test-drb June 2002

test-drb@ccmp.vtda.org

205 participants
502 discussions

by Robert_Feldman＠jdedwards.com

http://www.allelectronics.com/matrix/7_Segment_Displays.html 0.3" character height, red or green. -----Original Message----- From: Jim Kearney [mailto:jim@jkearney.com] Sent: Monday, June 03, 2002 1:09 PM To: cctalk(a)classiccmp.org Subject: Re: [OT] Need 7 segment displays... >From: "Gene Buckle" <geneb(a)deltasoft.com> > I'm trying to find some VERY small 7 segment displays. I need a part > that's small enough that 5 digits will fit into an inch long area. I'm > not having any luck and I'm hoping someone here might know where I can > find them. I don't know where to find them, but LED calculators in the 70's sometimes used 4 digit modules with a DIP-16 form factor. They looked like 4 bubbles on top of a lead frame. That would make them about 3/4" for four; but I'm not sure how you'd get 5 unless you could also find a 'single'. Not very helpful, I know, but perhaps a step in the right direction...

22 years, 1 month

what the heck is this? Apple II Adaptive Firmware Card

by rigdonj＠cfl.rr.com

Hi, I recently picked up a card and external box for the Apple II. Both say Don Johnson Development Equipment Inc Adaptive Firmware Card and the box also says I/O Box. The box connects to the card via two short ribbon cables and has a 36 pin male Centronics style connector, two banana jack sockets, rocker switch and a LED on it. I picked this up in Topeka, does anyone know what it is? Joe

22 years, 1 month

locating shorts Re: HP ScanJet ADF

by dwightk.elvey＠amd.com

>From: Joe <rigdonj(a)cfl.rr.com> > > >>Probably a shorted decoupling capacitor (if it's a 'dead short' or close >>to one). I have been known to carefully cut power traces to find out >>which section is shorted, and then home in on the problem. > > That's the way that I've traced shorts down. However since then I've bought a HP Current probe, they're supposed to be able to trace a short down the correct path. I've never had a need for it since I bought it so I dont know how well it works. Has anyone had any experience using one? Hi I've used a current probe a number of years ago and found it worked OK for trace short, when they were accessable on the surface. I've since found a method that works fine for me, using standard bench top items. You need a 4 or 5 voltmeter that has at least a 200 uV range and a current limiting power supply. What you do is to place about a 1 amp current from end to end of the curcuit that is shorted to another curcuit. Do not place the 1 amp through the short. This will generally create a 20-100 uV drop across the curcuit. Now, clip one lead of the meter on the other curcuit ( the one that this curcuit is shorted to ). With the remaining lead, trace along the curcuit with the current flowing through it. When you get to the point where the short is, the voltage will be zero. On either side, the voltage will be plus or minus, telling you which way to go. Check the meter regularly for offset by connecting both meter leads together. This will help you especially when you get close. For curcuits with branches, you may need to move where you put your end to end current to follow another branch. This method also works for power planes. Say there is a bypass cap that is shorted someplace. Place the current source on opposite corners of the board and trace until you have a line ( usually curved ) across the board that measure zero ( I usually tape a piece of string along this line ). Move the current source to the other corners. Again, find the line. Where the lines cross, you'll find the short. There are variations of this method that I've used to find multiple shorts. Dwight

22 years, 1 month

sorce of computer recyclers

by DAW＠yalepress3.unipress.yale.edu

> From: Gary Hildebrand > > I just came acrtoss this ---- there might be some good sources in here > for goodies. My gold mine in Topeka is part of this list, so I'm > betting on at least a couple more . . . . . > > > http://www.recycle.net/computer/used/index.html > > Seems like a decent resource... Did you happen to notice the Titan Trailers ad/link at the bottm of the page? ;) -- --- David A Woyciesjes --- C & IS Support Specialist --- Yale University Press --- (203) 432-0953 --- ICQ # - 905818 Mac OS X 10.1 - Darwin Kernel Version 5 Running since 01/22/2002 without a crash

22 years, 1 month

Airport screening (was Re: KC/Topeka prowling with Mr. Rigdon)

by acme_ent＠bellsouth.net

> From: Sellam Ismail <foo(a)siconic.com> > Whoever tells you the checks are "random" and not based on ethnicity or > appearance is just trying to be PC. I'm sure there is a bit of randomness > involved, but that's for the non-Arab, non-Muslim flying contingent. > There's only been one time out of perhaps ten where I didn't have to go > through the extra pre-boarding check before a flight. No offense, Sellam, but this only seems natural to me. I'm sure the airport security checks have gotten a bit tiresome, but we recently were attacked by Arab Muslims, and several thousand people died. If we'd been attacked by Irishmen I'm sure we'd be taking a harder look at them, too. Glen 0/0

22 years, 1 month

drive "hood" parts[was: RE: DEC SDI drives]

by xds_sigma7＠hotmail.com

Come to think of it, the gas shocks do somewhat remind me of the ones on the rear gate of my subaru station wagon... or on the hood of a BMW... hmm... Will J _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp.

