test-drb February 2003

test-drb@ccmp.vtda.org

337 participants
780 discussions

by jrkeys＠concentric.net

Got a few new items at auction today: 1- hp 660LX no ac adapter and batteries are down so can not test it. 2-IBM PowerPC tower Risc6000 C10 not tested yet. 3-Sun Field Engineer Handbook Volume II pretty cool stuff in it. Covers these architectures: Sun-3, Sun-3x, Sun-386i, Sun-4, Sun-4c, Sun-4m. 4-hp 5314 A Universal Counter with manual. 5-hp 5381A 80mhz Frequency Counter with manual. 6-Fluke 1900 A Multi-Counter. 7-Datapulse model 201 Data Generator. 8-Sun UltraSCSI external with 9gig HD in it. 9-hp Apollo And some mousepads, Analog cards (4), and other goodies I have checked out yet.

21 years, 8 months

DEC VT 320 with Terminal Disease - help?

by mtapley＠swri.edu

All, yep, it's me again. The 4000 VLC started and ran perfectly. I left it on for about 8 hours as a burn-in test. When I came back, it was (apparently) still running - but the VT-320 it was talking through had died. Arrgggh. I've done a little investigating, so hopefully I won't need quite so many exchanges to get this one going. The external symptoms of the VT320 were: no display; when power switch is on, the LK201 lights flash about once a second. No other sign of life. I turned it off, unplugged it, and opened it up. The power supply board at the side has an output indicator LED which also flashes about once a second. I turned it off, unplugged the power supply board from the mainboard, and turned it on again. In this condition (which I'll call "unloaded"), the output indicator LED comes on and stays on. In addition, the pins on the output connector go to more or less their correct voltage, as determined by labels on the mainboard at the other end of that connector harness: Labelled Ground 5V 12V 18V Actual Ground 6.5V 12.5V 22V The power supply has a big (10-pin) transformer inside a cage (with some other components) on it. The transformer seems to divide the circuitry in two, inasmuch as only the "Ground" traces seem to go to both sides. On the input (upstream, plugs into wall) side, there is a network connected to a UC3842N IC. Google led me to a spec sheet for that, which calls it a "Current-mode PWM Controller". The spec sheet also has a "typical application" schematic for an "Off-line Flyback Regulator" which looks to be at least somewhat similar to the upstream side of the power supply, though I have not traced the latter out well enough to be sure yet. There are also several large electrolytic capacitors on the input side of the power supply. Possible signs of trouble are there, in the form of scorch marks on the PWB around two power resistors (? They have what looks like a powder blue ceramic exterior, are marked 120 Ohms +/- 5% and ?? (maybe 47 Ohms), and are much bigger than most of the resistors on the board). In the "loaded" condition, the resistor with the worst scorch marks around it (R523, as marked on the circuit board) has 0V across it, with a small spike upward (as shown by the needle jerking on my analog VOM) each time the output LED flashes. In the "unloaded" condition, my VOM shows 15V across that resistor, and it gets pretty warm pretty fast. Questions for the group: 1) Have I got good evidence that the fault this time is actually on the power supply board, and not a pull-down on the mainboard, as it was on the VAX 4000 VLC? 2) Is there a good way (without use of an ESR meter, which I haven't got) to isolate which component is bad, or should I just replace the capacitors on suspicion? The power supply, at least, looks very easy to work on. Nice big components, circuit board is only 2 layers (front and back) and not very many traces on the component side, and the traces are exposed and easy to get to in its operating configuration. I'm being careful around the 120VAC (rectified to 160 DC in the unloaded condition). Thanks in advance for any help you can give me! - Mark

