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From: tac@sei.cmu.edu (Timothy Coddington)
Newsgroups: sci.electronics
Subject: I Can't copy an EPROM... Help!
Keywords: EPROMS
Message-ID: <7023@aw.sei.cmu.edu>
Date: 15 Sep 88 22:05:56 GMT
Sender: netnews@sei.cmu.edu
Lines: 44

I'm trying to copy a set of debug ROMs (Part # Motorola 133ABUG) and I've
had no success.  Is there something I've missed?

The ROMs are for a single board computer (Motorola MVME133A-20).  This is 
how I judge success/failure: if I remove the ROMs, copy them, install the copied
version in the board and it doesn't go into halt state and I get the debugger
prompt, then I've succeeded.  Otherwise, something went wrong.

The originals have the following part number: Fairchild MBM27C512-20

I've tried copying to both of the following parts without success:

		Toshiba TMM27512D-20
		and
		NEC D27C512D-15        both pgm @12.5V

I'm using the following programmer:  Data I/O 201.  I know the Toshiba part
has been successfully programmed with downloaded data before.  This is the
first time I've tried to do anything with the NEC part on this programmer.

Yes I do have permission to copy these chips!!

When the data is "L"oaded off the original I get a checksum.  After I've
"P"rogrammed the blank (which I've checked to make sure is blanked) I get
the same checksum result.

Since the exact device setups are not available in the programmer for any
of the above parts I've tried the only two *512 device setups available.
Data I/O didn't promise anything when I called them, but they did say which
one should work (remember the toshiba part has been programmed before).

Is there something I've missed.  It seems like the copy goes OK, but the
board doesn't boot!  Is there something about the way some ROMs are
programmed that prevents them from being copied?  Has someone run into this
problems before?  suggestions?

HELP!!
    HELP!!

    Tim Coddington  Software Engineering Institute, Carnegie-Mellon Univ.

    Arpa: tac@sei.cmu.edu     412-268-7712  (h) 244-8557

    Thanks for taking the time!