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VTL-2 for Altair 680b

by billdeg
Total messages in this thread: 3
Updated: [ VTL BASIC for 680b - Working ] 06/25/2009
Just a quick note...I have been working with Grant Stockley to build and test ROMs for VTL-2. I helped test. Grant sent me a copy of the three PROMs needed to load Very Tiny Language 2 (VTL-2). Here is the current status. I put all three PROMs in place. I was not able to boot to BASIC, instead I get various inconsistent results and no "OK" prompt. Sometimes a series of 10 or so " . " characters, scroll down the screen, one per line before the system halts; sometimes just a single letter will appear, sometimes nothing happens at all. There are more details, but that's the long and the short of it. I can't get to the ACIA monitor prompt if all three PROMs are in place. I was able to use the toggle switches to check memory. Working backwards from the end of VTL-2, I found that all of the memory was intact/correct (spot checking a few dozen locations). The program is loading">... [ read more ]

Analog Computers 1961

by billdeg
Total messages in this thread: 1
The cover of Popular Electronics December 1961, featuring analog computers.
NOTE: You will need to log in (or create an account) to download these articles. In the photo above this General Electric EF-140 uses an audio signal generator to send output indicating a correct answer through a headset. The dials have logarithmic and trigonometric scales, plus squared and reciprocal scales. Best Buys in ED-EL Kits (includes some educational analog computers) by Louis Garner Jr. An Introduction Info Analog Computers by Julian Sienkiewicz Advertisement for Minivac 601 Analog C">... [ read more ]

Altair 680b (2nd)

by billdeg
Total messages in this thread: 6
Updated: [ FUA7805 in Q1 on 680 mother bd ] 06/21/2009
Two versions of the Altair 680b. The left unit has the older round toggle switches, the right has the newer flat switches. Click for larger image.
I was lucky enough to get a "new" Altair 680b, very similar to my first one, but with the expansion connector, a 680 cassette card (KSCAR), a 2P/SIO, and two hacked SWTPC MP-M 4K RAM cards attached to a 680 expansion card. To start, I am checking the IC and voltages. I am able to toggle and recall memory within the first 1K, but the ACIA in ROM slot T is not being written to memory (FF00 --). I swapped the ROM and the ACIA (6850) chip into a working system, to verify that the these chips are OK...they I started checking voltages and so far I have found a bad voltage regulator and">... [ read more ]

Heathkit H-19 Restoration

by billdeg
Total messages in this thread: 1
Thank you for Herb Johnson who helped troubleshoot and advise repair strategy I bought an H-19 terminal a while back for parts. The previous owner had started converting this computer into a sort of H-89, with power for disk drives and a cassette port. She/He did not get very far. Voltage regulators on the display control board - OK Power supply controller - bad 12-volt regulator (103). Not needed if we're just reverting to a H-19, but might as well fix if ever in the future someone wants to upgrade this to an H-89 with drives. UA78H12S0 Adjusted the yoke to align the display Serial port is marked "330-337", near the brightness knob. Now it works great, using now for testing systems.">... [ read more ]

Another VC Hacking Weekend

by billdeg
Total messages in this thread: 1
This time we were put up by Mike Lowen, who hosted the weekend. Pictures: http://sturge...ewen/Oldtech/VCW/ At a minimum,progress was made with the following 2 Heathkit H-89 Computers 1 Heathkit H-19 Terminal 1 Altair 680 - testing VT BASIC 1 Altair 680 - board repair 1 IBM 029 Card Punch Unit - Almost fixed Donner 3500 - Tubes tested and OK Attendees: Herb Johnson, Bill Degnan, Alex Bodnar and Barry Kline, Mike Loewen. Herb Johnson's page from the event: http://www.retro...m/restore/r_loewen.html">... [ read more ]

Atari 800 ... portable?

by billdeg
Total messages in this thread: 1
Well not exactly. This unit sports a handsome Casemaker travel bag.
The Atari 800 with a Casemaker travel bag. Click image for larger version.
I don't pay much attention to Atari computers on this web site, but I do think that they're a great company. I have a small project involving the restoration of the metal shields that are attached to the underside of the cartridge cover. The shields sometimes detach from the inside lid of the cartridge cover because the system's adhesive foam deteriorates.
Three 16K RAM cards and one 10K ROM card are installed in">... [ read more ]

