test-drb March 2017

test-drb@ccmp.vtda.org

188 participants
235 discussions

Looking for windows 1.x for HP-150 touchscreen Also looking for Touchscreen II

by COURYHOUSE＠aol.com

Looking for windows 1.x for HP-150 touchscreen Also looking for Touchscreen II drop me a line offlist. Thanks Ed Sharpe archivist for SMECC In a message dated 3/20/2017 1:06:35 A.M. US Mountain Standard Time, cctalk at classiccmp.org writes: Probably you wanna say "original retail package" :) 2017-03-19 21:54 GMT-03:00 Sellam Ismail via cctalk <cctalk at classiccmp.org>: > I have for sale a complete copy of Windows 1.0 (release 1.01) in the > original retail pricing. Please check out my ad on the VCF forums for > complete info: > > http://www.vcfed.org/forum/showthread.php?56814-Microsoft-Windows-1-0-in- > original-retail-packaging-complete > > Thanks! > > Sellam >

7 years, 4 months

FS: Microsoft Windows 1.0 in original retail package

by sellam.ismail＠gmail.com

I have for sale a complete copy of Windows 1.0 (release 1.01) in the original retail pricing. Please check out my ad on the VCF forums for complete info: http://www.vcfed.org/forum/showthread.php?56814-Microsoft-Windows-1-0-in-or… Thanks! Sellam

7 years, 4 months

LGP-30 Update

by coryheisterkamp＠gmail.com

Hey guys, figured it was time for an update on the LGP-30 resuscitation. Some further detective work found a leaky 1500uF cap in one of the B+ supplies which was causing the 'surging' issue on the scope. For good measure I replaced all six 1500 and 3000uF caps even though ripple was low. Better safe than sorry and if it means pulling that chassis and its covers again, all the better. I attempted to weigh it on my shipping scale, but it only registers to 100 lbs and the indicator flew right past that. There had been a small thermal event in the AC junction box that the twist lock connector mounts to, and I suspect it occurred pre-60's refurb. It's not too surprising as the wiring on the computer side is aluminum and the feed is copper. The box needed replacing but was a unique Hubbell variation of a std 4" box with special ears. I couldn't find anything even close to that at any of the supply houses online, probably because it violates today's conductor fill rules (it's only 1" deep but the socket consumes most of that depth and 75% of the area). I eventually settled on drilling/tapping a standard box and cleaned up the wiring. The sequencer unit is now working correctly after I found an NOS relay to R&R contacts with. The blower is still steady and quiet with its new bearings, and no issues (knock on wood) with the drum after greasing the end bearing, belt and 'tightening' up the tolerances on the timing and short register heads. Some good news- I now have three horizontal lines on the scope, rock solid and where they should be. I can get the occasional pattern for Instruction contents, but Order and Accumulator still aren't reading/writing/displaying. All in good time. http://radar58.com/LGP30/wp-content/uploads/2017/03/lgp.jpg Even better news is that the three timing tracks appear to be intact on the drum and the supporting hardware is working. http://radar58.com/LGP30/wp-content/uploads/2017/03/scope-e1489957963176.jpg (1, 2 and 3 correspond to S1, S2 and S3) Now to investigate those short registers... -Cory

7 years, 4 months

FS: Ampro Little Board P5x, Pro-Log M900 PROM Programmer, Documation D150 Card Reader

by sellam.ismail＠gmail.com

7 years, 4 months

FS: Heathkit ES-400 analog computer front panel

by sellam.ismail＠gmail.com

I have for sale a Heathkit ES-400 front panel (only). Please check out my ad on the VCF forums for full details: http://www.vcfed.org/forum/showthread.php?56811-Heathkit-ES-400-Analog-Comp… Thanks! Sellam

7 years, 4 months

8085 RESET

by witchy＠binarydinosaurs.co.uk

Hi folks, 8085-based phone system weirdness continues and I'm beginning to wonder if the PSU rails are all coming up in time for RESET to go high - given there's 4116 DRAMs in there isn't there supposed to be a proper power up order? While I look at using a 20-pin ATX PSU to run this machine temporarily I need a safe way to reset the CPU rather than constantly power cycling. The RESET line comes from an ICL7611 op-amp via an MC14081B through pins 1-4 of a 74LS04 and I need to pull it low for longer than 3 clock cycles. I wish I had a schematic to show! Cheers, -- Adrian/Witchy Binary Dinosaurs creator/curator Www.binarydinosaurs.co.uk - the UK's biggest private home computer collection?

