tim@maths.tcd.ie (Timothy Murphy) (09/21/90)
What board would you advise for using a SCSI drive (a) on a PC/XT, (b) on an AT? I see some really cheap ($30-40) boards advertised, while others are much more expensive. What is the difference? Any info on actual boards, and experience using them, gratefully received. -- Timothy Murphy e-mail: tim@maths.tcd.ie
iverson@xstor.UUCP (Tim Iverson) (09/26/90)
In article <1990Sep20.175400.18626@maths.tcd.ie> tim@maths.tcd.ie (Timothy Murphy) writes: > What board would you advise for using a SCSI drive (a) on a PC/XT, (b) on > an AT? I see some really cheap ($30-40) boards advertised, while others > are much more expensive. What is the difference? Any info on actual > boards, and experience using them, gratefully received. > >Timothy Murphy >e-mail: tim@maths.tcd.ie It really depends more on what OS you're going to be running, not on the machine. If you're going to run UNIX or some other multiprocessing OS, then the more expensive boards (e.g. the Apaptec 154x series) are nicer to have. This kind of board does 1st party DMA - moves bytes from disk to memory all by itself - which frees up the CPU for other tasks. Unfortunately, this type of offloading has a rather high overhead on each command. The cheap boards require the CPU to move the bytes around, but generally have much lower overhead. So, if you use DOS, the expensive bus-mastering boards are actually slower than their cheap counterparts. Of course, when buying a cheap board it's often hard to know which firm is reputable: we had one manufacturer that claimed a 10x jump in transfer rate for any drive. Well, we tested it and sure enough, the benchmark showed that this little poky 200k/s seagate was doing 2M/s. Since this was physically impossible, we investigated and found that interrupts were deliberately being disabled in the BIOS, presumably to prevent the timer from ticking, thus giving a skewed reading on the benchmark. I realize that you would like names rather than general advice, but other than the Adaptec 154x (good for UNIX), there are no other boards that I can give a positive recomendation for. Hope this helps. - Tim Iverson uunet!xstor!iverson
rkumar@rnd.GBA.NYU.EDU (Rachna Kumar) (09/26/90)
I am looking for a software which will allow me at read/write to a video buffer through its SCSI interface. I can use the SCSI port from MAC or PC for this purpose. This way I will be able to save the video image from the buffer to the removal hard disk for later viewing. Are there any softwares availble which will allow me to do this? Do I have to write my own SCSI driver for this purpose? How much work will this be? Are there any good books available on this topic? I need all the help I can get. I am new to this so any help you can provide will be much appreciated. Thank you.
strike@clmqt.marquette.Mi.US (Tim Bowser) (09/27/90)
tim@maths.tcd.ie (Timothy Murphy) writes: >What board would you advise for using a SCSI drive >(a) on a PC/XT, (b) on an AT? a: Seagate ST-01 or -02, depending on where the floppy controller is. b: DPT's SCSI Host adaptor or Adaptec's 154xB SCSI Host Adaptor. Be forewarned that the Adaptec did not work in my clone machine with an early model AST XFormer 286 motherboard. DMA Arbitration conflicts. It is running magnificently in my 386SX machine under SCO Xenix 2.3.2GT. -- Tim Bowser ("Strikemaster") | Standard | mailrus!sharkey!clmqt!strike Enterprise Information System | Disclaimer | strike@clmqt.marquette.Mi.US Marquette, Mi. USA | Here | Voice:(906)-346-6735 => UNIX: The Adventure Begins... To vi, or not to vi, that is the question. <=
blair@pyro.ei.dupont.com (Grant Bair) (09/27/90)
