elias@batcomputer.tn.cornell.edu (Doug Elias) (12/23/88)
Has anyone successfully hung a 2nd ESDI (either 30M or 70M) drive off a 310 without recourse to an expansion-box? If so, have you had to do anything with your powersupply in order to make it work, and what kind of cabling scheme did you use? Thanks. -- ____ Internet: elias@tcgould.tn.cornell.edu _|_)oug USmail: Cornell Theory Center (_| 265 Olin Hall,C.U.,Ithaca,N.Y.,14853-5201 (_|__ MaBelle: 607-255-8686
randy@chinet.chi.il.us (Randy Suess) (12/23/88)
In article <7057@batcomputer.tn.cornell.edu> elias@batcomputer.tn.cornell.edu (Doug Elias) writes: >Has anyone successfully hung a 2nd ESDI (either 30M or 70M) >drive off a 310 without recourse to an expansion-box? If so, > I believe you mean ST506, not ESDI. Unless you have a non-standard controller on your 3b2. Yes, you can get any PC Klone type hard disk that is 1024 cylinders - 8 heads or less, put it in a standard drive cabinet/power supply meant for PC's, run stock 34 / 20 pin ribbon cables to the jacks in the back of the 3b2, set the drive selects properly and remove the internal drive terminator, use the DEVTOOLS diskette to init the external drive, and you are up and running. -- Randy Suess * But don't underestimate raw, frothing, * randy@chinet.chi.il.us * manic hardware. -barry shein *
friedl@vsi.COM (Stephen J. Friedl) (12/29/88)
In article <7259@chinet.chi.il.us>, randy@chinet.chi.il.us (Randy Suess) writes: > Yes, you can get any PC Klone type > hard disk [for the 3B2] that is 1024 cylinders - 8 heads or less... While there does indeed seem to be a limitation on 1024 cylinders, the 3B2 is happy to use up to sixteen heads (indeed, the stock CDC drives that ship from AT&T have nine heads). Congruent Technologies appears to have found a way to format a drive with > 1024 cylinders, but we've not been able to do so. The formatting utilities, called `idtools' (previously `devtools'), are available in the 3B2 Maintenance Reference Manual, and it is well worth the ~~$60 from AT&T. Send mail if you want the info. Steve -- Stephen J. Friedl 3B2-kind-of-guy friedl@vsi.com V-Systems, Inc. ****Hi Mom!**** attmail!vsi!friedl Santa Ana, CA USA +1 714 545 6442 {backbones}!vsi!friedl -------Nancy Reagan on Usenix in San Diego: "Just say *go*"-------
len@netsys.COM (Len Rose) (12/30/88)
I have to assume it's just a driver loaded that enables the controller to access the extra cylinders.. I always thought that the controller chip was the limitation..I am trying to get a data sheet on the controller (NEC 7261) for another project .. I might guess that also like the original driver, Congruent may be stealing an unused bit somewhere on the controller chip.. Until I see a data sheet,no way to tell. The project I mentioned was re-doing the driver so that one could have 4 drives * running off the internal controller (4 drives each 8 heads/1024 cyls) without having to resort to adding expansion disk controllers. The hardware is there already,and I suspect the driver should be easy. I believe there was some mention of this in an old issue of the 3B Journal,but I don't remember which issue. * Example: Micropolis 1325 (8 hds/1024 cyl)
pfales@ttrde.UUCP (Peter Fales) (01/01/89)
In article <982@vsi.COM>, friedl@vsi.COM (Stephen J. Friedl) writes: > In article <7259@chinet.chi.il.us>, randy@chinet.chi.il.us (Randy Suess) writes: > > > Yes, you can get any PC Klone type > > hard disk [for the 3B2] that is 1024 cylinders - 8 heads or less... > > While there does indeed seem to be a limitation on 1024 cylinders, > the 3B2 is happy to use up to sixteen heads (indeed, the stock CDC > drives that ship from AT&T have nine heads). Congruent Technologies > appears to have found a way to format a drive with > 1024 cylinders, > but we've not been able to do so. Sorry, this is pretty sketchy, but... The earliest models of the 3B2/300 (possibly 310?) did only support disks with eight heads or less. The following simple modification will allow an early model 3B2/300 to use more than eight heads: DISCLAIMER: I have done this myself and seen it work, however, NEITHER I NOR AT&T CAN TAKE ANY RESPONSIBILITY FOR ANY DAMAGE TO YOUR SYSTEM AS A RESULT OF ATTEMPTING THIS MODIFICATION. My notes don't indicate what this chip is, but it is right next to the Hard Disk controller chip in this physical location. | | v --------- ------------- | | | | | 12|-+ | | <--- NEC Hard Disk Controller Chip | | | | | 1) Isolate Pin 23 | | | | | 2) Add Wire from pin 27 to pin 12 | | | | | | | | | | --------- | | | | | | | | | | | 27|------+ | | | | | | 23|--X | | | | | | ------------- | | | +--------------------+ -- Peter Fales AT&T, Room 2F-217 200 Park Plaza UUCP: ...att!ttrde!pfales Naperville, IL 60566 Domain: pfales@ttrde.att.com work: (312) 416-5357
len@netsys.COM (Len Rose) (01/01/89)
The problems was corrected once the 310 was released.
