[Coco] MPROM woes (cured)

[Roger Taylor]

At 09:08 PM 11/15/2008, you wrote:


> > I tried 4 9v batteries a few days ago and for some reason it wouldn't

> > work.  That is, the software kept reporting a no-go on the first

> > write cycle.  The EPROMs remained blank.  Maybe it was just some of

> > the batteries in series holding up the rest, as I didn't check the

> > total voltage.

> >

>

>There remains the possibility that those 4-battery EPROMs you tried are now

>fried, and are not only blank but now unprogrammable.

>

>Art




I'd be willing to bet that the little regulator IC would cook instead 
of the wrong voltage getting through it.

The EPROM I was trying to program (and failed) is a 68X6048 which I 
thought was the same as a 2764 but turns out to be a 27512 (64k x 
8k).  It appeared to read well but not program.

I've got 25 of the 27512's and unless I can pin-wire them to act like 
a 27256 or below, they're useless in my CoCo projects.

-- 
Roger Taylor

http://www.wordofthedayonline.com