30 Jun
2005
30 Jun
'05
3:04 p.m.
On Thu, 2005-06-30 at 16:30 -0400, Mike Loewen wrote:
On Thu, 30 Jun 2005, Ethan Dicks wrote:
At least in the Acorn world, lack of drives that'll support 256 bytes /
sector seems to be the main problem, as Acorn's SCSI controllers expect
to be talking to a bridge board which is only using 256 bytes / sector.
I have a hazy memory that it's possible with SCSI to do a read/write
operation and *not* use the full disk block size though - on a read you
just say "give me 256 bytes of block n" and on a write you supply only
256 bytes (and presumably the target pads out with zeros or something).
In other words it *might* be possible to use a device formatted with 512
byte blocks and just waste the upper half of every block (no big deal
given the choice of drives available now).
Still might need code changes though, and of course formatting /
filesystem generation tools might still have problems (and may need to
be done on a more modern machine even)
cheers
Jules
On 6/30/05, Mike Loewen <mloewen at
cpumagic.scol.pa.us> wrote:
Good question: I don't have the Sider drive itself, just the
controller. Back in the 8-bit days I couldn't afford a hard drive, so I
never had the chance to play with one on an 8-bit machine. I have a SASI controller for an Apple II
Sider hard drive, and have
found clues on the web that say older SCSI drives like the Seagate ST-225N
should work with it. Does that sound reasonable? What other make/model
SCSI drives would be likely to work?
Hmm... interesting... an ST225N might be something to try with the
D90x0, but one important question... does your Sider use 512-byte
blocks or 256-byte blocks? I've reformatted odd-sized blocks (528?)
to 512, but never to 256 bytes... was there a way of doing that back
in the old days? (I was playing with DEC hardware and kinda missed out
on hanging early hard drives on 8-bit micros)