28 years in a hot attic....
Posted: Sun Aug 21, 2022 4:11 pm
...and it still works!
In 1979, I purchased a Challenger 1P (while I was in medical school - I guess I needed a distraction). I really learned a lot about "modern" computers from that little device. I used a DEC PDP-8S in a High school computer class, and our college computer was an IBM that required one to create programs on punched cards to run! Although I don't have any formal electronics training, I built a number of Heathkits as a teenager, and come from a family of Electrical engineers...
I constructed a number of add-ons for the Challenger, including doubling the video resolution to 32x64 (and actually sold the instructions to do this for $8 each, making enough to pay for the computer - I'm in the First Book of Ohio Scientific by Clothier & Adams), interfacing a WWII formation control stick from a B24 to function as a joystick for games and a flight simulation program I wrote, and added a 610 memory expansion board. I also got an old IBM Selectric printer and interfaced it to be a printer/plotter. I wrote a patch for BASIC-in-ROM that added a "LPRINT" command to output to the printer. I even built a ROM burner and interfaced it to alter the monitor and BASIC ROM software.
The last time that I used it was in 1985 (I think). It went back in the factory carton and has been moved back and forth across the country at least 5 times, and has spent the last 28 years in my attic in TX (at temperatures of >120 degrees in the summer).
When I pulled it out, I wasn't optimistic that it would even power up. I bought an old Sony B&W monitor on eBay for video. I opened the Challenger case, and checked the power supplies, which were quite close to 5 volts, with no ripple. When I performed the "Smoke test", the darn thing actually booted to the "D/C/W/M" screen, but would not do anything else. Some quick checks disclosed that 37 years of disuse allowed some oxidation on the keyboard contacts, and after some cleaning, it actually booted up and I was able to write some short BASIC programs. Occasionally, it doesn't read all 24K of installed memory (probably oxidation on the memory chip pins), but I can live with that.
Now, I have to find the old cassettes with my programs on them and a cassette player (I think there may be one in the attic as well). Since I retired from clinical practice 5 years ago, I have had more time for old hobbies. Anyway, it was nice to find this site, and to know that I'm not the last man on earth with a functional Challenger 1P!
Some photos from the reanimation:
In 1979, I purchased a Challenger 1P (while I was in medical school - I guess I needed a distraction). I really learned a lot about "modern" computers from that little device. I used a DEC PDP-8S in a High school computer class, and our college computer was an IBM that required one to create programs on punched cards to run! Although I don't have any formal electronics training, I built a number of Heathkits as a teenager, and come from a family of Electrical engineers...
I constructed a number of add-ons for the Challenger, including doubling the video resolution to 32x64 (and actually sold the instructions to do this for $8 each, making enough to pay for the computer - I'm in the First Book of Ohio Scientific by Clothier & Adams), interfacing a WWII formation control stick from a B24 to function as a joystick for games and a flight simulation program I wrote, and added a 610 memory expansion board. I also got an old IBM Selectric printer and interfaced it to be a printer/plotter. I wrote a patch for BASIC-in-ROM that added a "LPRINT" command to output to the printer. I even built a ROM burner and interfaced it to alter the monitor and BASIC ROM software.
The last time that I used it was in 1985 (I think). It went back in the factory carton and has been moved back and forth across the country at least 5 times, and has spent the last 28 years in my attic in TX (at temperatures of >120 degrees in the summer).
When I pulled it out, I wasn't optimistic that it would even power up. I bought an old Sony B&W monitor on eBay for video. I opened the Challenger case, and checked the power supplies, which were quite close to 5 volts, with no ripple. When I performed the "Smoke test", the darn thing actually booted to the "D/C/W/M" screen, but would not do anything else. Some quick checks disclosed that 37 years of disuse allowed some oxidation on the keyboard contacts, and after some cleaning, it actually booted up and I was able to write some short BASIC programs. Occasionally, it doesn't read all 24K of installed memory (probably oxidation on the memory chip pins), but I can live with that.
Now, I have to find the old cassettes with my programs on them and a cassette player (I think there may be one in the attic as well). Since I retired from clinical practice 5 years ago, I have had more time for old hobbies. Anyway, it was nice to find this site, and to know that I'm not the last man on earth with a functional Challenger 1P!
Some photos from the reanimation: