I don't know - though I note the suggestion elsewhere to put a
magnifying glass over the top of the chip (hmm, does ordinary optical
glass actually bend UV light?).

The tube I use is I think 30W and about 9 inches long. It is a powerful
UV emitter used for water decontamination and someone gave it to me but
I think they can be purchased for around $50 or so - they are used also
as germicidal lamps - check your yellow pages.

Caveats

1. Make sure you shield it so you won't ever look at it - it is very
powerful and would probably not do your eyes a great deal of good.

2. Ensure you use such a tube in a well-ventilated area as the ozone
produced is quite substantial - this is, indeed, why these tubes are
used for their intended purpose.

That said, they sure do erase PICs very nicely. Ensure the chip is
securely mounted in conductive foam, of course. I have certainly erased
several code-protected 12C509 devices  - they erase in around 1 minute
under normal circumstances and take around 10 mins if code-protected.

> ----------
> From:         Alex Holden[SMTP:alex_holden@GEOCITIES.COM]
> Reply To:     pic microcontroller discussion list
> Sent:         Sunday, January 04, 1998 12:39 PM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      Re: PIC versus AVR
>
> > A sufficiently powerful UV eraser *will* recover windowed parts - I
> > speak from experience. One used for water disinfection is ideal -
> watch
> > the ozone production, though. They are not particularly expensive
> and
> > will pay for themselves after a couple of boo-boos protecting JW
> > devices.
>
> I have an ordinary 8W eraser. Do you think it would recover a 16c74/JW
> device if I left it in for long enough (I think I did try it for about
> two
> hours before giving up and throwing it in a drawer).
>
> > > The PIC is popular, since it works well, is cheap, can be
> programmed
> > > with $5 worth of parts, and is practically indestructible (except
> if
> > > you goof while programming it; the programming circuitry is touchy
> and
> > > its <BLEEP> code-protect fuse can easily convert expensive window
> > > parts
> > > into $20 tie pins.
> > >
>
> ----------------------------------------------------------------------
> -
> : Alex Holden- Electronics student, Caver, and Land Rover enthusiast.
> :
> :        http://www.geocities.com/CapeCanaveral/Lab/1532/
> :
> :            Linux- The choice of a GNU generation.
> :
> ----------------------------------------------------------------------
> -
>