erik@mpx1.UUCP (Erik Murrey) (10/09/88)
SCO tells my that their ESDI version of Xenix
needs an OMTI ESDI card that differs from the WD-1007ESDI cards.
It allows the system to work with a 1:1 interleave, rather than
a 1:3, which would be the case using an St-506 looking ESDI card.
I want to use the 1:1 ESDI system, but I can't find a source for
the OMTI card ANYWHERE!
The system will be an AST 386 w/ a 150MB micropolis ESDI drive.
SCO says that it needs the OMTI 8620 or 8627 (what's the difference?)
If I use this card, how does the system boot if it doesn't look like
an ST-506 card? How does dos run? I would *hae* to think about
booting SCO from floppy every time I re-boot!
Thanks! Please e-mail responses!
--
Erik Murrey /| // /~~~~/ | /
MPX Data Systems, Inc. / | / / /____/ |/
erik@mpx1.UUCP / / / / /| Data Systems, Inc.
{spl1,vu-vlsi,bpa}!mpx1!erik / / / / |====================ipc@drexel.UUCP (Image Processing Center) (10/16/88)
In article <549@mpx1.UUCP>, erik@mpx1.UUCP (Erik Murrey) writes: > SCO tells my that their ESDI version of Xenix > needs an OMTI ESDI card that differs from the WD-1007ESDI cards. > It allows the system to work with a 1:1 interleave, rather than > a 1:3, which would be the case using an St-506 looking ESDI card. > > I want to use the 1:1 ESDI system, but I can't find a source for > the OMTI card ANYWHERE! > OMTI has discontinued the card due to lack of demand. But it seems to me that there is a misunderstanding about this 1:1 interleave business. SCO, like any other OS, doesn't know about the interleave factor of a track buffering controller. Track buffering controllers exist with the standard AT compatible interface. Therefore, you don't have a problem unless the WD1007 doesn't have a track buffer. Since much less expensive controllers, such as the WD1006 and Adaptec controllers have track buffers, I would expect that the WD1007 does also. The "ST506" paramter you mention has absolutely nothing do do with the controller to bus interface, or the interleave factor.
james@bigtex.cactus.org (James Van Artsdalen) (10/17/88)
In <775@drexel.UUCP>, ipc@drexel.UUCP (Image Processing Center) wrote: > OMTI has discontinued the card due to lack of demand. It also wasn't a very good design. Couldn't work under anything but DOS without a special driver. Didn't have a full-track buffer (it had about half a track of buffer - presumably that was enough to prevent overflow). Took up 1K of the lower 640K memory. I have one for sale real cheap. > SCO, like any other OS, doesn't know about the interleave factor > of a track buffering controller. Track buffering controllers exist > with the standard AT compatible interface. Yes, but keep in mind that there was a bug in the SCO driver at one point (may even be there now for all I know) that kept it from really working right with the WD1007. The symptom was abysmally low throughput, and the cause was the SCO driver sending "set drive parameter" commands to the controller every sector - dumping the buffer and causing the track to be re-read for each sector. > Therefore, you > don't have a problem unless the WD1007 doesn't have a track buffer. For the record, it definitely does. Its best feature is the drive remapping: it can make a 17 sec/trk drive with more than 1024 tracks appear to be a 34 sec/trk drive with half as many tracks, and the software (DOS, unix, OS/2) can't tell the difference. The only real problems are a truly terrible formatter and the fact that it can't handle the 15Mbit/sec drives yet (the 600meg Maxtor comes to mind). -- James R. Van Artsdalen james@bigtex.cactus.org "Live Free or Die" Home: 512-346-2444 Work: 338-8789 9505 Arboretum Blvd Austin TX 78759