test-drb December 2005

test-drb@ccmp.vtda.org

235 participants
580 discussions

by jcwren＠jcwren.com

I've got a system with a couple large electrolytics that hasn't been powered up in a number of years. I have a 5A Variac. What's the typical procedure for the reformation process? Remove all cards (or maybe leave a junk card in for load?), start the Variac at 0V, increment by 10V every so often? How long per step, and/or is a different step suggested? I've seen lots of people say "you'll need to reform the caps, first", but never a prodecure for it. --jc

20 years

Hp plotter

by brushman＠esper.com

Tony, thanks for the help. It's more than I knew before. I can be persistent, in fact a friend of mine is looking up "communications analiser" as we speak. He too uses an old HP. Somewhere, I may find the answers. I've got friends that are very much into computers. The more I think about it, the longer the list grows! One for instance had me paint "free recycling" on the front of his computer store. That sounds like something with real possibilities for the people on this board. He gets shipping pallets full of the old stuff. Got to be something interesting in there. How about this: you just go to a sign maker, have them cut you some vinyl letters that say "free computer recycling, www..." maybe a ph number. Put the lettering on the back window of you vehicle, and bingo! Old stuff. Find out what they have, if you're not interested, give the location of a different place that takes it. In fact, to show my gratitude for this board, I'll send said lettering FREE to the first 3 people that ask for it. :) Just havin' fun (but the offer is valid), thanks again.

20 years

Legacy apps in Windows/OS X was Re: Old MS-DOS & Win Software

by ajp166＠bellatlantic.net

> >Subject: Re: Legacy apps in Windows/OS X was Re: Old MS-DOS & Win Software > From: Jim Leonard <trixter at oldskool.org> > Date: Wed, 07 Dec 2005 17:22:52 -0600 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Cameron Kaiser wrote: >>>What's really water under the bridge is 16-bit mode in Windows. Vista >>>doesn't support it, period. Maybe someone will write a 16-bit emulator > > >> PPC applications written for the G3 under Carbon. That means Classic apps >> -- including 68K apps -- will probably die in the future. > >What bothers me is: How hard is it to include an emulator? Who cares if the >emulator is 100x as slow as the real thing when you're running it on a machine >that is capable of running OS X or Windows Vista? >-- Jim, It's real hard when the vendor(s) want you to buy office suite 2007 or whatever. Till someone (not a vendor) gets the emulator written the rest of will run it on classic hardware and software. "The only way to win the game is to not play." Allison

20 years

Cap reformation question

by dwight.elvey＠amd.com

Hi I found the government reference. It is at: http://www.multi-volti.com/hb1131.pdf They mention using a lamp as a current limiter but as I stated earlier, lamps have changes in resistance with temperature. Unless the lamp is used in the intended voltage range, one can not depend on the resistance being close. They recommend reforming when stored for more than 3 years. They state that if the capacitor does not reform in 3 hours, it is considered bad. The values they show are for larger filter capacitors ( my guess as this is an old document ). They show 5 ma for axial and 10 ma for screw threaded radials. It should also be noted that they are not trying to save every capacitor, just put capacitors into condition for use. If one shorts, so be it. If you are trying to save capacitors, you might want to be a little more friendly to it. Dwight >From: "Dwight K. Elvey" <dwight.elvey at amd.com> > >Hi > There is a government spec on reforming >capacitors that have been in storage for >military specs. I don't recall if I saw this >on this list or maybe one of the news groups. >Dwight > >

20 years

Opening a classic Mac

by compoobah＠valleyimplants.com

Pretty easy- long handled T-15 to remove the two screws under the handle and two at the lower back. I wouldn't use the screwdriver-you can scar the case and it's usually not necessary. Put the Mac facedown on a soft surface, lift it a little by the back and shake- that has always done it for me. Another thing that can work is one of the "stationary clips" with the round spring (not the ones with the blued spring steel shaped a bit like a triangular prism). Once you have the cover off, worm your fingers in and disconnect the power, SCSI, floppy et al before pulling out the board. The SE&SE/30 expansion cards are two piece, you should be able to disconnect the cable and remove before pulling the mainboard.