21 years, 8 months

Check out this TI99/4 on eBay

by alhartman＠yahoo.com

> From: "TeoZ" <teoz(a)neo.rr.com> > > My first computer was a timex 2068 and learning to > program on chicklet keyboards sucks. But.. Those were pretty nice computers... Timex did make an incredible goof with those... Originally, it was intended to be an American Version of the 48k ZX-Spectrum Computer. But, as-is it wouldn't pass FCC regulations. So, they redesigned the computer to do so, and decided to "improve" it. Designing out most compatibility with the Spectrum in the process. With a set of Spectrum ROMS in a cartridge, and a "Twister" card (to convert the expansion edge back to the Spectrum version), one could use Spectrum Hardware and software on it. There were third party keyboards for it also, and when Sinclair was bought out, the company that bought it (I can't remember the name), made better versions of the Spectrum with built in Microdrives or Cassette Player, and a better keyboard. I have a U.S. Prototype of the Spectrum, a Microdrive interface and drive, and the Timex of Portugal 3inch Disk Drive System (which also turned it into a CP/M Computer). A nice computer for the time if you tricked it out a little. The company I worked for in the 80's even made a drawing program similar to MacPaint for it, called TechDraw, A Spectrum Emulator Cartridge, Disk System, Terminal Software (for the Timex Modem), and lots more... Also, fun days... I hope to spot one at a flea market to have one again. I still have my ZX-81 though. You can still get kits for the ZX-81, and some books and software from www.zebrasystems.com Regards, Al Hartman

21 years, 8 months

M9312 Bootstrap Questions

by jss＠subatomix.com

Ok, I got my PDP-11/34 mounted in its rack and have started to audit jumpers, switches, etc. I am being cornfused by the M9312 bootstrap terminator module. First, I'm confused about what version of the module I have. My 11/34 user's manual (EK-11034-UG-001 '77) talks about a -YA, -YB, and -YF version of the board. My M9312 manual (EK-M9312-TM-003 '81) talks only in terms of bootstrap ROM part numbers. The DIP switch references in the two documents conflict, even differing on the switch settings necessary just to boot into the console emulator. My M9312 has no -Yx designator and has only one bootstrap ROM installed (756A9 for RK03/05/05J or TU55/56). The M9312 manual seems to make the most sense in this case, so I've been believing its side of the story. However, the DIP switch settings on my M9312 have me puzzled. Here they are: 1 2 3 4 5 6 7 8 9 10 ON ON ON OFF OFF OFF OFF OFF ON ON This doesn't correspond to anything in either manual! According to the manual I'm trusting, this says to start executing at 765406 (in the console emulator ROM). It needs to be 765020 (with diags) or 765144 (without diags). Supposedly, the machine was functional when it was decommed, so my first instinct is to assume I am (or the docs are) wrong somewhere. However, its previous owner (another collector) was not able **IIRC** to get a register printout at power-up. So maybe the DIP switch is pointing to someplace that isn't a valid entry point. I don't have access to the complete M9312 print set, which would list the ROM contents. Should I reset the DIP switch to say 765020? -- Jeffrey Sharp

21 years, 8 months

Multilingual programming (was Re: Litton Industries Monrobot XI computers available)

by dwightk.elvey＠amd.com

>From: blstuart(a)bellsouth.net > >In message <3E5D4EA2.5080309(a)aconit.org>, Hans B Pufal writes: >>Unlike BASIC, PAF was designed so that its >>key words could be easily changed to different languages and on the fly >>during one progam, a feature I have not seen in any other language. I thought I'd mentioned that it is not entirely true that no other computer language can be converted to another language. Not being a natural language, Forth, can easily be converted to any standard text type language and there has even been efforts to convert to Chinese( not text type ). Since Forth has its own rules on noun/verb/object order, the language that it uses is not important. This is unlike most languages because most use complex precedence rules( LISP being another exception ). One can not fully overload the + operation in languages like 'C' because it would end up looking like +( a, b ) instead of a + b. I know of at least one German Forth and work in progress on a Chinese Forth ( issues are mainly entering and displaying characters ). Both of these can be source files loaded >from an English ( or other language ) Forth to completely change the Forth. One can even have both at the same time and switch back and forth. Heck, One might even have three languages or more to select from. One's imagination is the limit( and real memory). Dwight > >At the 1981 National Computer Conference (US), Grace Hopper told >a story about the A0 compiler she and her collegues did on the >UNIVAC. Part of the motivation for this program was to settle >the question of whether a computer could write a program for >itself. So the thing we now understand to be a programming >language was made as close to a natural language as they were >able to do at the time. Every statement consisted of a subject >a verb and an object followed by a period. (You can probably >begin to see how this work influenced the development of COBOL.) >Anyway, to demonstrate the flexibility of this technique, they >had both English and German versions. However, since it was a >US military sponsored project and since it was rather soon after >WWII, the German version caused a minor freak-out on the part of >some of the military brass. It was quickly shoved in a corner >and was lost in the mists of time. > >Brian L. Stuart

