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
walker@hplabsb.UUCP (Rick Walker) (09/25/84)
<> I am looking for the source to a 6502 system monitor for a small controller project I am working on. Since the hardware will be special purpose, I am willing to heavily modify the source file. I would like to see the following features: Memory examine/deposit Trace of program flow Breakpoints Register examine/modify Downloading of Intel hex format object code Jump to address If I can't find one, I'll have to write it - so any help is appreciated. Please reply to me and I'll send a summary (or a listing) to anyone who requests it. Thanks in advance, Rick Walker (...!hplabs!hplabsb!walker)
henry@utzoo.UUCP (Henry Spencer) (09/27/84)
> 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 > ... 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. The first part needs emphasizing in relation to the second part. The commercial EPROM erasers are carefully designed to make it very hard to get even a glimpse of the UV. SHORT-WAVE ULTRAVIOLET CAN CAUSE SEVERE PERMANENT EYE DAMAGE!! If you do build an EPROM eraser using a desk lamp, be very careful when using it. And for heaven's sake don't leave it lying around looking like an innocent desk lamp! When you're not using it, take the UV bulb out and lock it up somewhere. A nice big "DANGER" label next to the power switch would also be appropriate. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry
david@bragvax.UUCP (David DiGiacomo) (10/11/84)
>>The commercial EPROM erasers are carefully designed to make it very hard to >>get even a glimpse of the UV. All of the low-end ($100-200) commercial erasers I've seen leak UV in every direction; they're much worse than the typical hobbyist's coffee-can kludge. This isn't a problem because real engineers aren't afraid of a little UV! -- David DiGiacomo, BRAG Systems Inc., San Mateo CA (415) 342-3963 (...decvax!ucbvax!hplabs!bragvax!david)
crandell@ut-sally.UUCP (Jim Crandell) (10/11/84)
> This isn't a problem because real engineers aren't afraid of a little > UV! I sincerely hope that a smiley face was unintentionally omitted from that remark. Let's ignore for a moment the well known effects of UV-induced skin burns, more because they are more or less properly associated with fairly high levels of exposure than because ``real engineers'' obviously aren't afraid of a little cancer, either (why else do so many of them smoke? [:-)]). Since the fact is evidently new to at least one reader of this newsgroup, I don't feel the need to apologize for reporting that short-wave UV radiation is also known to be responsible for the development of brown cataracts. Ladies and gentlemen, I am not referring to pollution in Niagara Falls! Does the idea of impending blindness appeal to you? Ever wonder why that germicidal lamp costs N times as much as a fluorescent lamp of the same size? Look at the envelope. It's clear. It's very clear. It's very, very, very clear. The idea is that every #$&^!@% photon that discharge somehow contrives to create is gonna make it through that glass. AND YOU'RE GONNA TURN THAT STUFF LOOSE ON YOUR EYES?!!! Commit yourself to the nearest mental hospital at once! -- Jim Crandell, C. S. Dept., The University of Texas at Austin {ihnp4,seismo,ctvax}!ut-sally!crandell
jans@mako.UUCP (Jan Steinman) (10/12/84)
Be wary of the "exposure to sunlight" trick. I don't have the manuals in front of me, but the little holes must be forced deep into the depletion region or >the zeros might come back<!!! I have verified this myself by being impatient at erase-time, which cost a hundred times what it saved at debug-time, when random ones started, intermittantly, no less, slipping to zero! Follow the manufacturer's spec for erasing -- it'll save problems in the long run. -- :::::: Jan Steinman Box 1000, MS 61-161 (w)503/685-2843 :::::: :::::: tektronix!tekecs!jans Wilsonville, OR 97070 (h)503/657-7703 ::::::