Re: Which present HD mechanisms are compatible with the

[nparker@cie-2.uoregon.edu (Neil Parker)]

In article <4pnc4h$i6b@borg.svpal.org> wily@svpal.svpal.org (Paul Creager)
writes:
>Kenneth C. Richardson (kcr103@psuvm.psu.edu) wrote:
>: I recently purchased a Fireball 540 mechanism and it does NOT work with
>: my
>: RamFast SCSI controller.  Before I go out and buy another mechanism,
>: what models will work with the RamFast?  Does a Trailblazer work? 
>
>What exactly do you mean it doesn't "work"?  Did the RF Utility recognize 
>the drive?  Did you make sure it had a unique SCSI ID?  More details, please.
>
>The RamFast should work with any SCSI-I/SCSI-II device.  SCSI-II is 
>supposed to be backward compliant.  I had no trouble with my Quantum 
>Lightning 365.

Apparently not all SCSI-2 drives work with the RamFast.

I don't actually own a RamFast, so I can't vouch for the absolute accuracy
of this, but from previous discussions about this very subject, it appears
that the RamFast uses the SCSI-1 "single initiator option" (which allows
the controller to skip the SCSI bus arbitration phase), and no-host-ID
option (which allows a controller to not have its own SCSI ID number).

The problem is that neither of these options are part of the SCSI-2
standard.  According to the final SCSI-2 draft proposal, a SCSI-2 device
may choose to implement those two options for compatibility reasons, but
need not do so.  Any device that doesn't support those options probably
won't work with the RamFast.

I have a vague recollection that the last time this topic came up, the
Quantum Fireball was mentioned as one of the drives that doesn't support
those options.

              - Neil Parker

P.S.  My guess is that the drive would work just fine if you plugged it
into an Apple SCSI card.  My Apple Rev C SCSI Card does SCSI bus
arbitration, and asserts its own host ID during the select phase.
-- 
Neil Parker, nparker@{cie-2,cie}.uoregon.edu, http://cie-2.uoregon.edu/~nparker

                     "Bad move, Neil!"  -- The Tick