21 years, 8 months

Datapoint MiniComputer

by dstalnaker＠mindspring.com

Hi, I am looking for a Datapoint Mini computer from around the 1980-1983 timeframe. Any chance you have one or know of anyone else I might try? Thanks, Debbie

21 years, 8 months

Two (NEW) LA36 Decawritter II's for sale

by edgosch＠advanced-energy-conv.com

If anyone is interested. I have two brand new LA36 Decawritter II's for sale. I personally took these off their shipping pallets sometime in the late 70's or early 80's. They look absolutely new. Original test printout and manuals are still with them. They have been stored covered all this time. Ed Albany, NY w2uv(a)arrl.net

21 years, 8 months

ISIS-II command summary?

by melamy＠earthlink.net

Hi all, I got my Intel MDS225 working today, but I only have a single double density drive on it. I seem to recall that it would read single density, but you accessed by a different drive specifier. I can't seem to find one bit of documentation on the ISIS command at home. Does anyone have a summary page they could scan and send? I am also looking for the 50 pin connection wiring so I can connect a drive externally. It was fun booting up ISIS-II version 4.2 and seeing the prompt come up. I also had a CP/M 2.2 version that booted perfectly! best regards, Steve Thatcher

21 years, 8 months

TRS-80 Model 4 help requested

by rigdonj＠cfl.rr.com

Hi pat, I too just picked up a model 4. I didn't get any disks but mine says "Disk?" when I power it up. I opened it up and mine is a basic 64k machine with two SS disk drives. The drives in mine are made by Texas (somebody), Texas Peripherals maybe? I checked and they're 40 track SS drives. I believe these are the original disk drives for the M4 but I've been told that they will support 80 track and DS drives. But I don't know if you had to patch the BIOS and/or OS to do that. Joe At 10:38 PM 2/25/03 -0500, you wrote: >I recently picked up a TRS-80 model 4, that seems to have problems with >its floppy drives. > >The machine is a base Model 4 with 64KB of ram (I think - haven't yet >taken the EMF shield off the mainboard), and no peripherals attached. >When I powered it up the first time, with or without a disk in the >(bottom) drive, it displayed "Cass?" on the screen, and then I could press >enter to that and the "Memory size?" prompt, and get a basic prompt. > >I tried swapping the floppy drives, and that time I got a "Diskette?" >prompt if there was no disk in the drive, and pressing any keys didn't >cause anything to happen. If I put a disk in the drive, the machine never >displays anything, and then after 10-20 seconds, the drive light goes out. > >I tried connecting only one drive at a time, with the same results. If I >connected a 1.2MB floppy that I had laying around (a Teac FD-55GFR-149-U), >it did the same thing as if the drives were swapped. Yes, I realize that >the drive probaly wasn't going to work, I just wanted to see if it did >anything. > >Also, the disk I used was supposed to be a TRS-DOS (bootable) disk, but >it's possible that they've gone bad after so many years. Are the disks on >the Model 4 recorded so that I can read them on a PC (IE 48/96tpi MFM, >compatible with the NEC D765)? I'd like to know if I can make backup >images and/or see if the disks work on another machine. > >Thanks. > >Pat >-- >Purdue Universtiy ITAP/RCS >Information Technology at Purdue >Research Computing and Storage >http://www-rcd.cc.purdue.edu

21 years, 8 months

Cost of shipping a container

by Innfogra＠aol.com

In a message dated 2/26/03 3:20:39 PM Pacific Standard Time, vcf(a)siconic.com writes: > > I said it's US$3,000 for a 40 footer. It's actually US$3,000 for a 20 > footer from the west coast of the US to Europe. It was about $5000 to ship a 40 foot container of scrap from the Pacific NW (Tacoma was the cheapest IIRC) to Taiwan or Indonesia when we were doing that in the mid 90s. We had to make sure there was more than 45,000 pounds in it, that was the break even point for shipping. > > Speaking of which, if anyone in Germany or beyond has something big in the > US that they want to ship and can get it to Oakland, California, soon then > let me know because Hans is shipping a bunch of stuff back to Germany but > doesn't have enough to fill a container yet. > What a great way to get something heavy to Europe. Paxton Astoria, OR

21 years, 8 months

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test-drb February 2003