[Coco] EPROM eraser wanted

Gene Heskett gene.heskett at verizon.net
Sun Apr 16 01:02:31 EDT 2006

On Saturday 15 April 2006 14:36, Stephen H. Fischer wrote:
>If you have a good lighting store around, you can try and order just
> the lamp tube.
>Then you can put the lamp in place of the regular florescent with the
> same size in any suitable fixture.
>The EPROM eraser is just an ordinary florescent tube with no interior
> white coating.
Correction, its made from quartz, as the glass filters quite a bit of 
the UV light needed to erase an erasable eprom.  I once taped a 27C64 
to a "black light" tube, removing it once a day to check to see if it 
was erased.  It took about 2 weeks to get the last bit set to a 1, and 
apparently that wasn't enough as subsequent programming sessions left 
bits that shoulda been a 1 at zero when done.  So I ordered an eraser, 
which did that job in 18-20 minutes.  No more ghost zero's in my burns, 
with a homemade burner I'd built.  ISTR I paid about $70 for it at the 

>It is clear glass with small balls of mercury inside.
>You do have to use it in a way that you cannot look at when it is on
> as it will harm your eyes.

The eraser I have at the tv station is quite small, pack of cigs size, 
and its sliding lid is interlocked so well I've never seen the lamp 

>The one I have is marked "G8T5...".
>That is : "G8T5" followed by three dots (...) and a warning to avoid
> the rays.
>It may be listed under "Germicidal" in the lamp catalogs.

That one should be a quartz tubed lamp, most of the germicidals were.
I have NDI how long it will take it to wipe a 2764 though.  It takes 
more than the minimum to get all $FF's out of it, but it can be 
overdone according to my reading on that quite a few years ago now.  
The effect is that eventually it won't program regardless of how many 
write pulses you bang it with.

>Stephen H. Fischer
>Roger Taylor wrote:
>> I'm looking for a used EPROM eraser, doesn't matter how old or ugly
>> it is, as long as it works.  Also a 21v power supply if somebody can
>> dig one of those out of your parts stash.  Bare wires at the end is
>> ok because I will be soldering it to a 2-hole header for plugging
>> into the Disto EPROM programmer.
>> If you donate it towards the CoCo3.com efforts to create new
>> products, I will return a Portal-9 or Rainbow IDE registration, or
>> if you want cash let me know your asking price.
>> I also want to ask other developers what the most common or popular
>> Windows-based EPROM programmer might be so I can start looking into
>> adding support to my IDEs.  I definatetly want to let the users burn
>> their software to ROM right from the IDE if they are creating those
>> kinds of images.

Figure on spending about $800-$1000 or more for a windows/dos based 
solution in the one size fits all category.  The one I have at the tv 
station can be adjusted in the driver to burn virtually any of the 
eproms that were popular up to about 6-10 years ago.  But as I'd never 
bought the extra socket adaptor kits for the newer stuff, I haven't 
updated it in quite some time, 7 maybe 8 years now.  Its brand name was 
"Super"-something I've long since forgotten.  I bought it at the time 
to fix a problem in a video effects device that the maker wouldn't.  
And I did fix it...  And a couple of other things while I was at it.  
OTOH, the one I made, nearly 30 years ago now, I think I might have had 
a $30 bill in it.  The most expensive piece was the ZIF socket, which 
was about a tenner.

>> --
>> Roger Taylor

Cheers, Gene
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