james@bigtex.uu.net (James Van Artsdalen) (02/25/88)
I recently purchased a CDC Wren III-183 hard disk from a Compaq owner. I intend to use it in my PC's Ltd. 386/16. After a great deal of trouble, I noticed that my OMTI-8620 hard disk controller thought that this drive, which has 969 cylinders and 9 heads, only has 967 cylinders and 8 heads. Further investigation shows that indeed, the nineth head does not respond. I checked the CDC documentation, and the drive does have a nineth head. A friend at PC's Ltd said he had heard that Compaq "brain damaged" the drive for some unknown reason: he thought it might have something to do with Novell. I don't want Novell: I do want the missing 16meg of disk space. Compounding the problem is that fact that the PC's Ltd has a drive type entry for a normal Wren III-182, but not the Compaq damaged model. Does anybody know how to repair the Wren III-182? CDC would not talk to me when I called for anyone technical, and I don't want to send it to them for servicing (they might refuse to fix it, and might refuse to admit it's broken if Compaq wants to keep things hush-hush). -- James R. Van Artsdalen ...!uunet!utastro!bigtex!james "Live Free or Die" Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746
grr@cbmvax.UUCP (George Robbins) (02/26/88)
In article <856@bigtex.uu.net> james@bigtex.uu.net (James Van Artsdalen) writes: > I recently purchased a CDC Wren III-183 hard disk from a Compaq owner. I > intend to use it in my PC's Ltd. 386/16. After a great deal of trouble, I > noticed that my OMTI-8620 hard disk controller thought that this drive, which > has 969 cylinders and 9 heads, only has 967 cylinders and 8 heads. Further > investigation shows that indeed, the nineth head does not respond. I checked > the CDC documentation, and the drive does have a nineth head. You might check the OMTI documentation to make sure that the controller supports more than 8 heads, or whether any jumper arrangement is needed to make the controller notion of the 4'th head select line agree with the drive's. -- 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)
james@bigtex.UUCP (James Van Artsdalen) (02/28/88)
In article <3371@cbmvax.UUCP>, grr@cbmvax.UUCP (George Robbins) writes: > You might check the OMTI documentation to make sure that the controller > supports more than 8 heads, or whether any jumper arrangement is needed > to make the controller notion of the 4'th head select line agree with > the drive's. I forgot to mention it in my original article, but the Wren III-182 I have is an ESDI drive, and therefore knows how many heads/cylinders/sectors-per-track it supports. The OMTI makes use of this to set up the drive tables: one sets the drive type to zero (no drive), and during BIOS peripheral initialization, the OMTI builds the BIOS drive parameter table from the numbers the drive returns. Neatly avoids the BIOS drive type problem altogether. So I know that in fact the *drive* thinks it only has eight heads. In addition, I have spoken with someone who has used the OMTI with a normal CDC Wren III-182 without trouble (in DOS). -- James R. Van Artsdalen ...!uunet!utastro!bigtex!james "Live Free or Die" Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746
paul@vixie.UUCP (Paul Vixie Esq) (02/28/88)
In article <856@bigtex.uu.net> james@bigtex.uu.net (James Van Artsdalen)...
#noticed that my OMTI-8620 hard disk controller thought that this drive, which
#has 969 cylinders and 9 heads, only has 967 cylinders and 8 heads. Further
#investigation shows that indeed, the nineth head does not respond. I checked
#the CDC documentation, and the drive does have a nineth head.
The drive does have a ninth head, and the OMTI ought to be able to see it. If
it can't, something is bungled in the configuration -- ESDI drives report their
geometry to the controller, and if the drive were reporting nine heads, the
controller would see errors on the ninth one if it "weren't there".
Note that the drive does indeed only have 967 "user accessable" cylinders.
The last two (of 969 total) are used for bad sector remapping.
#A friend at PC's Ltd said he had heard that Compaq "brain damaged" the drive
#for some unknown reason: he thought it might have something to do with Novell.
Compaq has been known to do stuff like this.
