Re: Help with SCSI-2

[lkhaider@concentric.net (Laer Haider)]

dempson@actrix.gen.nz (David Empson) wrote:
>Laer Haider <lkhaider@concentric.net> wrote:
>
>> I received a free Seagate ST-3610N 535MB SCSI-2 HDD (technical details
>> follow).  I was hoping to use it on my IIgs as a replacement HD
>> (faster and bigger), but ran into some trouble.
>
>[Details snipped]
>
>This drive certainly should work on the IIgs, with either a RamFast or
>Apple SCSI card.
>
>There are some newer drives (notably the Quantum Fireball) which do not
>work with a RamFast, because they require a specific SCSI feature which
>is not supported by the RamFast (but is supported by the Apple cards).
>
>I doubt this is the problem here, because these drives don't work at all
>if you try to use them with a RamFast.
>
>The most likely cause is improper SCSI termination.  There should be one
>terminator (either passive or active) at the end of the drive chain.

I've checked every possible combination of SCSI termination.  I have
an old-fashion SCSI termination block at the end of the SCSI chain and
I've also tried a pass-through terminator, and both together at
different points in the chain.

>There might also be some odd conflict with other devices on the bus.
>Some weird SCSI problems can be solved by rearranging the order of
>devices, removing other devices, or by over-terminating or
>under-terminating the bus.

I've reordered, removed, and juggled.  There are three devices on the
bus.  Same problem in every case.

>Do you know anyone who has an Apple SCSI card?  It would be interesting
>to try the drive on that, and see if it works, or at least to see if
>there are different symptoms.

I have an Apple HS-SCSI card that I tried.  The computer didn't even
recognize the device was there.

>> Am I missing something here?  Are SCSI-2 devices not compatible with
>> the RamFAST?  Not compatible with SCSI-1 devices?  The Apple IIgs?  Is
>> there some hardware hack I can do?  Some driver I can use?
>
>In general, SCSI-2 devices are compatible with SCSI-1 devices.  The main
>difference between SCSI-1 and SCSI-2 for hard drives is that SCSI-2
>drives implement a more standard command set, and that SCSI-2 supports
>"Fast SCSI" (an optional feature which is not supported on an Apple II
>anyway).

The drive is a "Fast SCSI" device, so do you think that's the hang up?

>SCSI-2 also standardised many other device types (e.g. CD-ROM drives).

That's why I've been so pleased with my Adaptec SCSI-2 interface on my
PC.  I only wish that SCSI on the RamFAST could be as easy as it has
been with the Adaptec.

Any other ideas?
--
Laer Haider     lkhaider@concentric.net