7 years, 4 months

LINCtape/DECtape Head Alignment

by michael.99.thompson＠gmail.com

> > Date: Sat, 18 Mar 2017 21:46:21 -0500 > From: Jay Jaeger <cube1 at charter.net> > Subject: Re: LINCtape/DECtape Head Alignment > > Curious: How are you measuring the signal from the head? Do you have > an honest to gosh differential probe, or are you using some other > technique? (If you have a differential probe, then the TU56 manual > indicates that you should see 10mv-12mv (the addition of the two paired > heads together), so as a first guess I am guessing you are looking at > the coils one at a time. > > The reason I ask is that the TU56 that I use most often has gotten a bit > cranky over the years. Generally I can read and write, but I do > typically see some errors - unacceptably many, and it *seems* that the > longer the machine is on, it seems the more mark track errors I get when > running the ZTCC?? diagnostic (test 3). > > I don't have a differential probe, and the A-B math function on my Rigol > DS2072 scope is not anywhere near fast enough (though maybe a firmware > patch which I have downloaded will help, but I doubt it will help > because their is a lot of HF noise on the signals when measuring > voltages this low). However, if I apply a 50KHz low pass filter on the > signal on the scope, then sometimes I can see a 5mv per coil signal > using an ordinary probe. I say sometimes because the scope seems to > have some firmware problems so it isn't consistent in its behavior. (I > have downloaded a firmware update that *might* help). > > I don't really doubt my heads at this point - certainly nothing is open > - I can measure each coil at about 1.5 ohms (3.0 ohms across both), but > it is something I would like to make sure I know how to do. > > Also, have you degaussed your heads? If so, how? I ask because some of > my symptoms could point that way (I have yet, for example, to test with > a tape, have it get worse, then go back with the machine "cold" and see > if it gets better - and if it doesn't, that could point to demagnetized > heads.) > > Thanks. > > JRJ > We used the procedure in the TU56 maintenance manual, and used two G888 modules to make the equivalent of the G500 described in the manual. The G888 modules really cleanup the high frequency noise mixed with the head signals. -- Michael Thompson

7 years, 4 months

Extracting data from DEC VAX tape recordings

by will.pearse＠usu.edu

Hello, I'm sorry to bother you, but I was hoping you might be able to help me with a problem I'm having getting hold of some scientific data that's currently stored on DEC VAX magnetic tape. A colleague of mine carried out some ecological fieldwork ~30 years ago, and her results are stored on eight magnetic tapes (two of 7" diameter, one 8.5", and five 10.25"). The data would be incredibly useful to look at, as the study was looking at how restored mines changes over time (the study is somewhat described here; https://www.jstor.org/stable/20038221?seq=1#page_scan_tab_contents). If we could get these original data, we could compare how the mine is now with how it was then, which would be phenomenally useful to conservation biologists trying to conserve and restore damaged ecosystems. Do any of you have any ideas as to how I might get the data off this tape? I live and work in Utah (USA), but I would be willing to travel a little ways if it meant getting the things read off into a computer! Thanks again for your time, Will Pearse --- Need a phylogeny? Try phyloGenerator: original<http://willpearse.github.io/phyloGenerator/> or new version<http://willpearse.github.io/phyloGenerator2/> Measuring phylogenetic structure? Try install.packages('pez') Will Pearse<http://www.willpearse.com/> Assistant Professor of Biology, Utah State University Office: +1-435-797-0831 Skype: will.pearse

7 years, 4 months

CF cards as storage - wear leveling

by jules.richardson99＠gmail.com

I just bought an IDE-CF adapter the other day with the intention of replacing the spinning rust in my disk imaging system (which is some early/mid-90s 80486-based thing). However, the CF entry on Wikipedia says: "Most CompactFlash flash-memory devices limit wear on blocks by varying the physical location to which a block is written. When using CompactFlash in ATA mode to take the place of the hard disk drive, wear leveling becomes critical because low-numbered blocks contain tables whose contents change frequently. Current CompactFlash cards spread the wear-leveling across the entire drive. The more advanced CompactFlash cards will move data that rarely changes to ensure all blocks wear evenly." ... I'm a little wary about the way it says "most CF cards", implying that there are some out there which don't do any wear-leveling at all. So, the obvious question: is there a way of knowing which cards are going to be good and which are useless as IDE replacements? Maybe by age, capacity, manufacturer? I'd prefer not to invest time into setting software up only to find that the card fails in a matter of weeks. cheers Jules

7 years, 4 months

LINCtape/DECtape Head Alignment

by michael.99.thompson＠gmail.com

The RICM is working on the skew adjustment on a TU56 tape drive on a PDP-12. We only see a 5mV signal from the head, so when we flip the tape over we will only see 1mV. This is below the capabilities of my 'scope. The DEC skew adjustment procedure talks about using a DEC amplifier to boost the head signal to several volts. We are planning to make an equivalent amplifier using a modern Op-amp. It would be really convenient to have one of the Amphenol 133-022-03 connectors from a G851 Relay module on our amplifier so it would plug directly into the head cable. Does anyone have a DEC G851 module that we could remove the connector from? -- Michael Thompson

7 years, 4 months

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test-drb March 2017