test-drb October 2005

test-drb@ccmp.vtda.org

264 participants
655 discussions

by jwest＠classiccmp.org

I have the keyswitch from a 2105/2108/2112 type system available, snagged it >from the trash. This is the key switch style that has an "R" position (ie. an electronic keyswitch, not just a mechanical one). This is the 3 or 4 layer discs with a cord and molex-style connector that goes to the power supply. No key, no keyhole, just the switch assembly itself with cord and connector. I have no M machines with that style keyswitch (mine have all been 'upgraded' to the mechanical keyswitch). Price... 1xpostage+postage. I would expect postage to be like... 2 bucks. Jay

18 years, 6 months

Another P/S question

by compoobah＠valleyimplants.com

Whilst waiding through the IRISes power supply, I found another exploded paper cap. (PS date 1985). Is this likely normal, or should I look somewhere else (don't have a working scope). Would the failure of one cap put more stress on the remaining ones? When I get the machine working, I hope to have something interesting to report, but I have no confirmation yet. ScottQ

18 years, 6 months

Waht is an MC1806 ?

by dwight＠ca2h0430.amd.com

Hi Tony I would guess that it is the same as a TI 806 DTL. I don't have a data book for that but it seems like I found one on the web someplace when I was looking at some of the DTL's in my Nicolet computer. Dwight >From: ard at p850ug1.demon.co.uk > >The Subject: line says it all really, but perhaps I should give a little >more explanation. > >I am working on an HP59405, which is the HPIB interface for the HP9830 >'calculator'. On the PCB are 2 chips which cross to something called an >MC1806. This is not in any of my Motorola databooks. > >What I have determined (I think) so far : > >1) 14 pin DIL package, power on 14, ground on 7 as usual. > >2) Seems to be a quad 2-input device, pinout as the 7400 -- that is, >inputs on 1 and 2, output on 3, etc. > >3) Seems to be DTL in that the output directly drives the base of an NPN >transsistor, the emitter of which is grounded. > >4) The most logical (!) function would be a quad 2 input NOR gate. Maybe >an AND gate? > >Does anyone have a databook that lists it? > >-tony > >

18 years, 6 months

Yet another idea for recovering the data from Series80 tapes

by dwight＠ca2h0430.amd.com

>From: "Vassilis Prevelakis" <vp at cs.drexel.edu> > >ard at p850ug1.demon.co.uk (Tony Duell) wrote:... >> Hmmm. I thought it was where the taps stuch to itself, or to the drive >> belt, when the catridge was stored. In which case your idea might not >> help much. > >Aha! There goes my original hypothesis. Well, that is relatively easy to >check. I took apart two old tapes and found the following: > >Assuming that the tapes were rewound before storage, there are two >stretches of weakened magnetic coating on both tapes I looked at; the first >was short while the second longer. These correspond to the length of tape >in contact with the drive belt > Hi It sounds like the belts should still have any data that was on the tape for those stretches. Reading may be a little difficult but the information is still in the magnetic media. Dwight

18 years, 6 months

Chicago-area DECies?

by ISC277＠CLCILLINOIS.EDU

Hey, I was just wondering if any of my fellow DECies on this list live in the Chicago area, I know there were quite a few DEC shops around here back in the day.

18 years, 6 months

installing new ethernet address equipment with VMS 6.1

by Rinaldo.Eversdijk＠stork.com

Hey, the MAC address doesn't tell me anything, but the ethernet address I'm talking about is printed on the back of the equipment and is like; 08-00-2B-BF-94-C4 The following items we want to replace have such an address; DEC server VXT2000+, model VX20A-EA DEC server 700 COMM 8 port, model DSRVW-ZA DEC server 250, model DSRVP-A And of course our DEC3000 (rackmounted model: PE43B-XA, series BA47R) itsself has an ethernet address. As stated before; we are running on VMS version 6.1 and our system is 11 years old, but still running smooth. We have now bought 'new' 2nd hand items for replacements in case one of all items run down so we can replace it immediatly, but we are now only missing the protocol to do so for the ethernet address items. Hope this helps for solving the installation problem. Rgds, Rinaldo -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Witchy Sent: maandag 24 oktober 2005 14:13 To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: installing new ethernet address equipment with VMS 6.1 On Mon, October 24, 2005 11:41 am, Rinaldo.Eversdijk at stork.com said: > > Does anyone know how to install, on a alpha computer (DEC3000) running > with VMS version 6.1 software, the same equipment with a new Ethernet > address? Which address do you mean, the MAC address of the ethernet hardware or a different DECnet address? The MAC address is burned into the hardware and only gets changed when the machine is in a cluster IIRC, and changing the DECnet address is different from Phase IV DECnet to DECnet/OSI. If you can give us some more information it'll help. Cheers, -- adrian/witchy Binary Dinosaurs creator/curator www.binarydinosaurs.co.uk - the UKs biggest home computer collection? -------------------------------------------------------------------------- DISCLAIMER: This e-mail and any attachment(s) sent with it are intended exclusively for the addressee(s), and may not be used by, opened by, passed on to, or made available for use to, any person other than the addressee(s). Stork rules out any and all liabilities resulting from any electronic transmission.

