OT Troubleshooting: Old computers with modern parts

woodelf wrote: Actually, it's possible to build a reader fairly easily. I liberated read mechanisms from Remex "Director" readers I picked up cheap on eBay, and built a microcontroller stepper controller/serializer (which was fairly trivial-the power to the stepper is done with 0-brainer power FETs; it was not difficult to reverse engineer the connections to the head). The smallest one I built is not much bigger than the read mechanism itself, and runs on an old laptop power supply. It will do only about 60 CPS mostly due to power limitations, but how fast can you handle tape (I have reeled units that I built serializers for also). All of the readers and mechs that I have are industrial strength, and I beleive that in home use the mechanisms will last essentially forever (certainly longer than I will). Older Remex's used now-unobtainable lightbulbs, which I have replaced as needed with high-power LEDs (the "Intel" readers used Remex mechanisms). The oldest reader I have is an Oktronics (NIB) which had a very special (and broken) lightbulb. The #$@$#@ lightbulb cost $42-I couldn't bear hacking LED's into it. It is possible to build a "slot" type reader with LED's and photodiodes; I built one but abandoned it when I built the mechanized units because they are "neater". The real problem in a paper tape "ecosystem" is in the punches, "handling equipment" and the tape itself; I got lucky and got a lot of Mylar cheap some time ago, as well as some real DEC fanfold and reel tape. Mylar tape is now fabulously expensive at retail. The older DSI punches are very rebuildable; I got a very beat-up one in, replaced the belts (standard) and the caps in the power supply, made a replacement chad box from a $2.00 radio shack project box and some Velcro and it works great. If the electronics fails (I think that they use an F8 microprocessor) I'll just replace it with work-alike modern electronics. I have a FACIT reader that was severely damaged in shipping, but it has a good punch head. I intend to make a smaller case for it and run it with a microcontroller and FETs; I think I can reduce the power requirements by only punching one hole at a time (obviously, it will be slower, but who cares). Most of the size/weight in the thing is in the colossal linear power supply. Again, this mechanism in home use could last a very long time. Paper tape is a PITA and fun at the same time. I like to point out to friends that the data on the metallized Mylar tape will be readable (even visually!) and usable long, long after their hard disks are very deep down in landfills! -Steve Loboyko Website: http://juliepalooza.8m.com/sl Nixie Watch (one-tube):http://juliepalooza.8m.com/sl/complwatch.htm __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com