DATA I/O 21A

[frank]

Hello all,
really trying my luck here: does anybody have a DATA I/O 21A (E)EPROM
programmer and can help me with some tests to understand if mine is working
well? It appear to program most common EPROMs just fine but failed on the
uncommon MCM68764 which I believe is good instead (but I have only one...).
Sure, the MCM is a 1980 vintage, but it was NOS.
Anyone?
Thanks
Frank IZ8DWF

 

[frank]

More informations, so I answer to myself just for the record:

frank <frank@invalid.net> wrote:

It appear to program most common EPROMs just fine but failed on the
uncommon MCM68764 which I believe is good instead (but I have only one...).
Sure, the MCM is a 1980 vintage, but it was NOS.

I confirmed it is more likely a bug into the programming algorithm for the
MCM68764/68766 EPROMs.
If I interrupt the programming after the first pass, the EPROM appears to be
programmed just fine.
Otherwise it makes 20 programming passes from 0 to 1FFF and throws some
error. The datasheet for these EPROMs just suggests a simple 1ms write pulse
for every address and retry on the same address if not read correctly, so
I'm not sure why this programmer should redo all addresses from start
for 20 times before giving up.
It might be an hardware fault but so far the programmer worked fine on all
the 27xxx EPROMs. Also it reads fine the memory and can correctly test
for blank of course.
I'll try some more exotic models like the 2532 soon.

> Anyone?

I guess it's not so widespread by now.

Thanks
Frank IZ8DWF