Search Posts:

Latest Projects:

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 ]

IBM PC 5150 Dump a BIOS using

by billdeg
Total messages in this thread: 3
Updated: [ Another 5150 A BIOS DUMP ] 04/04/2009
This is a mirror of the original page C:> DEBUG -N MYF000.BIN (resulting file will be named MYF000.BIN) -R BX (set BX=0000H/CX=8000H as count of bytes to write, 00008000H = 32K) BX 0000 :0000 -R CX CX 0000 :8000 -M F000:0 8000 0100 (copy 32K bytes from F000:0 to offset 0100 in local segment) -W 0100 (write from offset 0100 in local segment) Writing 8000 bytes -N MYF800.BIN (resulting file will be named MYF800.BIN) -M F800:0 8000 0100 (copy 32K bytes from F800:0 to offset 0100 in local segment) -W 0100 (write from offset 0100 in local segment) Writing 8000 bytes -Q C:>copy /b myf000.bin+myf800.bin final.bin (optional, concatenates together the two myfxxx.bin files into final.bin)">... [ read more ]

Another IBM 5150 16KB-64KB CPU

by billdeg
Total messages in this thread: 1
I traded a working IBM 5150 with 64KB-256KB CPU for an earlier (but not working) 16KB-64KB CPU Model.
This is a 10/1981 model, without the IBM-labeled disk drives. I have not yet confirmed that IBM sold systems with non-labeled drives, or whether these were added by the reseller to save money. The date stamp on the IC's of the drives range from 1980-2nd week of 1982, and one could theorize that the drives were added later, after market. That explains why they're not "IBM" labeled. Just my hunch.
I swapped out a working 16KB-64KB CPU board and brought the system back to life. The drives work, I did not test the CGA card that also came with it. The previous owner had both a monochrome and CGA card installed, which may have caused the motherboard to short out. Not sure. A">... [ read more ]


by billdeg
Total messages in this thread: 1
My personal favorite 8088 GRiD laptop is the Model 1040 GRIDLITE PLUS.
The GRiD 1040 had a blue on blue LCD display. This specimen has both the internal 3 1/2" 720 disk drive and an external model 3402 5 1/4" drive.
This laptop came out in 1988, but I recall seeing this model in service as late as 1993. Unfortunately the power supply was poorly designed. Many still-functional system exist if you can find a working power supply for it.
The GRiD external 5 1/4" disk drive required it's own separate power supply.
DOS is stored on a ROM, and the version is 3.21. The ROM drive is "A", the internal 3.5" disk drive is "C", and the external 5 1/4" dr">... [ read more ]

New blog on (some) rare and old computer

by cyberfritz
Total messages in this thread: 3
Updated: [ Spreadsheet version: yes ] 03/31/2009
Dear all, if you like this blog, you might want to consider also this (I admit it, my) blog: A major contribution (at least that's what I hope) of it is my Ebay prices list of some rare computers together. The blog is all about some rare computers, about the rarity of old computers, and mostly theoretical thoughts about collecting rare computers. In contrast to this excellent blog, you won't find technical how-tos or technical tips and tricks. I'm looking forward your visit. Regards, cyberfritz">... [ read more ]

The Bouncing Beastie

by billdeg
Total messages in this thread: 1
The Bouncing Beastie by Martin Winzenread appeared in the September 1976 Dr. Dobbs Journal: http://vinta...Demo%20Program.pdf I typed in a version that will work on the Processor Technologies' CUTER program with the VDM-1">... [ read more ]


by billdeg
Total messages in this thread: 1
Evan gave me a GRiD GRiDPAD 1910 laptop without a power supply. Using another GRiD powersupply that feeds 17.25V I was able to boot this system.
The GRiD GRiDPAD 1910 touch-screen laptop.
The touchpad has some bad spots, but I was able to look around. There are three drives, all stored in ROMS, no disk drives. Pictures of GRiD laptops">... [ read more ]

Hacking Weekend

by billdeg
Total messages in this thread: 1
This weekend a few friends from the MidAtlantic Retro Computing Hobbyists came by to work on old systems. Here are a few pictures.
Moving a wheel barrel full of TRS 80 Model II's Click image for larger picture.
Dan Ragonti was able to almost get his PET 2001-8 working by swapping parts from a working PET for comparison purposes, and replacing RAM. PET 2001-8 pic 1 PET 2001-8 pic 2 PET 2001-8 pic 3 ">... [ 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 |


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:

    Dupont Metal Tape

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