UV eraser boxes are expensive, the sun takes too long, i was wondering if a black light were to do the job? Woudnt be very fast, but would be faster than the sun surely.

It won't work, the wavelength from black light tubes is far too long to erase EPROMs.

The cheapest way is to buy a 6 inch eraser UV tube and make your own interlocked box, an old mechanical timer from a microwave is ideal. In fact if you have a broken microwave you could use the whole thing, just remove the magnetron & transformer and put the UV tube and ballast in there instead. The glass door should block the UV. 8^)=

Lee.

dang.

I've been using the Datarase II made by Walling Co., which I got several years ago for $40. Although it has always needed about 12 minutes to erase my EPROMs instead of the 3 they claim, still it has been quite satisfactory and I would recommend it if it were still available. Unfortunately it apparently is no longer in production. With a quick search I did however find that The Byte Factory http://www.thebytefactory.com/ is selling a similar one for $50. I was hoping to find you another $40 one, but it can almost still be said that if you can afford a soldering iron (not counting the disposable ones), you can afford an eraser.

Hi Garth,

I also have this same eraser. I have found that the time required to erase an EPROM is greatly dependent on its manufacturer and age. Most of the EPROMs that I use in current projects are fairly recent and the 12.5V variety. These typically erase in about five minutes.

However, I have many in my older stock, usually the 21V+ types, that take about fifteen minutes or so. As a general rule, I usually let all of my EPROMs erase for about that long, to avoid hassles with partial erasures and programming errors.

An EPROM emulator was probably one of the best investments I ever made. Eliminating the burn-erase cycle speeds development time (and enjoyment) immensely.

Regards,
Mike

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- Mike Naberezny (mike@naberezny.com) http://6502.org

After I wrote "12 minutes" I realized that was an understatement and it did actually take longer. (After having set it years ago I just go by the end-of-cycle beeping now, so it's easy to forget the actual amount of time.) I use the same amount of time for everything for the same reason you give, although I don't know if I've ever had a 21V EPROM in it. When I first tried it (on 12.5V CMOS ones, IIRC), the EPROM would quit verifying in 8 or 9 minutes, and they tell you to double that amount of time for the total. Now I mainly use it for PIC microcontrollers since most of them are still EPROM-based. The 8-pin ones almost fall into the holes over the UV tube, but there's no problem.

thx.

A friend found an EEPROM in his junk box and has offered to order some in from the US. anyway, thx.

> A friend found an EEPROM in his junk box

Ah yes, a junk box. How we forget the simple days in the apartment when everything had to come off the kitchen table and go back in the box to clear space for a meal.

That was before the home office with over 2,000 ICs, 50 shelf-feet of data and reference books and catalogs, three file cabinets and a four-drawer flat file, a large closet full of related stuff, 400 little drawers of parts including 1/4 million resistors, two cluttered desks, an equally cluttered 8-foot electronics workbench, and scores of projects everywhere, some never finished and others that made it to production in our company and are flying in aircraft all over the world. The garage is extra, with too many junk boxes to count.

Let's see-- you were looking for something, weren't you? Oh yes, an EEPROM. I think the only ones I have are serial !

lol, sounds like a place i'd be quite happy in, and what i'll probably end up with.

Serial eeproms, little 8 pin packages. Try using them for a 6502 though. They sell them at Jaycar (in Australia) but not the parallel ones. I'll have to get some from the states. Hmm... US$5 approx a piece, i'll want two plus about US$20 international s/h. The Australian dollar gets about US $0.78 now. Hmm.... a little expensive for 16k of EEPROM.

Or I have a 32 pin 28c512 here, which I'll only use 8k of, perhaps 16 if needed. Just ground a few address lines.

That's all?!?!?!?!?!? Not much of a hobbiest are ya? If I had the money I buy a 100 acre warehouse and stock the thing from floor to ceiling with all the crap I currently have in my house... Then I'd buy an equally big office just so I have space to work on my current project. LOL... seems our hobbies have a way of growing out of control. One day I hope to use ALL of this stuff to build ONE massive (and that's an understatement) computer.
Anyone else game? LOL
Lyos Gemini Norezel

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Mundus Vult Decipi et Decipiatur

I sure am. Make a 128-bit computer compleatly from TTL chips. I am suprised the ammount of people who make computers from TTL too. There are some good designes out there.