PGS.G.EH%MIT-OZ@MIT-MC.ARPA (06/14/84)
From: Edward Huang <PGS.G.EH%MIT-OZ@MIT-MC.ARPA> Hello, I have a Sylvania F6T5BL "black light" tube, it gives off a purpulish glow... It doesnt seem to erase my EPROMS but is the same kind used in that BYTE article. Could it be that programming an EPROM several times require longer erasure times???? or do I have the wrong UV tube? In any case, the idea of UV light, +25v besides blown eproms and melted power supplies is making me go toward the new EEPROM (Seeq and Xicor +5v EEPROM) -- does anyone know how to order these things from the distributors, often rude and only cater to orders of 10000's ?? thank very much -Ed -------
W8SDZ@Simtel20.ARPA (09/24/84)
From: Keith Petersen <W8SDZ@Simtel20.ARPA> There are two different kinds of ultraviolet tubes available--short wave and long wave. The kind used to illuminate posters, etc. are long wave. The kind used to erase EPROMS are short wave. Short wave UV is the component of sunlight which causes tanning (and sunburn, and skin cancer), so you have to be very careful not to look at a short wave UV lamp. I've been using a General Electric G8T5 8-watt germicidal tube with very good results. If you want to build an eraser from scratch then you'll also need an 8-watt ballast and an FS-5 starter. There are some back issues of BYTE magazine which describe the construction of an EPROM eraser. However, at least one of these articles INCORRECTLY suggests using a long-wave UV lamp. The easiest way (and probably cheapest way) to build an EPROM eraser is to buy the G8T5 tube and put it in an inexpensive fluorescent desk lamp which already contains the correct ballast, starter, sockets, cord and power switch. Good luck and have fun. Let me know if you need more information. Tom Libert Dept. of EECS Division of Computer Sci. and Engin. Univ. of Michigan Ann Arbor, MI 48109 (313) 763-6474