Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cbmvax!thomas
From: thomas@cbmvax.UUCP (Dave Thomas QA)
Newsgroups: comp.sys.amiga
Subject: Re: 15 Head Hard drive and the A2090(a)
Message-ID: <6993@cbmvax.UUCP>
Date: 26 May 89 13:02:49 GMT
References: <8388.AA8388@heimat>
Reply-To: thomas@cbmvax.UUCP (Dave Thomas QA)
Organization: Commodore Technology, West Chester, PA
Lines: 37

In article <8388.AA8388@heimat> sneakers@heimat.UUCP (Dan "Sneakers" Schein) writes:
> In Message <17399@usc.edu>, papa@pollux.usc.edu (Marco Papa) writes:
> +--
> |In article <8356.AA8356@heimat> sneakers@heimat.UUCP (Dan "Sneakers" Schein) writes:
> |>  True, BUT not to be overlooked (ill mention it since no one else has so far)
> |>  is the fact that with an adapter (like the Adaptec 4000A or 4070) you can
> |>  run your ST-506 drive from the SCSI port. This is great for running drives
> |>  with > 8 heads -or- for running up to 4 ST-506 drives off one 2090 ;-)
> |								 ^^^^
> |
> |Except that none of the Adaptec adapters can be "prep"-ed with the 2090 or
> |2090A. Some claim that after prepping an Adaptec with "another" adapter,
> |the resuling disk will be recognized by the 2090x, but I have no direct
> |experience of this.
> +--
>   I have no hands on experience with this on an Amiga either, but I have made
>   it work on a MAC, and I have used a MAC (genuine Apple) SCSI drive on my
>   2090. Based on this I presumed (perhaps wrongly) that it would work. If
>   anyone has first hand info on if this works (or not) with the CBM 2090
>   boards, I welcome e-mail with the details. Since I had planned on using
>   this trick later this summer ;-).
> 
>   Sneakers
> 

It's true, Dan.  The 2090 prep software does not know how to handle an
Adaptec.  The Adaptec needs a "Mode Select" SCSI command before doing
a low level format.  This tells the adaptec the physical drive parameters.
Real SCSI drives don't need (or want) this since the drive already knows
about itself.  It *should* be possible to write a program which does the
mode select and low level format.  Once that is done (it is a one shot
thing), you could prep normally.

Dave
-- 
Dave Thomas, Commodore Amiga Test Engineering
UUCP  ...{allegra,rutgers}!cbmvax!thomas