kwgst@unix.cis.pitt.edu (Karol W Gieszczykiewicz) (02/02/91)
Greetings. I already know what a ST-406 is (6MB 99ms) Now, someone told me that the SASI interface is a relative of SCSI. Does anyone know if I can hook up a hard drive to the ST506 side and the SASI side to a Macintosh and expect this to work? The controller is a Xebec 10426 (or 104527). It's just a PC board that has a 50-pin SASI input and outputs for 2 ST-506 drives. Can I expect this to work a _little_ with a Mac or will I most likely see smoke? (By the way, anyone want the St406? I want the stepper out of it (~$15.00 in surplus stores) but if someone pays me more than that, it's yours :-) Plus shipping. No, you can't use it with an AT...) Take care. P.S. Also looking for a cheap S100 card cage. Preferably 12 or more slots. Power supply not needed (you can keep it :-) I plan to use a switcher (1200Watt :-) Must be cheap but in good shape. E-mail with quote on shipping if interested in selling. -- ------------------------------------------------------------------------------ If reply bounces, try "kwgst@pittvms"... no? try "fmgst@unix.cis.pitt.edu" Did you hear? Some Poles burned the Russian flag near the Soviet embassy, in Poland. :-) :-) "Nothing is impossible if you don't have to do it yourself."
henry@zoo.toronto.edu (Henry Spencer) (02/03/91)
In article <86715@unix.cis.pitt.edu> kwgst@unix.cis.pitt.edu (Filip Gieszczykiewicz) writes: > Now, someone told me that the SASI interface is a relative > of SCSI. SASI is SCSI's grizzled old ancestor. They are nominally still interoperable, last I heard. > Does anyone know if I can hook up a hard drive > to the ST506 side and the SASI side to a Macintosh and > expect this to work? Maybe. There is no *fundamental* reason for this to be unworkable, but much depends on details. (E.g., is the Mac expecting a more modern controller and trying to exploit post-SASI features?) -- "Maybe we should tell the truth?" | Henry Spencer at U of Toronto Zoology "Surely we aren't that desperate yet." | henry@zoo.toronto.edu utzoo!henry
abeals@autodesk.com (Segments Are For Worms) (02/05/91)
henry@zoo.toronto.edu (Henry Spencer) writes: >In article <86715@unix.cis.pitt.edu> kwgst@unix.cis.pitt.edu (Filip Gieszczykiewicz) writes: >> Now, someone told me that the SASI interface is a relative >> of SCSI. >SASI is SCSI's grizzled old ancestor. They are nominally still interoperable, >last I heard. Uh, not really. In SASI-land, all you had to do in order to access the remote device was to assert its SASI ID during the selection phase. In SCSI-land, you need to assert both the controller's SCSI ID and the remote device's SCSI ID on the bus during the selection phase. >> Does anyone know if I can hook up a hard drive >> to the ST506 side and the SASI side to a Macintosh and >> expect this to work? >Maybe. There is no *fundamental* reason for this to be unworkable, but much >depends on details. (E.g., is the Mac expecting a more modern controller >and trying to exploit post-SASI features?) More to the point: the mac is expecting a few basic commands to be available so it can download a proper driver from the first N blocks of the hard drive. Where are you going to get a controller for it, even if the mac can operate the SASI device? Unless you're really shy of dollars, I'd just go for a 20meg hard drive and build one of the many "cheep scsi drives" projects that appear in the magazines from time to time. -- Andrew Scott Beals abeals@autodesk.com
bender@oobleck.Eng.Sun.COM (Michael Bender) (02/05/91)
(about the MAC<->SASI connection question): I don't know about the Mac's SCSI interface or s/w, but I suppose that you could buy one of those Adaptec or Emeulex ST-506<->SCSI host adapters at a surplus place and try that out. In this are at least there are several surplus shops that sell these adapters, although never having needed the ST-506<->SCSI connection, I can't tell you how well they work or what they cost. You might try giving the following place a call: Wierd Stuff Wearhouse aka Surplus Solutions Milpitas, CA it's in the 408 area code, I don't have the number handy, but there's always 408-555-1212 :-> good luck! mike -- Won't look like rain, Won't look like snow, | DOD #000007 Won't look like fog, That's all we know! | AMA #511250 We just can't tell you anymore, We've never made oobleck before! | MSC #298726
vail@tegra.COM (Johnathan Vail) (02/07/91)
