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101090 discussions

SA4000 [was: Disc drive READY output -- any standards?]

by tshoppa＠wmata.com

Chuck writes: On 18 Jan 2011 at 14:18, Shoppa, Tim wrote: >> Isn't it wonderful the way the pendulum swings? First parallel >> cylinder select (e.g. SMD and other bus and tag type address >> interfaces), then step in/out cylinder select (e.g. >> SA4000/SA1000/ST-506) and serial cylinder select (e.g. ESDI), then >> parallel cylinder select (e.g. IDE/ATA/SCSI), then serial cylinder >> select (e.g. SATA). > It would seem to be more a matter of "smarts on the disk drive" than > anything. IDE/SCSI and SATA all have controllers on the drive and so > have no dedicated signal lines for positioning. In particular > IDE/SATA LBA and SCSI don't require any knowledge of the drive > geometry, other than the sector size and the total number of sectors. > > with ST506/412 and ESDI, the "smarts" were still external to the > drive. There's a difference between what the interface doesn't require a drive To do, and what the most common drive implementations actually do. (I do agree that IDE LBA and SCSI, allowing a disk to be addressed as a "big bunch of blocks", are substantially more sophisticated than purely Physical interfaces.) You might be surprised at how smart many drives were even though they were Using the "not so smart" ST1000, ST-506 or floppy interfaces. e.g. the cabling may only have "Step in" and "Step out" but on the drive the drive itself is counting which cylinder its in to apply appropriate precompensation. E.g. LSI Shugart floppy drives. Any ST-506 non-stepper-motor drive knew what cylinder it was on thanks To internal logic. The SA1000 explicitly defined "buffered step mode" whereby the step Commands on the interface could come in way faster than the physical stepper Could move, and a counter on the drive played out the steps later. So on The very first implementation, the drive was already smarter than the interface Would imply. Tim.

15 years, 5 months

SA4000 [was: Disc drive READY output -- any standards?]

by thomas.gardner＠sbcglobal.net

> Date: Tue, 18 Jan 2011 09:13:08 -0600 > From: Jules Richardson <jules.richardson99 at gmail.com> > Subject: Re: SA4000 [was: Disc drive READY output -- any standards?] > To: General Discussion: On-Topic and Off-Topic Posts > <cctalk at classiccmp.org> > Message-ID: <4D35AE04.7070905 at gmail.com> > Content-Type: text/plain; charset=ISO-8859-15; format=flowed > > Tom Gardner wrote: > > I believe it was the first HDD of any sort to use a floppy disk type of > > interface. It was followed by the SA1000 interface, which in turn > > became the ubiquitous industry standard ST506 interface. Since it was > > first, it is not surprising that it had problems, > > many of which it inherited from the Shugart floppy interfaces > > it was trying to resemble so as to reduce design in times. > > Was it really done that way because it was supposed to look just like a > big floppy at the interface level? That is my understanding from the folks at Shugart who did it. >Is that actually documented somewhere? Possibly, how important is it to find it on paper? It was explicitly stated as an objective of the next generation, SA1000, "Command signals for the SA1000 use the same pin configuration as its floppy counterpart. Data signals are handled through a different data separator because of the higher transfer rates" ED 9/13/1979 > What would be needed to add a parallel address interface? <snip> Probably could make it look like an SMD interface with a microcontroller. Tom

15 years, 5 months

SA4000 [was: Disc drive READY output -- any standards?]

by tshoppa＠wmata.com

Jules asks: > What would be needed to add a parallel address interface? I believe that could be called the WD1003 :-) In terms of cabling economy parallel cylinder select has some big disadvantages. Not that step-in-step-out cylinder select is awful efficient after you get to having multiple drive systems either (thus ESDI which used similar cabling but much more efficiently). Isn't it wonderful the way the pendulum swings? First parallel cylinder select (e.g. SMD and other bus and tag type address interfaces), then step in/out cylinder select (e.g. SA4000/SA1000/ST-506) and serial cylinder select (e.g. ESDI), then parallel cylinder select (e.g. IDE/ATA/SCSI), then serial cylinder select (e.g. SATA). Tim.

15 years, 5 months

SA4000 [was: Disc drive READY output -- any standards?]

by thomas.gardner＠sbcglobal.net

> Date: Sat, 15 Jan 2011 17:21:34 +0000 (GMT) > From: ard at p850ug1.demon.co.uk (Tony Duell) > Subject: Re: Disc drive READY output -- any standards? > To: cctalk at classiccmp.org > Message-ID: <m1Pe9or-000J43C at p850ug1> > Content-Type: text/plain > > > > For pure bad deisgn, nothing beats the Shugart SA4000 hard disk. > > > > I have one of those. It has all the warts of an early design. > > Except it wasn't an early design. OK, it was an early-ish wincheaster, > but stepper motor controllers are much the same whatever you sue them > for. The problems were known about and could have been avoided. > > -tony I believe it was the first HDD of any sort to use a floppy disk type of interface. It was followed by the SA1000 interface, which in turn became the ubiquitous industry standard ST506 interface. Since it was first, it is not surprising that it had problems, many of which it inherited from the Shugart floppy interfaces it was trying to resemble so as to reduce design in times. Tom

