test-drb December 2007

test-drb@ccmp.vtda.org

215 participants
420 discussions

by legalize＠xmission.com

OK, with my new Origin 2000 machines, I was thinking that I could use these SGI drives+sleds that I had purchased previously, where the seller said they would work in Onyx2/Origin machines. However, while the sleds appear compatible, the drive interface is not. Is there any online guide that compares the different drive sled designs for SGI machines so that I can compare what's being offered on ebay to identify the machines that can use it? For instance, my drives have a high density connector that is only about 1" long, but the Origin 2000 has a high density connector that looks to be about 2-2.5" long. Is my only recourse to scrape through individual manuals to try and find diagrams? -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

17 years

Max configuration of SGI Origin 2000/Onyx2 architecture

by legalize＠xmission.com

OK, we talked earlier about how high this architecture could go and there was some mention of 256 and 512 processor systems. However, I just stumbled across a press release at LANL describing their installation of a massive 6144 processor system consisting of 48 sets of 128 nodes all arranged as a giant supercomputer: <http://www.lanl.gov/news/index.php/fuseaction/home.story/story_id/1846> This machine was decomissioned in 2004: <http://www.lanl.gov/news/index.php/fuseaction/home.story/story_id/5836> Something tells me that I won't be able to afford 6144 processors without a grant and a lot of scrounging :-) -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

17 years

cctalk Digest, Vol 52, Issue 34

by compoobah＠valleyimplants.com

On Dec 16, 2007, at 11:19 PM, Richard wrote: >> OK, with my new Origin 2000 machines, I was thinking that I could use >> these SGI drives+sleds that I had purchased previously, where the >> seller said they would work in Onyx2/Origin machines. However, while >> the sleds appear compatible, the drive interface is not. >> >> Is there any online guide that compares the different drive sled >> designs for SGI machines so that I can compare what's being offered on >> ebay to identify the machines that can use it? There is, sadly it is at the SGI Addict (www.sgiaddict.net) which is inconsistently up. This is most useful for the older sleds with integral connectors, modern SGI sleds are (I believe) one of three types: O2 (wouldn't come close to fitting), Octane/Origin200/000/Onyx2 (works), and Origin300/000 >> >> For instance, my drives have a high density connector that is only >> about 1" long, but the Origin 2000 has a high density connector that >> looks to be about 2-2.5" long. >> A drive with a 1" long connector very similar to a SCSI SCA connector is probably FC (Fiber Channel). If you have a newish Sun (Blade 1000/2000 era) you can check, as the main interface in these is FC. The FC drives I have (Seagates) have a model number ending in FC. Some of the SGI Vaults/InfiniteStorage arrays do use FC disks, so it's possible that these came out of one of those. Sadly, I'm not sure that the Qlogic FC interfaces are bootable, so you might not be able to use them as a system disk.

17 years

Homebrew Drum Computer (magnetic heads)

by bnansel＠bigpond.net.au

With a sharp enough v-notch and very gradual abrasion from the outside, is should be possible to make the gap less than one thou. This is sort of the inverse of the way they made the point contacts for the first transistor at Bell Labs. -Bobby > >So, aside from the mumbles, does this sound like a workable plan? > > Ah no. the gaps have to be narrow less than .001". that hs been done > two peice ferrite heads (half beads) with oe side of the magnetic > circuit > filled with .001" thick brass shim stock. > > Or you could pull the heads from a number of old floppies. > > The 14" platter is a good source for media. > > > Allison >

17 years

Homebrew Drum Computer (magnetic heads)

by bnansel＠bigpond.net.au

RIght. But it would be plenty big for registers, say. Those delay lines have 4.5MHz bandwidth (I think...), so they ought to be able to handle a short series of pulses; 16 bits should be easy, and 32 might work, too. An analog guru could probably squeeze more in 64us. -Bobby > > ... > >The delay line I was sgggesting for use as a computer memory > device is a > >glass block wioth untrasonic transducers on it. It's got a delay > period > >of almost one complete line-time, and is used to store one of the > >chromanace signals as part of the PAL decoding process. > > I don't know about PAL but one line for NTSC is only 63us and thats > not enough delay. > > Computers that used delay lines were in the milliseconds range as they > needed to store a lot of bits/digit/words. > > > Allison >

17 years

Homebrew Drum Computer Delay Lines

by bnansel＠bigpond.net.au

I've come across a reference to a reverb unit made with a garden hose, speaker, and microphone. Would something as bone-headed as this work as a data delay line? I've read that mercury was used in delay lines because it was a better impedance match with quartz transducers, but wouldn't water work nearly as well? Everything would need to be kept at a constant temperature, and no doubt there would be some dispersion of the compression waves. It's my understanding that a lot of materials were tried for delay lines, but that mercury was the "best." Magnetostrictive delay lines are attractive, though I hear they are more than a little microphonic. I notice that most magnetostrictive delay line designs use the transducers to generate torsional waves, which apparently suffer less from dispersion and have a slower propagation speed to boot. The pictures I've seen show the transductive materials spot welded to the delay wire such that they twist the wire when a magnetic pulse is applied: http://www.science.uva.nl/faculteit/museum/delayline.html Does anybody know how well plain nickel wire would work OK, or would some more exotic like Terfenol-D be required? The delay wire itself need not be magnetostrictive; it's just the storage medium. -Bobby

17 years

Small SBC kits for Christmas!

