clear@cavebbs.gen.nz (Charlie Lear) (12/10/90)
Sorry if this is part of a FAQ post, but here it is anyway! I have a 3B2/400 with twin CDC-Wren 72MB MFM disks. One of the drives is quite flakey and I've partitioned off about 15MB that contains a minefield of bad sectors. I have been very kindly offered a Seagate ST4096 to replace it. Obviously it has a larger capacity and different geometry from the CDC. Therefore it is not supported directly by the firmware. Running SysV 3.2 and using a current idtools disk, would I be able to format it to 80MB or would I have to de-rate it to 925 cyls and call it a CDC? Please post; I'm interested in any experiences people have had in putting non-ATT-listed disks in 3B2's. I saw a thread a month or so back about using a Maxtor XT1140 120MB disk, but didn't pay a lot of attention as the New Zealand list price for an 1140 is NZD$5546 (USD$3383). For those bucks I would rather write off the 3B2 and buy a 600MB disk and 16-port card for my 386... nahh, I couldn't write off the 3B2. I'd rather keep it going and reduce the 386/iX mob to inCoherent rage... 8-) -- -------------------------------------------------------------------------- Charlie "The Bear" Lear | clear@cavebbs.gen.nz | Kawasaki Z750GT DoD#0221 The Cave MegaBBS +64 4 643429 V32 | PO Box 2009, Wellington, New Zealand --------------------------------------------------------------------------
woods@eci386.uucp (Greg A. Woods) (12/13/90)
In article <1990Dec10.072439.7591@cavebbs.gen.nz> clear@cavebbs.gen.nz (Charlie Lear) writes: > I have been very kindly offered a Seagate ST4096 to replace it. Obviously > it has a larger capacity and different geometry from the CDC. Therefore it > is not supported directly by the firmware. The 3b2 firmware doesn't directly support any drives in particular. There is a drive type field in the vtoc, but so far as I can tell, it only tells prtconf and perhaps dgmon to spit out some arbitrary thing. The only thing the firmware does is to assume it can find a vtoc on every drive. I used type 11 for the Maxtor 1140, and prtconf magically showed a "135 Megabyte Disk". I found that out by trying several different types on my second drive, re-booting to check what each type showed. > Running SysV 3.2 and using a current idtools disk, would I be able to > format it to 80MB or would I have to de-rate it to 925 cyls and call it > a CDC? Just tell idtools the true geometry of the disk, and off you go! Actually, since I'm not familiar with the ST4096 drive, and I can't find my list of parameters, be careful about formatting beyond 1024 cylinders. I don't think there's a problem with the driver handling more than 1024 cylinders, but I can't look at the header files just now either. ST-506 limits you to 15 heads, of course. Remember to use 512 byte sectors, and 18 s/track (since that's not really part of the geometry, but rather a controller parameter, though it does utilise the maximum number of bits per track allowed by the ST-506 standard recording format). You could get slightly more formatted storage by useing 1kb sectors, but I wouldn't recommend that, and it doesn't really gain much either. > Please post; I'm interested in any experiences people have had in putting > non-ATT-listed disks in 3B2's. I saw a thread a month or so back about > using a Maxtor XT1140 120MB disk, but didn't pay a lot of attention as the > New Zealand list price for an 1140 is NZD$5546 (USD$3383). For those bucks > I would rather write off the 3B2 and buy a 600MB disk and 16-port card > for my 386... nahh, I couldn't write off the 3B2. I'd rather keep it going > and reduce the 386/iX mob to inCoherent rage... 8-) Yup, that was probably me. I have/had a pair in my 3b2/400 (which has been reduced to little more than slage by lightning), and they seemed to work fine, though they excersise the id(7) driver heavily (it misses the odd interrupt, and has to re-cal the drive, and there is a partial fix available). Well, I don't think the 1140's are that much any more, but yes, the last time I saw a list price, they were ~$4,000(CDN). I recall that they were ~$7,000(US) when first announced. Anyway, I bought my first one surplus (but new) for a mere $700 about 3 years ago! They are a little more common on the used markets these days, since not many people who want big (only 120Mb formatted!) drives are still using ST-506. Of course you can always get a SCSI host adapter, 3.2.{1|2|3}, and then buy some SCSI disks! Just don't upgrade that 386! :-) -- Greg A. Woods woods@{eci386,gate,robohack,ontmoh,tmsoft}.UUCP ECI and UniForum Canada +1-416-443-1734 [h] +1-416-595-5425 [w] VE3TCP Toronto, Ontario CANADA Political speech and writing are largely the defense of the indefensible-ORWELL
friedl@mtndew.Tustin.CA.US (Stephen J. Friedl) (12/20/90)
[ I'm way behind on netnews, sigh ] Those wanting to add an ST-506 hard disk to their 3B2 can send me their USmail address and I'll send along a photocopy of an article I wrote for the _3B Journal_ a year or so ago. I cover everything: background, cabling, formatting, how to get idtools, etc. Anyway, onto the note at hand: Greg Woods writes: > The 3b2 firmware doesn't directly support any drives in particular. > There is a drive type field in the vtoc, but so far as I can tell, it > only tells prtconf and perhaps dgmon to spit out some arbitrary thing. > The only thing the firmware does is to assume it can find a vtoc on > every drive. I used type 11 for the Maxtor 1140, and prtconf > magically showed a "135 Megabyte Disk". I have really torn apart the monitor firmware and can find nothing that this drive type is used for except as an index into the edt_data file, and there is *no* magic meaning associated with any particular number. Once indexed into the edt_data file, /etc/prtconf looks at the drive's abbreviation (say, HD72) and literally does an atoi() function on the part after the digits to get the number of megabytes. If you feel motivated you can edit the edt_data file and give your current drive abbreviation "HD300" and /etc/prtconf will report "300 Megabyte drive". You might want to try this while demo-ing your machine for sale :-) > I don't think there's a problem with the driver handling more than > 1024 cylinders, but I can't look at the header files just now either. I am certain that the driver can go beyond 1024 cyls, as Congruent sells a 170MB Priam drive formatted to something like 1224 cyls (I've installed a couple of these). I am *almost* certain that idtools won't go beyond 1024 cylinders, and a moderately reliable rumor is that special hardware is required to format these driver for a 3B2. > You could get slightly more formatted storage by useing 1kb sectors, > but I wouldn't recommend that, and it doesn't really gain much either. Has anybody ever tried this? My skimming of the HD driver source shows that it the sectors/track and bytes/sector parameters *are* used from the PD sector, but the driver is otherwise so terribly hardcoded that I would not be surprised to find that nobody ever tested it with nonstandard params. Anybody? > Well, I don't think the 1140's are that much any more, but yes, the > last time I saw a list price, they were ~$4,000(CDN). If you have a Maxtor 1140 and are using devtools, you gotta get idtools. There were fixes made in idtools specifically made to deal with problems in the 1140: this info is from a very reliable source. Steve -- Stephen J. Friedl, KA8CMY / 3B2-kind-of-guy / Tustin, CA / 3B2-kind-of-guy +1 714 544 6561 / friedl@mtndew.Tustin.CA.US / {uunet,attmail}!mtndew!friedl Why not add Hollerith fields to printf?