Cataloging ESF wafer library

by billdeg
Total messages in this thread: 2
Updated: [ format wafer in 2nd stringy drive ] 05/29/2009
I am in the middle of cataloging all of my working ESF programs. I have been side-tracked by other projects, but soon enough I'll get through it all. ...a few screen shots taken during testing: I sold my spare Exatron Stringy Floppy drive on Ebay last week. What's next... Using TRS 80 Model 1 1. Implement a method for converting wafer contents to cassette (Users guide has instructions) 2. Implement a method for converting wafer contents to disk The issue with #2; you can't have the expansion unit and the ESF operating at the same time because they use the same expansion port. So what I believe you have to do is set up two TRS 80's and share one cassette drive. The first TRS 80 will have the stringy floppy and the cassette, the 2nd will share the same cassette (using a switch box) player and wi">... [ read more ]

Hobbyist Computerized Bulletin Board

by billdeg
Total messages in this thread: 1
I have posted a scan of the Nov 1978 Byte Article (page 150) Hobbyist Computerized Bulletin Board by Ward Christensen and Randy Suess This is the important article about the famous CBBS/Chicago BBS - Considered the first home brew BBS. http://vintageco...0ward%20christensen.pdf">... [ read more ]

Old Timer's Day at PACS

by billdeg
Total messages in this thread: 2
Updated: [ Slides from Meeting ] 05/17/2009
The Philadelphia Area Computer Society cordially invites the members of MARCH to: "Old Timer's Day" Saturday, May 16th 2009 Super Giant food store Community Center, 2nd Floor 315 York Road Willow Grove, PA 19090 With a special guest appearance by: Bill Degnan from 12 to 1 PM. There will be tables set up for folks to demonstrate their vintage computers after Bill's talk. For further information go to: Please plan to attend, to make this a very special day. Thanks, Ron Kushnier ">... [ read more ]

Landenberg Today Article

by billdeg
Total messages in this thread: 1
Yours truly is on page 86 http://www.bluetoa.../publication/?m=507&l=1">... [ read more ]

Another 5150 Restoration

by billdeg
Total messages in this thread: 1
Today I got an IBM 5150 B in the mail. It was absolutely filthy. There was a layer of dirt-turned-crud covering everything. There were playing cards stuffed in the B drive and an old disk in the A drive. The system did not power up. I almost gave up right then, but .. I took out all of the cards (CGA, AST SixPak, IBM floppy drive controller) and then cleaned everything as well as I could. Powered up - fan started, long beep two short beeps (missing/bad display). Ah, it must be one of the cards shorting out the power supply. Correct - It was the display card. I replaced it. Put everything back in to the slots. Powered up - fully functional. I cleaned it to "excellent" condition with a magic eraser, paper towels with soap and water, q-tips for the keyboard and drives. Another computer saved from the dump. ">... [ read more ]

Landenberg Hack Weekend

by billdeg
Total messages in this thread: 1
Dan R and Bill Dr #3 came to my house this weekend. A lot was accomplished. We worked on an Northstar Horizon and used it to match a 2nd backup drive and controller card for use in another system. IMSAI 8080 - Dan demoed how his system boots to IMSAI BASIC from PROM which can load programs from simulated terminal input, and he demonstrated his modified a lunar lander program to land on autopilot. Altair 8800 We made a copy of the Altair Monitor II using a DOS-based EPROM burner and Dan's IMSAI 8080 for testing it. The monitor is patched to use the Altair SIO-2 controller but we did not quite get either cards on hand running properly. We put the EPROM on a 64K Tanner RAM/ROM card and it appears to work correctly on a front-panel system. I anticipate that we will be able to install on the Altair when it's ready. We also identified and replaced a slew of bad front panel chip">... [ read more ]

EC-1 Falling Body Program

by billdeg
Total messages in this thread: 3
Updated: [ EC-1 Video with Tektronix 7313 ] 04/18/2009
The Heathkit EC-1 wired for the "falling body" program.
This weekend I worked with Bob Grieb, Dan Ragonti, and Mike Lowen to test the Heathkit EC-1 computer. We made it all of the way to the first exercise in the user guide - the falling body program. Bob and Mike brought tube testers and fortunately the tubes were all OK. We cleaned all of the plugs and connectors with soap and water. Dan hooked up a Variac in series with an incandescent light as a current limiter, so we could monitor the reaction of the EC-1 to current load. Bob used a volt meter to test the electronics and cleaned up a few things (solder joints and a loose wire), but nothing major was needed to get the old girl back up in running">... [ read more ]

CISC/CPEG 367 scheduled

by billdeg
Total messages in this thread: 1
Today I learned that I am scheduled to teach another semester at the U of Delaware. Please sign up for my class! Contact me if you have questions. http://pri...8&session=1§ion=010">... [ read more ]

year of Lanier models?

by cledger1
Total messages in this thread: 2
Updated: [ Lanier 103 ] 04/16/2009
Does anyone know the year of the Lanier model 103 word processor? Was is available more than one year?">... [ read more ]
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