by ajp166＠bellatlantic.net

> >Subject: Small SBC kits for Christmas! > From: "Matt Lichtenberg" <kerobaros at gmail.com> > Date: Sat, 15 Dec 2007 08:21:28 -0600 > To: cctalk at classiccmp.org > >So, every year I like to get myself a little something; this year, I'm >probably going to be getting a new computer (outside the realms of >this list), but I'd also like to get some kind of single-board kit >that I can work on. > >I'd like something along the lines of a ZX-81 kit, although it looks >like those are selling for somewhere around $250, when you can find >one. SpareTimeGizmos' Elf 2000 kit also looks fantastic, but I don't >have an 1802 or an 1861 to use in the thing, and I'd rather not hunt >any down. (If anyone wants to get rid of theirs, though, let me know. >*grin*) The Elf200 is excellent and there is a yahoo group for it as well. Finding 1802s is generally easy. the 1861 is a different can of worms but Bob solved that with a tiny board that emulates it. See the Spare Time Gizmos site for details. No you can't have mine! >Has anyone seen any similar kits out there? They don't have to be >useful for anything, just fun to play with, and not horribly difficult >to put together. I can solder fairly well, and I'm mean with a >multimeter, but I don't have the money for my own oscilloscope; I just >use other peoples' when they're not looking. Thanks, folks! If you hunt around the net there are SBC of all sorts. Allison >~Matt

17 years

4004 and IC history / was Re: Vintage computer photogallery

by RodSmallwood＠mail.ediconsulting.co.uk

It could be him, but its over thirty years ago and of course remember I him as he was not as he maybe now. I worked for the Terminals Product Line and sold VT100's and LA36's to resellers and OEM's in the UK. The target margin per unit may not have been reached. However the volume was so high and the economies of scale such that over all DEC made lots of profit from what became the industry standard. Rod -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Tore Sinding Bekkedal Sent: 16 December 2007 18:56 To: General Discussion: On-Topic and Off-Topic Posts Subject: RE: 4004 and IC history / was Re: Vintage computer photogallery On Thu, 2007-10-18 at 13:04 +0100, Rod Smallwood wrote: > The design of the VT100 was done by one engineer who I met but I > cannot recall his name. I believe you may be referring to Mike Leis. I snapped a photo of him at a DEC reunion at The Mill: http://gunkies.org/photos/mill/big/img_3513.jpg Amongst other things, he told me that DEC considered the VT100 to be a failure, since it never met the profit margin outlined in the project proposal. The main reason they created the VT100 was because the VT52 was quite hard to mass produce automatically. -Tore

17 years

Homebrew Drum Computer (magnetic heads)

by ajp166＠bellatlantic.net

> >Subject: Homebrew Drum Computer (magnetic heads) > From: Robert Nansel <bnansel at bigpond.net.au> > Date: Mon, 17 Dec 2007 09:31:49 +1030 > To: cctalk at classiccmp.org > >I think I might have a whack at making R/W heads using small ferrite >cores/beads, the kind used in radio work. > >My plan is to string several cores up on a straight brass rod with a >snug fit to their I.D., then bed the whole lot in wax and remove the >rod. Next I'll use an abrasive <mumble 1> to grind a tiny V-notch >from the inside of the cores, taking care not to break through the >outer diameter. > >After removing the cores from the wax I'll wind <mumble 2> turns of ><mumble 3> gauge magnet wire on them, fixed in place with super >glue. Then I would re-bed them in more wax, this time with the coils >down and the internal notches up. The cores would be almost >completely embedded in the wax to provide strength for the fInal >step, grinding a flat very slowly from the outside until the sharp >end of the notch is exposed for each core. This makes the gap. > >I'll remove them from the wax and mount them on <mumble 4> blocks >with <mumble 5> screw adjustments. > >As for the drum part, I think I'll be best off with a disk instead, >perhaps a 14" washing machine platter and spindle from a 3000RPM ><mumble 6> Gonkulator. > >So, aside from the mumbles, does this sound like a workable plan? Ah no. the gaps have to be narrow less than .001". that hs been done two peice ferrite heads (half beads) with oe side of the magnetic circuit filled with .001" thick brass shim stock. Or you could pull the heads from a number of old floppies. The 14" platter is a good source for media. Allison >-Bobby > > >> Fri Dec 14 14:22 Gary Oliver go at ao.com said: >> >> I have a reference somewhere for a drum project from the 40s that used >> what would now be simple machine-shop procedures (assuming one had a >> small drill-mill and lathe) to fashion a small drum of a few k-bit >> capacity. I'll try to dig that out and send it along. I was sort of >> planning to do something along this line myself at some point during >> "retirement" (which won't be for a few years, I suspect.) I've >> acquired >> a few of the components for fabricating the drum and will give it a >> "whirl" some day. I was definitely NOT planning to make a flying head >> device and to keep it simple enough I could fabricate a few heads from >> "first principles."

17 years

KayPro II keyboard schematic?

by ajp166＠bellatlantic.net

> >Subject: Re: KayPro II keyboard schematic? > From: ard at p850ug1.demon.co.uk (Tony Duell) > Date: Sun, 16 Dec 2007 22:17:22 +0000 (GMT) > To: cctalk at classiccmp.org > >> > What was used inside the Kaypro to receive the keyboard data? >> >> Z80 SIO, at least on the -II and -4. > >Drat! It could be async or syunc, since that chip can be configured to >handle eithr format. But I'll be t it's the former. Its async, I posted it was Async, SIO/DART yesterday. It's levels are TTL to save RS232 conversion and power needed for negative supply. It's an easy keyboard to talk to via serial. I have two Kaypros and a spare keyboard. its not rocket science. Allsion > >-tony

17 years

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test-drb December 2007