18 years, 6 months

Yet another idea for recovering the data from Series80 tapes

by vp＠cs.drexel.edu

"Joe R." <rigdonj at cfl.rr.com> wrote: > FWIW I tested about a dozen tapes a few years ago and about 4 failed > on the first pass, about that many failed in the next few days and > only one lasted a week. The tapes stick unto themselves, so it is a good idea to unwind them slowly rather than perform a retention (CTAPE) which is a violent and abusive treatment for a tape that is ready to fall apart. Whether you (think you) can afford two data extraction passes (vs one pass) on a given tape *will* affect the strategy used. In the one-pass case you have to salvage all you can from both tracks, while in the second case you can rewind the tape (at the slow reading speed, of course) and have a go at the second track. The HP-85 tapes (and their 98xx cousins) are NOT serpentine: to read track 2 you rewind to BOT and start reading using the second head. Unfortunately the read/write IC (1820-2418) on the HP-85 can only deal with one head at a time (only one DIO pin), so to employ the one-pass strategy, you either have to wire another 1820-2418 strapped to read track two, or you have do the analog (audio) recording I suggested initially. > They DO use the same tape so they must be compatible. I don't know about > the track spacing but I would think they would be the same. Bad news. I checked the specs (TechData brochures from hpmuseum.net) and came up with this table for read/write speeds HP 9825 22ips HP 9835 22ips HP 9845 22ips (didn't find any data, but I assume its 22 ips) HP 85 11ips HP 9815 10ips So there goes any hope of cassette data interchange between the Series80 and the rest of the HP line. :-( Apparently the HP-85 was a cheapo solution vs the 98[234]5 line. The speed was slower and while this does not reflect on the total capacity of the drive (around 240Kb), its access times are worse. This was a surprise to me as I would have thought that HP would want to have some data exchange capability between the newer low-end HP-85 and its high-end models (after all they were expected to co-exist in the same environments). > It should be > easy enough to check with some MagnaSee. I THINK that's the name of the > liquid that you put on mag tapes/cards to see the magnetic tracks. I have a > can of it around here somewhere but no idea where it's at at the moment. I have been trying to get this thing for ages, and I couldn't. In the end I found this www.sprague-magnetics.com/library/sprgmag.pdf which works the same way. Initially I thought I could simply spray the stuff on the tape and optically read the bits, but its too messy. > Actually that sounds like a GOOD idea. Ratty looking HP 85s are readily > available. I'd take one of those and take out the tape drive ribbon cable > and replace it with real wires then add some test points to it and maybe > cut some sections out of the case to allow access to it's inards and make a > test platform out of it. My advice is to go for 9915As I have seen them go for next to nothing on eBay, and even then remain unsold. Apparently people do not realize that these are Series 80, or they are discouraged by the lack of screen and (most importantly) keyboard! I am also afraid that by creating the series80.org site, I caused an increase in the prices of Series80 machines, but with the hpmuseum.net slowly making all this info available anyway, I do not feel so guilty any more :-) **vp PS I found another metric screw up: In the 9835TechData-5953-0982-12pages-Oct78.pdf file in hpmuseum.net the length of the tape is given as 426.7 METERS, followed by the more reasonable 140ft (the HP-85B spec sheet gives the length of tape as 43m or 140ft). BTW2 On the HP-85 the rewind time (end-to-end) is 29 sec. When I was checking an early capstan repair and did a CTAPE (which does a fast forward to EOT and then a fast rewind to BOT), it felt like that thing was taking forever (probably it took longer because I was watching over it :-)

18 years, 6 months

Paper as History Logging medium: new Book

by allain＠panix.com

How about this for a new book? "Digital Retro : The Evolution and Design of the Personal Computer" by Gordon Laing Amazon.com informs me that it was published just three weeks ago. Wonder if anyone here has seen it yet? A reviewer says its set up as Amstrad to Zenith, with photos, might be kind of fluffy. John A.

18 years, 6 months

Wildcat 4

by mokuba＠gmail.com

Anyone ever hear of / use wildcat 4? I just found an old copy my dad pirated + a sysop manual he ripped off of someone in a box of books he had... Anything anyone can tell me about it? :) Heh, oldskool BBS piracy in my own hands :)

18 years, 6 months

Commodore 128 computers available in Summit, New Jersey

by vcf＠siconic.com

Sorry, I lost the details, but Lou Helfer in Summit, New Jersey, has some Commodore 128 systems to give away. Several I think. Contact Lou for details. Reply-to: lhelfer at comcast.net -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

18 years, 6 months

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test-drb October 2005