Search Posts:

Latest Projects:

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 ]

Bunch of little things

by billdeg
Total messages in this thread: 1
1) I built from parts two more IBM systems, one IBM stock dual drive 5150 PC and an IBM XT 5160. The XT has a ST 412 HD, with AST Six Pak. - 640K RAM and 10MB - who could need more than that? I put IBM DOS 3.3 on the HD. 2) I got my Northstar Horizon to boot using the ADM 3A terminal. 3) I have been able to successfully type in a lot of programs into my IMSAI lately (using CUTTER monitor program), and the system holds long enough to complete and run the program. 4) EC-1 - New oscilloscope and pictures of underside wiring">... [ read more ]

Reforming Electrolytic Capacitors

by billdeg
Total messages in this thread: 1
Originally posted on Midatlantic Retro Yahoo Group: - In, Mike Loewen wrote: > > > I tore apart my IMSAI in order to remove the four large electrolytic > capacitors for testing/reforming. There are two 9500uf-30VDC caps and two > 95000uf-15VDC caps. Here's the rig I put together for bringing them back > to life: > > http://sturgeon.css.psu....I/Reforming-L.jpg > > I put this together after reading many documents about testing old > capacitors. Hidden behind the cap is an 8K power resistor in series with > the cap. The small meter is measuring the voltage output from the the > power supply (a HP 6443B 0-120VDC/2.5A unit), in this case 25.0 volts. > The large meter is measuring the current flowing through the cap, 0.11ma. > The voltage across the cap is 24.7V at this point. > > I started">... [ read more ]
OLDER POSTS (15 threads per page): 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 |


Buy a Commodore Computer Poster

Popular Topics and FAQs

  • Commodore B Series Tips and Tricks
  • Aerocomp TRS 80 M 1 Expansion Unit DDC
  • Items Wanted
  • Lobo Max 80
  • Zenith Z-19-CN
  • Prototype PET 2001 photo
  • Using Toggle Switches to Analyze Memory
  • Commodore Disk Archive Project
  • PET 2001 Prototype at Gametronics 1977
  • Jim Butterfield Photo
  • IMSAI 8080 With Processor Tech. Cutter
  • Secrecy is the keystone of all tyranny
  • Cromemco System Three
  • Northstar Horizon - Boot Problem
  • Computer History and Restoration Links
  • Commodore BX-256-80 - 8088 Co-processor
  • S-100 board testing with Z-80 ICE
  • Donner 3500 - an early portable computer
  • Digital (DEC) PDP 11/05 NC Assembly
  • Univac 1219 rescue
  • Fido BBS listing node list 6-13-1986
  • PDP 8e
  • MITS 88-2 SIO (2SIO) for BASIC
  • Visual Technology Inc Model 1050
  • Amiga 2500 Restoration
  • The Evolution Of IBM Computers
  • Replacement teletype print hammer head
  • Archiving and Copying Software 101
  • Computers Built 1940 - 1950
  • CBM B-520 (a.k.a B256-80 or B500 256)
  • RCA COSMAC Microkit
  • Commodore 64K C-116 Mods
  • MITS 8800b Turnmon 9600 baud
  • Catweasel, 8in and 5 1/4
  • Raspberry Pi as Gateway to Internet
  • Digital PDP11 late 1969 early 1970
  • PDP 11/40 72 inch cabinet model
  • PDP 11/40 Industrial 11 model
  • Digitial MicroVAX 3100 30 System
  • Digital VAX 4000-200
  • Commodore 64 / 1541 DRIVEKNOCK
  • Booting the System Using RL02 drive
  • PACS: Reflections by Kathleen Mauchly
  • Tele-Graphic Computer Systems Inc.
  • Commodore B Series SID Jukebox?
  • Installing Core into PDP 11/40
  • Setting Up OpenVMS 7.1 DNS CLERK
  • Felt-Tarrant Comptometer Model J
  • NextStation Color
  • Digital Rainbow (PC100-B2)
  • 1970 Compusad Compulogical Tutor
  • Archiving Papertapes Using DSI NC 2400
  • 1976 P.C.C. Features the MAI JOLT 6502
  • 1961 Beckman DEXTIR Computer
  • UNIVAC 1 and UNIVAC File Computer 1
  • Past Issues:

    Visual 1050 operation

    This image was selected at random from the archive. Click image for more photos and files from this set.