barton@killer.DALLAS.TX.US (Barton Fisk) (09/02/88)
Forgive my ignorance, but I was just informed by NCR's PC support line that the controller board in my NCR pc8 would only support drives with a ST506 interface, and that ST412 would not work. My question is: What is the difference between ST412 and St506? Do these people know what they are talking about? Also, I would like to hear from any NCR PC users out there about problems you are having, or have had. In particular, I would be interested in finding others running some *nix on an NCR pc. I know there are some incompatibilities with their machines, and would be interested in any others findings. Barton A. Fisk uucp: killer!barton Barton A. Fisk & Co., Inc. P.O. Box 1781 Lake Charles, La. 70602 (318) 439-5984 -------------------------------------------------------- +++++++ Can anything good come out of Louisiana? ++++++ --------------------------------------------------------
plocher@uport.UUCP (John Plocher) (09/06/88)
In article <5389@killer.DALLAS.TX.US> Barton Fisk writes: >My question is: What is the difference between ST412 and St506? The 506 was a 6 mb unformatted drive (5 formatted), the 412 was 12 mb (10) >Do these people know what they are talking about? I'd guess not - the drives have the same interface, and besides, no one in their right mind uses a 5Mb hard drive any more :-) >Barton A. Fisk uucp: killer!barton -John Plocher
uhclem@trsvax.UUCP (09/06/88)
B>My question is: What is the difference between ST412 and St506? B>Do these people know what they are talking about? I recently came across an important difference between the ST506 and drives claiming to be ST412's. I got a ST4096, a ST412 drive and tried to use it with a ST506 controller for a non-clone system. Would work great until it reached cylinder 512, then it would fault. Problem was, in the ST506 drives pin 2 (believe that is right) was for Reduced Write Current (RWC). The ST412 drives are smart enough to either not need RWC at all or know internally when to do it themselves. (Usually the host simply asserted that signal at the halfway mark.) This freed up a line in the interface that is now used for Head Select 3 (zero based), allowing up to 16 heads. On my system, only 8 heads were allowed anyway and I was willing to toss the 9th head because I got a 1024x9 drive cheaper than a 1024x8 of similar performance. Anyway, what would happen is that the host controller would signal RWC at the halfway mark (cylinder 512) and the drive would take that to mean, Select upper 8 heads. Very quickly after that things went a bit crazy. Solution, bit of tape over pin two on the ST412 connector and things are are running fine. <My opinion, and not that of my employer, who stopped reading this note when the phrase "non-clone" appeared and started burning the phospher.> "Thank you, Uh Clem." Frank Durda IV @ <trsvax!uhclem> ...decvax!microsoft!trsvax!uhclem ...sys1!hal6000!trsvax!uhclem I've come to praise ihnp4, not to send mail through him.