-sided and double-sided variants.
- Format variants:
612: 612kB 80-track DSHD GCR1224: 1224kB 80-track DSHD GCR
To read:
fluxengine read victor9k --612 -s drive:0 -o victor9k.imgfluxengine read victor9k --1224 -s drive:0 -o victor9k.img
To write:
fluxengine write victor9k --612 -d drive:0 -i victor9k.imgfluxengine write victor9k --1224 -d drive:0 -i victor9k.img