20 years

Building M8027 hookup

by ajp166＠bellatlantic.net

> >Subject: Re: Building M8027 hookup > From: Dennis Boone <drb at msu.edu> > Date: Wed, 07 Dec 2005 14:45:34 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > > > I've looked at that manual before posting, and it does not have much > > to work out from. All the names of the signals are different. > >Ready is inverted between the two, I think. Both have the same basic >data transfer signals. Dataproducts has forms handling stuff that's >not in centronics. the LPV-11 was a upgrade and improved LAV-11. The LPV-11 has jumpers to handle things like parity, polarity of strobe to mention a few. All the manuals I have show the jumpers but do not give pinouts.. >You should be able to compare what's in the LPV11 manual to these and >work out which are which. Then figure out the pin numbering schemes >used in the LPV11 manual. They use an identical connector. TO sort out how to make a foreign cable you really need the printset for it. Either that or wire a DLV-11 serial card and use that to drive a serial interface printer. Allison

20 years

Building M8027 hookup

by ISC277＠CLCILLINOIS.EDU

OK, I'm trying to build myself a hookup for an M8027(LPV11) to run to my distribution panel. I've done some reading, and it is clear that this is a Centronics compatible card, so I have the right one. Does anyone know the pinout for this device? I'm confused. I know you can use other printers with this card, and I'm just looking to do raw text to an old Panasonic dot matrix printer - but I don't know what signal is what. As usual, any help is appreciated. TIA Julian

20 years

HP86B/HP85 PSU testing - where to start?

by vp＠cs.drexel.edu

Regarding www.series80.org: Lyle Bickley <lbickley at bickleywest.com> wrote: > Forget my last comment re:login/passoword - I was using the Konquerer browser > - when I changed to the Firefox browser - all was O.K. (you do need a > login/password - but you are given them in Firefox's error message). Sorry about the authentication step, but it has slashed downloads >from automated tools from my site. I find that this works much better than robots.txt because few (if any) robots are clever enough to look at the error page for the passwd. BTW the incantation is also present in the authentication window (but I guess nobody ever reads messages on pop-up windows anymore :-) **vp

20 years

Cap reformation question

by dwight.elvey＠amd.com

Hi It is an interesting article but I suggest that the leakage currents may be over stated. 1,000 ma at 500 Volts is 500 Watts. This is way too much for a capacitor. Even 1 ma at 500 volts is quite a bit more than most capacitors can handle for any length of time at 500 Volts. I would suggest that the translation from the original article may have replaces the micro symbol with a m instead of a u as is normally done. Things to consider are that there are two factors when reforming. There is the production of gases that is directly related to the current flow and then there is the power dissipated. This is voltage times current. Both must be considered. A 500 volt capacitor should never have more than 1 ma of current flow and should most likely be in the 100 ua range for much of the reforming. Low voltage capacitors can handle more power but become limited by the gases produced and not the power. 10 ma for a good sized can is about max. Smaller cans should have less current. A small 10 uF 30V cap shouldn't have more than 25 to 50 ua at most. It has been mentioned that one can use current limited supplies. I've not seen ay that would limit the current to a fine enough adjustment to be correct for reforming. A resistor is best. Always start with a lower voltage even if you have a resistor. The oxide coating in the capacitor is not evenly eroded. It has a number of locations that may be thinner. These need to be brought up to the level of the rest without over heating them locally. To determine when to bring the voltage up, watch the voltage drop across the limiting resistor. I recommend starting with a voltage of about 1/10 the rating and measuring the voltage. Each time the voltage is increased, never let the current go more than was seen at the beginning. This can be observed by watching the voltage drop on the resistor. Never start with more than 1/2 the rated voltage, regardless of the current limiting resistor. Always finish by bring the capacitor to the full operating voltage. One doesn't need to bring it to the rated value. Most of the methods mentioned here for current limiting protect the rest of the supply but not the capacitor. A lamp on the input leads will not do much to limit current at the levels needed to keep excess gas from building in the capacitor. Those that have had success have been luck rather than having a good procedure. Remember, excess gas will not show failure until some later date. The capacitor will seem to be OK but dry up over time because of a ruptured seal. Using a lamp on the input to a variac may not be too useful. The variac waste quite a bit of power. In order to get the variac to a useful operating level, the current limiting will be way beyond what is useful in protecting a capacitor while reforming. A series resistor at the capacitor is the only method I know that is truly safe for the capacitor! Dwight. >From: "woodelf" <bfranchuk at jetnet.ab.ca> > >Joe R. wrote: > >> Q: How high of a voltage do you use the reform the caps? I'm wondering >>if it's necessary to apply full (or nearly full) rated voltage or if >>they're fully reformed at say 5 VDC. Has anybody done any testing in this >>area? >> >> >I assume the vorking voltage + some safety margin. >A quick search found this link on the web of a circuit to reform the caps. >http://www.vmars.org.uk/capacitor_reforming.htm

20 years

really off-topic: used car parts for US car?

by bert＠brothom.nl

Hi, My apologies for being so off-topic, but I see this mailinglist as a nice place to find nice people that think alike. Here's my question: can anyone give me an address where I might find a used fuel pump for a hercules white car. The engine is a 6-cilinder. I think it's an rather uncommon car in the netherlands so that may explain why it is so hard to find parts for it. Thanks in advance and kind regards, Bert

20 years

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test-drb December 2005