[Techtoolslist] EPROM Programming Woes...

[Andy Raven]

Hi,

Have you tried smaller Eproms to see if they have they same issue?
It could be a number of issues:
- Does the 29B use the fast programming method (or similarly named) process
for those particular eproms? Or the slow default method?  If the former,
can you manually change it to use the early slow method to see if the
problem persists?
- If it supports and uses fast programming, it's worth taking a measurement
of VCC to make sure it's increasing it from 5v to 6, 6.25 or 6.5v
(depending on the chip) correctly.  Some programmers claim to support fast
programming, but don't actually increase the VCC voltage as per the
datasheet.  This still works on eproms in reasonable condition, but on
older ones it often doesn't work.

If it was a communication problem, I would imagine it would fail in the
blank check test sometimes too.

Andy

On 28 March 2018 at 17:33, Joe Magiera <joemagiera at ameritech.net> wrote:

> Jess,
>
> I have an EE Tools Top Max and I often have the same problem.  What I have
> noticed (and I could be way wrong here), is I think my cable between my
> programmer and PC is suspect.  It seems like for short/quick things (verify
> an EPROM is blank, or do a read of an EPROM), it works fine.  But for
> anything longer, something hangs up and the programming effort of that
> EPROM
> is screwed up.  But then if I have the cable as straight as I can, or just
> one nice large smooth curve, it will work fine and I can program 20 EPROMs
> in a row with no problem.  But then I bump or move the cable and the
> programming will abort or hang up.
>
> Just sharing my experience.  It would seem obvious to me to try a new
> cable,
> but as yet, I haven't done that (go figure).
>
> Joe
>
> -----Original Message-----
> From: Techtoolslist [mailto:techtoolslist-bounces at flippers.com] On Behalf
> Of
> Jess Askey
> Sent: Wednesday, March 28, 2018 12:01 AM
> To: Technical Tools Mail List
> Subject: [Techtoolslist] EPROM Programming Woes...
>
> Heya Folks...
>
> I have had a need to program a bunch of EPROMs lately (27128 varieties) and
> Im not sure if there are sunspots or something, but I can't seem to program
> anything on either my 29B OR my Intronics USB Programmer... I have
> successfully programmed like 4 EPROMs out of like 40 attempts. My EPROM's
> are old pulls from either Atari boards or other used ones I have acquired
> over the years in storage sticks.
>
> They are either
>
> ST 27128A
> Fujitsu 27128
> SEEQ 27128
> TI TMS27C128
>
> Im being fairly careful about the programming voltages and the 29B
> identifies the IC before programming it.
>
> On the 29B I just get an Error #22 Programming Error right away.
>
> Sorta the same thing on my Intronics.... Set it up, verify blank, program,
> error right away.
>
> Are these just too old? Anyone have any good tricks?  The strange part is
> that I was having this exact same issue last night, then all of a sudden my
> 29B programmed 3 in a row just fine... today, nothing.
>
> Thanks
> Jess
>
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