#Does anybody know how to repair the Wren III-182? CDC would not talk to me
#when I called for anyone technical, and I don't want to send it to them for
#servicing (they might refuse to fix it, and might refuse to admit it's broken
#if Compaq wants to keep things hush-hush).
CDC doesn't care about Compaq's desire for hush-hush (if any). Send the
drive to CDC for repair or replacement, they do a good job.
--
Paul A Vixie Esq
paul%vixie@uunet.uu.net
{uunet,ptsfa,hoptoad}!vixie!paul
San Francisco, (415) 647-7023grr@cbmvax.UUCP (George Robbins) (03/01/88)
In article <870@bigtex.UUCP> james@bigtex.UUCP (James Van Artsdalen) writes: > In article <3371@cbmvax.UUCP>, grr@cbmvax.UUCP (George Robbins) writes: > > I forgot to mention it in my original article, but the Wren III-182 I have is > an ESDI drive, and therefore knows how many heads/cylinders/sectors-per-track > it supports. In this case it seems likely that it is a special order "OEM" version. There is probably a control microprocessor that is programmed slightly differntly so that it returns the "fradulent" geometry information. You might try to compare the drive to a "normal" unit and see if there is a micro-processor or ROM that has different part number/version identification on it. It may not be that easy to get CDC to "fix" the unit. In this case, you might try patching the driver or playing games to force it to use the "native" geometry... -- 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)
clewis@spectrix.UUCP (Chris R. Lewis) (03/02/88)
In article <3391@cbmvax.UUCP> grr@cbmvax.UUCP (George Robbins) writes: |In article <870@bigtex.UUCP> james@bigtex.UUCP (James Van Artsdalen) writes: |> In article <3371@cbmvax.UUCP>, grr@cbmvax.UUCP (George Robbins) writes: |> |> [ ESDI drives know their own geometry ] | |In this case it seems likely that it is a special order "OEM" version. There |is probably a control microprocessor that is programmed slightly differntly |so that it returns the "fradulent" geometry information. You might try to |compare the drive to a "normal" unit and see if there is a micro-processor |or ROM that has different part number/version identification on it. | |It may not be that easy to get CDC to "fix" the unit. In this case, you |might try patching the driver or playing games to force it to use the |"native" geometry... I'm pretty sure these things have EPROMs on them which contain the geometry along with the bad zone list. You might be able to simply order a new EPROM from CDC - though if the bad zone list is there you may have to figger out the bad spots yourself. -- Chris Lewis, Spectrix Microsystems Inc, UUCP: {uunet!mnetor, utcsri!utzoo, lsuc, yunexus}!spectrix!clewis Phone: (416)-474-1955
romwa@gpu.utcs.toronto.edu (Mark Dornfeld) (03/04/88)
The question here was the OMTI 8620 Controller recognizing the ninth surface on a CDC Wren III -183 ESDI disk. Consensys corporation in Toronto uses that combination and I believe they just start out with a low level DOS format and tell the controller that there are 9 heads. We have one system which they configured and it has 150 Mb of disk instead of the 130 which Compaq ships.
james@bigtex.UUCP (James Van Artsdalen) (03/05/88)
In article <1988Mar3.231020.428@gpu.utcs.toronto.edu>, romwa@gpu.utcs.toronto.edu (Mark Dornfeld) writes: > The question here was the OMTI 8620 Controller recognizing the > ninth surface on a CDC Wren III -183 ESDI disk. No, the question now is how to get the OMTI-8620 to recognize the ninth surface on a Compaq-modified Wren III-182. Turns out the drive probably has to be repaired: Compaq did something to both the drive electronics and the WD1007 controller they use with it, because the Compaq CPU sees the drive as having 16 heads and 17 sectors/track, neither of which is close. -- James R. Van Artsdalen ...!uunet!utastro!bigtex!james "Live Free or Die" Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746
cwwj@ur-tut.UUCP (Clarence Wilkerson) (03/05/88)
The declaration of 16 heads and 17 sectors.track was probably just to work around the 1024 cylinder limit, and the 17 sectors/track to be at the standard number. These probably do not influence the actual physical format of the disk.