test-drb May 2010

test-drb@ccmp.vtda.org

189 participants
248 discussions

by cclist＠sydex.com

Folks, Awhile back, I posted a message from someone with a few Intel MCS-8 cards available. He still hasn't received any tickles on them. They can't be all that common. Email me if you'd like and I'll pass the message along. AFAIK, the cards are in the USA. --Chuck

14 years, 1 month

Semi-OT - Using optoisolators with composite video signals

by ian_primus＠yahoo.com

I have the need to optically isolate a composite video signal to compensate for the different ground reference between the devices. Digging through my stash of parts, I have some optos, but the ones I have are more suited to digital applications. Having not tried to pass an analog signal through one before, I'm not quite sure what sort of part I'm looking for... Anyone have any suggestions? -Ian

14 years, 1 month

cctalk Digest, Vol 81, Issue 46

by mtapley＠swri.edu

At 3:41 -0500 5/18/10, Jeff wrote: >See, having me in your Spacecraft Design class all those years ago is >coming in useful after all. Count the caps and the markings, and email >me. I've got the replacements. Knew it at the time, never doubted it since. Thanks one and all - I'll contact Jeff for parts and more advice if I can't figure out the removal/replacement process. I *really* like being on this list - the on-list and off-list replies have been very gratifying! -- - Mark 210-379-4635 ----------------------------------------------------------------------- Large Asteroids headed toward planets inhabited by beings that don't have technology adequate to stop them: Think of it as Evolution in Fast-Forward.

14 years, 1 month

questionably OT: AmigaOS 4 on Mac PPC

by spectre＠floodgap.com

I see notes around the underweb about people using a custom OpenFirmware loader to get AmigaOS 4 booting on the G4-based Mac mini. This sounds like a ready-made way to create an Amiga laptop -- just use an iBook G4, which is nearly identical technically. Has anyone tried using the Moana loader? I am intrigued by AmigaOS, but I don't really have the space to set up a new PPC Amiga to try it (thus a laptop form factor would be fabulous). -- ------------------------------------ personal: http://www.cameronkaiser.com/ -- Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com -- I think, therefore I'm dangerous. ------------------------------------------

14 years, 1 month

PDP8/A for sale

by 1metalguru＠gmail.com

To those interested in my PDP8/A system: It contains: 1 - M8315 Hex Omnibus CPU 1 - H219B 16K Core Memory Module 1 - M8316 Option Board 1 with 1 - KC8AA Programming Panel 1 - M8317 Option Board 2 bootstrap 1 - M8342 Parallel Control 1 - M8357 RX8E Omnibus Interface 1 - M8326 Inter-processor Buffer 1 - PDP8/A Field Maintenance Print Set. 1 - PDP8 Internal Bus Options Maintenance Manual Vol 2 I am accepting offers to purchase this unit. I live in Calgary, Alberta, Canada. I have checked with UPS and Xpress Post and shipping to the continental United States would start at approximately $100, assuming a package 24x24x12 weighing 60 lbs. I also have a PDP8/I WO25 Core Memory Module mod 30-05256-2 made by Data-Ram Corp.: Darrell

14 years, 1 month

video opto isolator single chip solution

by rdawson16＠hotmail.com

Ian, Here you go 8 pin DIP, and app note circuit in the datasheet: http://www.avagotech.com/pages/en/optocouplers_plastic/plastic_wideband_ana… Randyc _________________________________________________________________ The New Busy is not the too busy. Combine all your e-mail accounts with Hotmail. http://www.windowslive.com/campaign/thenewbusy?tile=multiaccount&ocid=PID28…

14 years, 1 month

cctalk Digest, Vol 81, Issue 43

by ken＠seefried.com

On 5/17/2010 12:49 PM, Sridhar Ayengar<ploopster at gmail.com> wrote: > > Tandy wasn't the only other company making MCA machines. NCR made quite > a few different models. I believe Siemens made one or two as well. > The NCR Microchannel machines were quite well done. They spanned i486 and Pentium 1 desktop machines (the 3000 series?) through the WorldMark series with up 16 (or was it 32?) PPros running SVR4 to the Terradata-based boxes like the 3600 & 3700. I did some pretty interesting stuff on the later two at a large airline a long time ago. There was some definite teething pains with the SMP implimentation, but those were impressive boxes when things went well. Olivetti made some interesting Microchannel machines as well. KJ

