17 Nov
2025
17 Nov
'25
8:57 p.m.
On Mon, Nov 17, 2025 at 2:41 PM Mike Katz via cctalk <cctalk(a)classiccmp.org>
wrote:
I have an ST-251 42MB MFM hard disk drive.
The documentation says the drive is 512 bytes per sector. I don't know
if this is fixed (hard sectored) or not.
My problem is my operating system (OS/9 Level II) wants 256 bytes per
sector. The OMTI 20C-1 controller can handle that but I'm not sure if
the ST-251 can.
Does anyone know if the ST-251 can support 256 bytes per sector and/or
how to configure it for 256 bytes per sector?
I have (well had) a ST-251-1 (so basically the same drive) that had 2
tracks formatted with 256 byte sectors, 2 tracks with 128 byte sectors and
the rest 512 byte sectors. The first 4 tracks were for some funky
'partitioning' software that either the controller or the disk driver for
the OS needed. It was some weird Epsom system, I think. It's been a while
and I traded it away years ago.
Warner