29 Nov
2011
29 Nov
'11
2:02 p.m.
As a follow up to Richard's question, does anyone have any experience
archiving an Xebec S1410 / S1410A SASI controlled drive from a
relatively modern system? If the SASI controller doesn't support the
standard SCSI Inquiry and Read Capacity commands I wouldn't expect
that you could simply connect it to a SCSI host controller on a Linux
box and "dd" the drive contents to a disk image file.
-Glen
30 Nov
30 Nov
4:58 a.m.
On Tue, 29 Nov 2011, Glen Slick wrote:
As a follow up to Richard's question, does anyone
have any experience
archiving an Xebec S1410 / S1410A SASI controlled drive from a
relatively modern system? If the SASI controller doesn't support the
standard SCSI Inquiry and Read Capacity commands I wouldn't expect
that you could simply connect it to a SCSI host controller on a Linux
box and "dd" the drive contents to a disk image file.
I have sources for a Linux ACB-40xx device driver that might be a basis
for getting the Xebec working. However:
- It's for Linux kernel version 1.2.9 circa-1994
- The Adaptec ACB-40xx boards read their geometry information from a
reserved area on the drive, while the Xebec required this either
hard-coded in EPROM or set by the host at power up.
If you are interested in hacking this into shape, drop me e-mail privately
and I'll send you a tarball.
Steve
--
5 p.m.
Glen Slick wrote:
As a follow up to Richard's question, does anyone
have any experience
archiving an Xebec S1410 / S1410A SASI controlled drive from a
relatively modern system? If the SASI controller doesn't support the
standard SCSI Inquiry and Read Capacity commands I wouldn't expect
that you could simply connect it to a SCSI host controller on a Linux
box and "dd" the drive contents to a disk image file.
I think for starters you'll have problems connecting a SASI device to a
SCSI HBA - I've not touched this for a few years, but isn't there an extra
phase in the SCSI protocol (not to mention a couple of signals) that just
isn't there for SASI? (because SASI was more of a single-device protocol,
whereas SCSI supported multiple devices on the bus)
When I looked into this it was mainly with one of the Adaptec bridges
(which are "SCSI", but lack Inquiry support), but I had a few systems which
used the Xebec and OMTI boards, too - my conclusion was that it was easier
to build myself a completely-dumb controller and talk to the boards that
way, crafting SCSI/SASI commands in software, than it was to try and
somehow integrate[1] the boards into a Linux environment at a low level. I
got as far as rustling up some hardware, but then moved overseas - so
everything's been in storage since then; I'll get back to it one day.
[1] one issue was that the Linux kernel - at least then - "offlined"
anything that didn't respond to Inquiry at boot, so it wasn't possible to
craft sg commands and throw them at the device once booted, even if the
device itself was sufficiently SCSI-like to play nicely on the bus. Maybe
that's changed these days.
Most - possibly all - of these bridge boards seemed to support some form of
vendor-unique command to define the device parameters (even if they also
did so via board firmware or 'hidden' sectors), so I don't think any lack
of a "read capacity" type command would be an issue; it'd be a case of
issuing the necessary setup command and then from there treating the device
like a linear sequence of blocks.
Oh, one other possible gotcha with the Xebec boards - ISTR they supported
the notion of running custom firmware according to a vendor's
specifications. What I don't know is if that only went as far as
initializing device parameters, or if there might be Xebec boards out there
with firmware so tweaked that it doesn't follow any of the standard
SCSI/SASI command definitions.
cheers
Jules
5:13 p.m.
On 30 Nov 2011 at 19:00, Jules Richardson wrote:
I think for starters you'll have problems
connecting a SASI device to
a SCSI HBA - I've not touched this for a few years, but isn't there an
extra phase in the SCSI protocol (not to mention a couple of signals)
that just isn't there for SASI? (because SASI was more of a
single-device protocol, whereas SCSI supported multiple devices on the
bus)
SASI is comparatively dumb compared to SCSI. You should be able to
rig up an interface with some random TTL if you have a system with a
simple bus (e.g. ISA), or at worst, a microcontroller such as the
Arduino.
My first hard disk on my 5150 was an SA1001 with a WD SASI-interfaced
controller. My PC interface card was less than a half-sized ISA
card.
I've got a full-length Ampex Megastore SASI interface card for the
ISA bus that equally sparse, but includes a 2732 EPROM BIOS
extension.
--Chuck
4540
days inactive
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3 comments
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participants (4)
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