14 years, 1 month

Anyone off to VCF-UK?

by ken＠seefried.com

On 5/17/2010 12:49 PM, "RodSmallwood"<rodsmallwood at btconnect.com> wrote: > > It seems to be a bit like the aircraft preservation people. One of > everything but nothing flies. I just hate that. If something was built to > run and can run again with out damage it should. > To be fair, when a classic computer fails in use, it's pretty uncommon for anyone to die, and somewhat less uncommon for the entire device to be destroyed in the process. Exactly the opposite is true in the case of an aircraft. I can assure you that flyers want to fly, especially something interesting and/or unique, but sometimes the risk assessment doesn't make that smart. KJ

14 years, 1 month

Mac Classic problems

by trag＠io.com

> > Date: Mon, 17 May 2010 11:02:56 -0500 > From: Mark Tapley <mtapley at swri.edu> > First pass, no sound out. Not speaker, not headphone > connector. Wait, if you hold your ear right up against it, you hear a > *little* bit. Hm. This is a (uhm) classic symptom of leaking caps on the Classic, and Classic II, and SE/30, and IIci, etc. We regularly discuss this issue (these days we usually just reference old threads) over on 68kmla.net. A search on "tantalum" is probably best, as the typical replacements we use are tantalums of the proper size and values. > gunge, and they were centered on the three groups of what look like > my favorite nemesis .... capacitors! > > <gnashing of teeth> > > Many q-tips and much isopropanol later, it boots, but it's > still quiet - too quiet - and I have a bad feeling about how long > it'll keep running before I have to clean it again. There's a bit of > corrosion on one lead of the sound chip, but I can still hear a very > very faint edition of the sound it's supposed to make. > > 2) If (sigh. When) I have to pull those things off, I will need a > hot-air soldering station, correct? My thought is, cut up an aluminum > can to make an air dam isolating the cap. from the rest of the board, > then blast it with hot air until it flies off or vaporizes. Is that > close to right? Use two pencils simultaneously. Radio Shack sells a 15 watt grounded pencil with a fine tip for less than $10. If you use two pencils you're much less likely to lift a pad by prying on a cap while heating one side, and after the other side has already cooled. If you were to use hot air, I find that modeling clay works conveniently and well to protect other components on the board. The simple procedure is: 1) Remove the old caps and remove the solder on the pads. 2) Clean the board thoroughly. 3) Replace the capacitors. To replace the caps, tin one pad. Place the cap carefully and hold it down with something like a small flat screwdriver. Heat the tinned pad until the caps sinks down to the pad. Remove the heat. Wait a few moments. Remove the pressing tool. Now solder the other pad/terminal. > 3) How do I get replacements, and how do I slap those back down on > the board? Is the code on the top all I need to order more? See, having me in your Spacecraft Design class all those years ago is coming in useful after all. Count the caps and the markings, and email me. I've got the replacements. Jeff Walther

14 years, 1 month

RD53 Restoration

by ard＠p850ug1.demon.co.uk

> > Yes "blipping" the coil with a 9V battery moves the heads. When the drive > was powered on I also measured the voltage by attaching a probe to each end > of the coil cable, in that case I measured about 1.3V only. So I am guessing > the coil is OK. Next step is to swap the boards back again. And then fix the real fault :-) More seriously, it sounds like the positioner coil is not being driven hard enoguh to move the heads -- and if the coil was open-circuit I would ecpect the servo sysem to try to drive it very hard to attempt to get some movement. Normally there are various conditions which have to be satified (motor up to speed, no write current unless write gate is asserted, only one head selected, etc) before the heads will move. It's entirely possible the problem is in one of those areas. -tony

14 years, 1 month

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test-drb May 2010