--
len@netsys.com
{ames,att,rutgers}!netsys!lenfriedl@vsi.COM (Stephen J. Friedl) (01/02/89)
In article <806@ttrde.UUCP>, pfales@ttrde.UUCP (Peter Fales) writes: > > The earliest models of the 3B2/300 (possibly 310?) did only support disks > with eight heads or less. The following simple modification will > allow an early model 3B2/300 to use more than eight heads: > > [simple mod deleted] I can provide some additional information on the 3B2 hard disk system that might help with some understanding here... The disk controller chip on the 3B2/{300,310,400} is the NEC 7261, and it has two drive-select lines plus three head-select lines. Fully decoded, this provides four drives of eight heads each. The CDC Wren II drives that AT&T uses have *nine* heads, so AT&T -- in the 310, at least -- decided to use one of the drive select lines as a head select. So, the controller can now talk to two drives, each having sixteen heads. You may imagine that the driver software has to do some odd stuff to make this happen, and you're not too far off. >>>>> the following is *total* speculation on my part. <<<<< I would guess that Peter's mentioned modification is doing what is described above -- routing the controller's second drive-select line to the interface's fourth head-select. When they came out with the /310 and the /400, this modification was part of the standard system. I would also speculate that this mod won't work on an original /300 with original software, because the drivers would not have known how to do the diddling with the lines -- everything since (at least) SVR2.0.4 has it standard in the IDISK driver. Steve -- Stephen J. Friedl 3B2-kind-of-guy friedl@vsi.com V-Systems, Inc. I speak for me only attmail!vsi!friedl Santa Ana, CA USA +1 714 545 6442 {backbones}!vsi!friedl -------Nancy Reagan on Usenix in San Diego: "Just say *go*"-------
rct@occrsh.ATT.COM (01/11/89)
Peter Fales mentioned a quick hardware hack to allow old 3B2/300 motherboards (CM-190A, artmaster 5 and older) to handle up to 16 heads/drive. The "white wire" should be run from pin 27 of the NEC7261 to pin 3 of the LS14, rather than to pin 12 of the LS14 (third pin on the left, rather than the third pin on the right). Here is a corrected sketch of the modification that I cribbed from Peter's article: I NOR AT&T CAN TAKE ANY RESPONSIBILITY FOR ANY DAMAGE TO YOUR SYSTEM AS A RESULT OF ATTEMPTING THIS MODIFICATION. My notes don't indicate what this chip is (LS14 as mentioned earlier -- ed.), but it is right next to the Hard Disk controller chip in this physical location. | | v +-----------------------------+ | --------- ------------- | | | | | | | +--|3 | | | | <--- NEC Hard Disk Controller Chip | | | | | 1) Isolate Pin 23 | | | | | 2) Add Wire from pin 27 to pin 3 | | | | | | | | | | --------- | | | | | | | | | | 27|--+ | | | 23|--X | | ------------- Enjoy! I tried it out on an old AM5 motherboard and it DOES work! --Bob Tracy AT&T Network & Data Systems Oklahoma City Works att!occrsh!rct (405) 491-4577