15 years, 5 months

Long term publicly accessible backups [Was: Uncorrupted A/UX 3.1 Update]

by jfoust＠threedee.com

At 09:53 AM 1/18/2011, Shoppa, Tim wrote: >Now posting it to a binary warez newsgroup, I don't see much harm in that. Worst case, somebody might complain that what you're posting is not illegal or a copyright violation and therefore you shouldn't do it. Thank you for starting my day with a good belly-laugh. - John

15 years, 5 months

Long term publicly accessible backups [Was: Uncorrupted A/UX 3.1 Update]

by tshoppa＠wmata.com

Clint writes: > For a while now I have been pondering Usenet as a long term, offsite, > distributed backup facility. Most of the premium servers are over two > years of archive, with pretty decent reliability. Spot checks of > files posted over two years ago still indicate 100% article availability. > Basically, I propose we select a low-traffic group which is available on > most premium servers, and start posting software/documentation to it in a > standard rar/par2 format. And somewhat standardized naming conventions. > If a file was posted two or three times over the span of a month, then > reposted every year we can be almost assured the files would be available > to enthusiasts for many years to come. Seems to me, not that different than Cantor and Siegel's Usenet Spam. As in, it's technically possible to do something, so it's OK to do it. Misusing Usenet, not a good idea. Now posting it to a binary warez newsgroup, I don't see much harm in that. Worst case, somebody might complain that what you're posting is not illegal or a copyright violation and therefore you shouldn't do it. Tim.

15 years, 5 months

Fwd: [rescue] PDP flip chips and memory boards, many lbs. worth

by paul_koning＠Dell.com

Figured this might be of interest... paul Begin forwarded message: > Date: January 17, 2011 9:23:22 PM EST > To: pkoning at equallogic.com > Subject: Fwd: [rescue] PDP flip chips and memory boards, many lbs. worth > > Forwarded in case you know anyone who collects real PDP iron out there... > > john > > > Begin forwarded message: > >> Date: 17 January 2011 20:21:26 EST >> To: The Rescue List <rescue at sunhelp.org> >> Subject: [rescue] PDP flip chips and memory boards, many lbs. worth >> Reply-To: The Rescue List <rescue at sunhelp.org> >> >> Some of you here know that I recycle old PC motherboards, etc. though >> whenever possible I try to divert anything valuable/historical out of >> the melt-it-down pile. >> >> I have many pounds, well over 100lbs., of DEC PDP "flip chip" modules. >> >> I have to charge for them, but would like to sell all of them, all at >> once, to 1 person if possible, at a per-lb price ($8 per lb). Given >> that these flip chip modules are not very heavy this works out to well >> under $2 each, I think. >> >> Some are in original plastic shrink wrap, but most are not, and have >> been exposed to moisture but are otherwise complete; some have had the >> resistors or capacitors on them "weep" which means they would have to be >> replaced by someone competent with a soldering iron. >> >> A random listing of the few that I pulled out: >> >> A123 >> A206 >> A207 >> G728 >> K012 >> K026 >> K028 >> K123 >> K124 >> K134 >> K161 >> K202 >> K210 >> K303 >> K683 >> M113 >> M1502 >> M155 >> M207 >> M230 >> M502 >> M652 >> M7264 >> M783 >> M7941 >> M920 >> M974 >> >> There are many more. >> >> Are there any PDP collectors on this list - I know there used to be but >> perhaps this stuff is just too old these days. >> >> Cordially >> >> Patrick Giagnocavo >> patrick at zill.net >> _______________________________________________ >> rescue list - http://www.sunhelp.org/mailman/listinfo/rescue >

15 years, 5 months

HP 8018A heath sink getting hot

by hp-fix＠xs4all.nl

I acquired a HP 8018A serial data generator, a very nice piece of equipment. But after a little time the power supply heath sink is getting hot about 70 degrees Celsius (158F). I'm not sure if that is normal, anyone who can help me with this ? -Rik

15 years, 5 months

Looking for: Sun 3/150 or 4/150

by derschjo＠mail.msu.edu

Title says it all; I'm basically looking for a VME-based Sun workstation with 5 or 6 slots -- something that's a nice middle ground between the cramped 3-slot machines and the huge 12 and 16-slot ones. It doesn't have to be complete or running, but a working power supply would be helpful... I'm trying to find a suitable host for my Symbolics UX400 (a VME-based lisp coprocessor for old Sun machines), and the Sun 3/140 I have doesn't seem to be able to keep the UX400 cool enough (it crashes quite frequently). Anyone (preferably local to Seattle) have something that fits the bill going spare? I can trade a bunch of Sun3 hardware :). - Josh

15 years, 5 months

Still looking for LaserJet lower cassette

by charlesmorris800＠centurytel.net

I'm still trying to locate the "Optional Lower Cassette" for my HP LaserJet IIp+ (that holds 250 sheets of paper and fits underneath the printer (instead of feeding them 20-30 at a time through the front door). Anyone have a "parts" IIp from which I can buy the cassette & paper tray? thanks Charles

15 years, 5 months

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