22 years, 1 month

sorce of computer recyclers

by ghldbrd＠ccp.com

I just came acrtoss this ---- there might be some good sources in here for goodies. My gold mine in Topeka is part of this list, so I'm betting on at least a couple more . . . . . http://www.recycle.net/computer/used/index.html Gary Hildebrand St. Joseph, MO

22 years, 1 month

drive "hood" parts[was: RE: DEC SDI drives]

by DAW＠yalepress3.unipress.yale.edu

> From: Andreas Freiherr > > Gunther Schadow wrote: > > > > ... Then you can open the hood just like > > in my car, check the alternator belt and I just haven't found the > > oil dip stick yet :-). > > My trouble with it is that the "hood" always bounces back on the rear > part of my head, because the pressurized gas retainers have lost their > magic smoke in the cause of the years. I am convinced it's impossible > and perhaps even dangerous to repair (i.e., to repressurize) them, but > is there a known good source for spare parts? > > Without looking: are these parts the same type in a RA80 and in a RA82? > > I don't want headaches every time I adjust belt tension... > > -- > (continuing the automobile analogy...) How big are the gas shocks? Anything like the ones that hold up a hatchback in car? Auto part places like JCWhitney.com sell replacements... -- --- David A Woyciesjes --- C & IS Support Specialist --- Yale University Press --- (203) 432-0953 --- ICQ # - 905818 Mac OS X 10.1 - Darwin Kernel Version 5 Running since 01/22/2002 without a crash

22 years, 1 month

Diagnosing a non-working Mac Performa 476?

by vaxzilla＠jarai.org

I've acquired a non-working Mac Performa 476. Unfortunately, I don't have any other Mac gear to help me with the diagnosis. I've the Performa 476 itself, which may or may not be working; I've got two Macintosh Color Displays (M1212) which may or may not be working, and one spare Performa 475 motherboard purchased from eBay. It was advertised as pulled from a working system--but I've no way to verify this. The seller was a reputable one, so I'm inclined to believe it's a good board. The 475 motherboard is identical to that of the 475. The difference between the two models being that the 476 shipped with a larger internal HD. When I power up the system, with monitor attached, the internal cooling fan spins up, the hard drive spins up (and sounds normal), and the machine chimes what I seem to recall as being the regular start up sound for this era of Mac. However, the display remains dark. If I power off the Mac, leaving the monitor on, the monitor makes a light static/crackle noise; it's the sort of sound I normally associate with a monitor that's lost the video input signal. I've played with the brightness and contrast controls without any success. If I switch the other monitor, the behavior is the same. If I switch >from the orginal motherboard to the one I purchased on eBay, the behavior is the same. It's possible both monitors are bad and/or both motherboards are bad. I don't have a multimeter to verify that the voltages coming out of the PS are correct. Nor do I know that the hard drive is functional--but I'd assume that nothing needs to be loaded from the HD in order to get the display to come up. I'm a bit puzzled, and wondering if anyone here with insight on these Macs and their displays can give me any additional pointers. -brian.

22 years, 1 month

Osborne 1 Video Adapter? (was:RE: IBM 026 Printing Card Punch )

by Robert_Feldman＠jdedwards.com

AFIK, OCC never sold a composite adaptor themselves. The one I had was a Monadapt by JMM (?). I also have a copy of the Osborne 1 Technical Manual (Thom Hogan and Mike Iannamico, copyright 1982). It describes the video circuit, with schematics for the edge connector and brightness/comtrast pots, but it does not have a schematic for a composite adaptor. Bob -----Original Message----- From: Joe [mailto:rigdonj@cfl.rr.com] Sent: Saturday, June 01, 2002 7:15 AM To: cctalk(a)classiccmp.org; acme_ent(a)bellsouth.net Subject: Re: Osborne 1 Video Adapter? (was:RE: IBM 026 Printing Card Punch) Glen, Didn't I give you the Ozzy Technical manual? I think they describe their version in there and I think they even include a schematic. IIRC there's nothing in it except for two connectors and a transistor. I believe it replaces the "Do Not Remove" plug on the front of the Ozzy. Joe At 01:02 AM 5/30/02 -0400, you wrote: >> From: Feldman, Robert <Robert_Feldman(a)jdedwards.com> > >> I was looking through the Alltronics listings and noticed a TTL-Composite >> video adaptor (http://www.alltronics.com/computer_miscellaneous.htm , >> #92C024) that looks like the adaptor I have for my Osborne 1! > >Robert -- > >Please tell me more about this adapter. I like my Oz 1 but hate the >screen. Where does it connect to the Oz? > >Glen >0/0 > >

22 years, 1 month

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test-drb June 2002