In article <abeals.665691230@melange> abeals@autodesk.com (Segments Are For Worms) writes: henry@zoo.toronto.edu (Henry Spencer) writes: >In article <86715@unix.cis.pitt.edu> kwgst@unix.cis.pitt.edu (Filip Gieszczykiewicz) writes: >> Now, someone told me that the SASI interface is a relative >> of SCSI. >SASI is SCSI's grizzled old ancestor. They are nominally still interoperable, >last I heard. Uh, not really. In SASI-land, all you had to do in order to access the remote device was to assert its SASI ID during the selection phase. In SCSI-land, you need to assert both the controller's SCSI ID and the remote device's SCSI ID on the bus during the selection phase. There are lots of reasons why SCSI!=SASI and although what you say is true it may not hinder interoperation. An example of this is the OMTI SCSI controller which will work fine without the initiator's ID line asserted during selection phase. This is a case of a SASI interface working with a SCSI device. As long as you stick with a small subset of SCSI commands and don't do anything fancy with arbritration or disconnect/reselect this has a good chance of working. I would think that it would be much less likely that the opposite, as descibed in the original posting, would stand a chance of working. jv "theobromine: a compound which, contrary to it's name, contains neither bromine nor God" -- David Throop _____ | | Johnathan Vail | n1dxg@tegra.com |Tegra| (508) 663-7435 | N1DXG@448.625-(WorldNet) ----- jv@n1dxg.ampr.org {...sun!sunne ..uunet}!tegra!vail
ts@cup.portal.com (Tim W Smith) (02/07/91)
>>SASI is SCSI's grizzled old ancestor. They are nominally still interoperable, >>last I heard. > >Uh, not really. In SASI-land, all you had to do in order to access >the remote device was to assert its SASI ID during the selection phase. >In SCSI-land, you need to assert both the controller's SCSI ID and the >remote device's SCSI ID on the bus during the selection phase. You have fallen for one of the classic blunders. The most famous, of course, is never to get involved in a land war in Asia, but almost as famous is this: never disagree with Henry Spencer on Usenet on factual matters where computers are involved. See section 5.1.3.4 of Revision 17B of the SCSI specification. In single initiator systems where the initiator does not allow the RESELECTION phase, the inititator only needs to assert the target devices's ID bit on the bus during selection. Don't feel bad, though. There are in fact some SCSI chips that will not allow themselves to be selected unless two bits are asserted, so one would have to be rather unconcerned about interoperability to actually take advantage of this. Tim Smith ps: don't ask which chips I am talking about, because I don't remember. I remember that some peripheral firmware I wrote did not seem to respond to selection, and I tracked the problem down to an initiator that was only asserting one bit (due to a broken wire in the #@$%^& cable), and so the selection was being ignored by the SCSI chip in the target. Thus, I remember that there is at least one chip out there that will not recognize such a selection, but I don't remember which one it is.
henry@zoo.toronto.edu (Henry Spencer) (02/08/91)
In article <39010@cup.portal.com> ts@cup.portal.com (Tim W Smith) writes: >You have fallen for one of the classic blunders. The most famous, of >course, is never to get involved in a land war in Asia, but almost >as famous is this: never disagree with Henry Spencer on Usenet on >factual matters where computers are involved. Well, hardly ever. :-) I actually have been known to be wrong about such things on occasion. Not too often, thank heavens. -- "Maybe we should tell the truth?" | Henry Spencer at U of Toronto Zoology "Surely we aren't that desperate yet." | henry@zoo.toronto.edu utzoo!henry
cah@gripl.UUCP (Chris Heitmann) (02/19/91)
SASI stands for Shugart Associates System Interface and came into being in
the late 1970's.
Chris Heitmann
cah@gripl.uucpwhit@milton.u.washington.edu (John Whitmore) (02/28/91)
In article <86715@unix.cis.pitt.edu> kwgst@unix.cis.pitt.edu (Filip Gieszczykiewicz) writes: > > Now, someone told me that the SASI interface is a relative > of SCSI. Does anyone know if I can hook up a hard drive > to the ST506 side and the SASI side to a Macintosh and > expect this to work? SASI uses one less wire than SCSI; if you make sure that this wire (/ATN, pin 17 on the Macintosh DB-25) is not kept grounded by your SASI box, then it should be possible to use nonstandard SCSI drivers (of which several are floating around) to read/write to your SASI controller. The command set, however, of SCSI is well established; SASI is likely to be missing some part of the 'common command set', and you will need to know how to write a driver that works around this problem. I don't know of anyone who's actually done this, but the subject does come up from time to time. John Whitmore