>tim@maths.tcd.ie (Timothy Murphy) writes: > >>What board would you advise for using a SCSI drive >>(a) on a PC/XT, (b) on an AT? > I can't comment upon (a), but as regards (b) we use the Western Digital WD7000 boards for all SCSI I/O. This is not only to regular SCSI hard drives, but also to Crosfield Studio systems, optical disks and SCSI printers. We've had no problems in general. The only exceptions we've noted are: 1) If you have a NEC 386/25MHz it's a no-go (this NEC is not considered a true AT-clone) 2) If you want to use VM/386 or a similar product in conjunction with more than one (virtual or physical) drive. Grant. -- +-----------------------------------------------------------------------------+ |Grant C Blair, DuPont Imaging Systems, Newark, DE 19702, USA | |blair@pyro.ei.dupont.com (192.58.195.64) (302)-733-9533 | +-----------------------------------------------------------------------------+
scjones@thor.UUCP (Larry Jones) (09/29/90)
> >What board would you advise for using a SCSI drive > >(a) on a PC/XT, (b) on an AT? > > a: Seagate ST-01 or -02, depending on where the floppy controller is. You should either buy a Yugo... > b: DPT's SCSI Host adaptor or Adaptec's 154xB SCSI Host Adaptor. or else buy a Cadillac or a Lincoln. Why oh why aren't there any "midsize" SCSI host adapters? ---- Larry Jones UUCP: uunet!sdrc!thor!scjones SDRC scjones@thor.UUCP 2000 Eastman Dr. BIX: ltl Milford, OH 45150-2789 AT&T: (513) 576-2070 I wonder if you can refuse to inherit the world. -- Calvin
tim@ziggurat.gg.caltech.edu (09/30/90)
In <190@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes: >> >What board would you advise for using a SCSI drive >> >(a) on a PC/XT, (b) on an AT? >> >> a: Seagate ST-01 or -02, depending on where the floppy controller is. >You should either buy a Yugo... >> b: DPT's SCSI Host adaptor or Adaptec's 154xB SCSI Host Adaptor. >or else buy a Cadillac or a Lincoln. >Why oh why aren't there any "midsize" SCSI host adapters? What about Future Domain? Tim
larry@nstar.uucp (Larry Snyder) (10/01/90)
tim@ziggurat.gg.caltech.edu writes: >What about Future Domain? Future Domain throughput is so very slow as compared against the Adaptec 1542 -- Larry Snyder, Northern Star Communications, Notre Dame, IN USA {larry@nstar, uunet!sco!romed!nstar!larry, nstar!larry@ndmath.math.nd.edu} backbone usenet newsfeeds available Public Access Unix Site (219) 289-0282 (5 high speed lines)
liggio@cunixf.cc.columbia.edu (Vincent J. Liggio) (10/01/90)
In article <190@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes: >> >What board would you advise for using a SCSI drive >> >(a) on a PC/XT, (b) on an AT? >> >> a: Seagate ST-01 or -02, depending on where the floppy controller is. > >You should either buy a Yugo... > >> b: DPT's SCSI Host adaptor or Adaptec's 154xB SCSI Host Adaptor. > >or else buy a Cadillac or a Lincoln. > >Why oh why aren't there any "midsize" SCSI host adapters? >---- >Larry Jones UUCP: uunet!sdrc!thor!scjones Oh, but there are. There is the Adaptec 1520, about $160. I'm personally looking for a SCSI interface for my Mylex 33mhz 386, and I was talking to a technician at Direct Drives (check Computer Shopper). I was looking for a SCSI-2 interface, and the 1520 is one, and it is designed as a mid-range controller. It supports SCSI-1 (a subset of 2), although it is not as fast as the SCSI-2 standard is supposed to be (up to 5 meg/sec), it is comparable, if not a bit faster than the SCSI-1. It looks good to me, because I want a SCSI-2 drive (I'm open for suggestions, if anyone has any), and the only ones I found were Quantum drives, and they only go upt to 170 mb (the 210's are out of stock until December). I don't want a SCSI-1 drive because I'd like to stay with the new stuff instead of the outgoing SCSI-1. Vince Stallion Tigger +----------------------------------------------------------------------------+ | Rolm : (212) 853-6043 | | USnail : 533 John Jay Hall, Columbia University, NY, NY 10027 | | INTERNET : liggio@cunixf.cc.columbia.edu | | BITNET : liggio@cunixf.bitnet | | UUCP : {rutgers,topaz}!columbia!cunixf!liggio | +----------------------------------------------------------------------------+