On 2017/04/03 3:18 PM, wrote:
On Mon, 3 Apr 2017 12:35:41 -0700, John Robertson
wrote:

On 2017/04/03 11:20 AM, mike wrote:
On 4/3/2017 10:21 AM, John Robertson wrote:
On 2017/04/03 9:59 AM, tom wrote:
wrote in message
...
The EPROMs in one of my machines are at least 32 years old. Reading
online about EPROMs it seems that maybe my old devices are nearing the
end of the life of the memory contents. So I'm thinking I should copy
or have copied the data in these old devices. Am I right?
Thanks,
Eric

Definitely make a copy. Then program a second copy of the EPROMS and
swap
them in to confirm the copy. If the copies are good, erase and
reprogram the
originals and keep as a spare.

Also replace any memory backup batteries while you are there.

You will probably be dead before you need the copies.



EPROMs are quite stable in my experience, however backing up and using
the second set of EPROMs to run the product seems reasonable if a bit of
overkill. Make a copy, archive it off-site and keep your burner in a
safe place. I would simply use the originals until they gave me cause
for doubt.

Also - do not erase the originals, simply reprogram (refresh) them after
telling the programmer that the chips are not blank.

I'd like to hear the theory behind that.
Are you saying that a failed bit is never zero?
Is programming a zero to zero the equivalent of twice the
program pulse width? Is that less stressful than an erase?

EPROMs have a
limited number of erase/burn cycles so why knock one cycle off? I do
find that a number of originally good EPROMs (that had valid data) fail
to reprogram after being erased.

If it's that close to failure, wouldn't you want to learn that now?

No, if the thing is working why bother? Erasing and reprogramming
doesn't prove anything and your burner may not do as good a job as the
factory's rather expensive EPROM burner - which was likely a DATA 1/O 29
series with Gang Pack or possibly the DATA I/O Gang Programmer model 120
(early 80s).

http://www.dataio.com/Company/About-...iversary/1980s

In other words the erase and reprogram could result in a less reliable
part than it was originally. I don't bother to refresh EPROMs, nor do I
replace them until they fail. Seems pointless to me to do anything
beyond double archiving the data.


I burn many classic EPROMs (2716s and up) and PROMs a month, so have
some experience in this matter.

John :-#)#

I understand the desire to do whatever you can to keep old equipment
working,
but this is getting mighty close to, "if it ain't broke, don't fix it."

There is a awful lot to be said for "if it ain't broke, don't fix it.".
I see many game boards and arcade games where the owner thought it was a
good idea to replace things that were still working. This sometimes
results in an unrepairable (too many mistakes = too many hours to
repair) game as they have made too many mistakes.

John :-#)#
Greetings John,
I just went through three weeks of frustration fixing this machine
tool. The control maker, FANUC, said the problem was most likely not
any part of the control. The lathe maker, Miyano, who married the
control with the lathe said the problem was not likely to be on the
machine side. The guy I spoke with at Miyano said that the lathes
hardly ever need major work because they are so well built. And he is
correct. The machine is a great machine. So good in fact that it would
be worth it to put a new control on the thing if the old control
failed. The problem turned out to be a circuit board that interfaces
with the lathe. I bought a used board and swapped the EPROMs and now
the machine is running again. FANUC says that the EPROMs on the board
are hard to find replacements for so I want to get copies made. Since
you copy many a month I was wondering if you do this service for
others or just yourself. It might be less risky to pay and expert than
to do the copying myself.
Eric


Hi Eric,

I do archive EPROMs ($15US each plus shipping) however there are a some
potential risks in shipping them to me.

1) My shop is in Canada - and Fedex/UPS/DHL all charge my shop customs
import fees that can reach $40US. We normally have Americans (I am
assuming you are in the USA) ship stuff to us by US Post as the import
fees (if that happens) is around $7US.

2) Stuff gets lost in transit. Rare, but can you afford to lose the EPROMs?

3) Handling. Do you have anti-static foam and an anti-static bag, or IC
anti-static tubes that you can ship these in?

What city are you in? I can ask on the Data I/O mail list to see if
anyone in your city can help you. Likely a small case of beer or bottle
of wine would suffice for that person...

John :-#)#

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