dillon@CORY.BERKELEY.EDU (Matt Dillon) (09/10/88)
Oh, by the way, when you say the A2090 can handle ST506, you *DO* mean it can handle ST506 and ST412, don't you? -Matt
jesup@cbmvax.UUCP (Randell Jesup) (09/12/88)
In article <8809092138.AA05543@cory.Berkeley.EDU> dillon@CORY.BERKELEY.EDU (Matt Dillon) writes: > > Oh, by the way, when you say the A2090 can handle ST506, you *DO* >mean it can handle ST506 and ST412, don't you? Fairly certain (I can't remember the difference at the moment, but I think it's trivial). The 2090 does not support more than 8 heads at this time for ST506 drives (doesn't matter for SCSI). -- Randell Jesup, Commodore Engineering {uunet|rutgers|allegra}!cbmvax!jesup
ericb@athertn.Atherton.COM (Eric Black) (09/12/88)
In article <4702@cbmvax.UUCP> jesup@cbmvax.UUCP (Randell Jesup) writes: >In article <8809092138.AA05543@cory.Berkeley.EDU> dillon@CORY.BERKELEY.EDU (Matt Dillon) writes: >> >> Oh, by the way, when you say the A2090 can handle ST506, you *DO* >>mean it can handle ST506 and ST412, don't you? > > Fairly certain (I can't remember the difference at the moment, but >I think it's trivial). The 2090 does not support more than 8 heads at this >time for ST506 drives (doesn't matter for SCSI). > >-- >Randell Jesup, Commodore Engineering {uunet|rutgers|allegra}!cbmvax!jesup I'm certain. I'm running an ST-251 40MB disk, which has the ST412 interface, on my A2090, and it runs just fine. -- Eric Black "Garbage in, Gospel out" Atherton Technology, 1333 Bordeaux Dr., Sunnyvale, CA, 94089 UUCP: {sun,decwrl,hpda,pyramid}!athertn!ericb Domainist: ericb@Atherton.COM
thad@cup.portal.com (09/14/88)
Sorry, the A2090 is *NOT* ST-412 compatible. The major difference between ST-506 and ST-412 is that ST-506 supports only 8 heads (such as the older WD1010 controllers) and that ST-412 supports 16 heads. The A2090 supports only 8 heads, thus is ST-506 compatible. The Seagate ST-251 drive has 6 heads and will function with either an ST-506 or ST-412 compatible controller. Thad Floryan [thad@cup.portal.com (OR) ...!sun!portal!cup.portal.com!thad]
grr@cbmvax.UUCP (George Robbins) (09/17/88)
In article <9071@cup.portal.com> thad@cup.portal.com writes: > Sorry, the A2090 is *NOT* ST-412 compatible. > > The major difference between ST-506 and ST-412 is that ST-506 supports only > 8 heads (such as the older WD1010 controllers) and that ST-412 supports 16 > heads. Sorry, wrong. The main difference between the ST506 and ST412 is that the ST412 supports buffered seeking, that is you can twiddle the step line real fast and then wait of the drive to say it is ready instead of having the count the milliseconds between step pulses. The A2090 and almost any other controller you want to name do support buffered seeks and are therefore ST412 compatible, so in a pracitical sense, the difference between ST506 and ST412 is a historical irrelevancy. > The A2090 supports only 8 heads, thus is ST-506 compatible. > > The Seagate ST-251 drive has 6 heads and will function with either an ST-506 > or ST-412 compatible controller. That's more reasonable. The 8+ head drives reassign one of the control signals for the 3'rd head select line. Traditionally, this has only occurred on the high-capacity/high-doller drives by Maxtor and others, but these drives are now showing up on the surplus market for ~$1K... -- George Robbins - now working for, uucp: {uunet|ihnp4|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@uunet.uu.net Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
thad@cup.portal.com (09/19/88)
Hi George (grr@cbmvax), Thanks for posting the additional info re: ST506 and ST412 differences. I didn't; I kept my original answer within the context of the original question (number of heads). I didn't see need to enter several pages of specs! :-) Re: large drives: yes, they're really dropping in price on the surplus market (re: NEW drives). 380MB Maxtors can be purchased for under $2,000 each; Dale Luck just purchased 3 and I purchased 2; mine work fine with the Supra 4x4 (on A1000) but Dale was unable (as of last week) to get his to function with the A2090A (the XT-3380 are embedded SCSI drives; you may wish to check with Dale and/or Kodiak re: their analysis of the problem(s)). Thad Floryan [thad@cup.portal.com (OR) ...!sun!portal!cup.portal.com!thad]
bosch@dg.dg.com (Derek Bosch) (06/14/90)
I purchases a used A2090 controller when I upgraded to an A2000, and unfortunately, it did not come with any documentation. I have successfully managed to get an ST506 drive working, but would like some information on actually reading/writing SCSI commands from/to it. If anyone has any relevant information about writing software for this controller, or can point me to a good source, I would be extremely grateful. Derek Bosch -- "There's a fine line between stupid and being clever" -- Spinal Tap