30 Jun
2005
30 Jun
'05
1:35 p.m.
On 6/30/05, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
I was under the impression that SASI was sufficiently
close to SCSI that
a SCSI interface could talk to a SASI device given the right software. It
would probably make things simpler if the SASI device and the controller
were the only things on the bus.
Your postings probably crossed in the aether, but I think that's what
Allison was saying - the interfaces are close, electrically (ISTR
parity was new with SCSI), but there can be some incompatibilies at
the command-set level. - i.e. - changing the firmware for the
controller (or host) can allow one to use the other type of device
from what was originally intended.
To tie this in to what I was saying earlier, I've wanted to recode the
firmware for the D90x0 drives for a number of years, but have never
torn it apart far enough to consider reconstructing it for SCSI, plus
there's the 512-byte/256-byte issue (the D90x0 instructs the SASI
bridge card to format the tracks as 32 256-byte sectors rather than
the more ordinary and more modern 17 512-byte sectors). That, to my
level of understanding about embedded SCSI drives, is a show-stopper.
-ethan