S4 COMPARE command

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bender
Posts: 1
Joined: 23 Mar 2014 00:36

S4 COMPARE command

Postby bender » 23 Mar 2014 00:54

I am using a Dataman S4 with S4WinDriver version 2.17 and trying to repair and old device that uses Intel 2716 PROMs. What would be some of the reasons that the COMPARE command does NOT match all data in the PROM with the contents of the USER-RAM between the START and END addresses? Each time I run the command COMPARE and do not get the status message SAME, the data bits that do not COMPARE are usually at different addresses. Most of the 2716 PROMs COMPARE correctly but some do not. Can somehow this be corrected? Is it caused by a PROM that somehow became faulty? Dirty pins on the PROM? There are not to many things that can go wrong and I am running out of ideas. I would appreciate your help.

Dataman (Neil Parker)
Posts: 931
Joined: 10 Nov 2011 09:51

Re: S4 COMPARE command

Postby Dataman (Neil Parker) » 27 Mar 2014 14:24

Hello Bender,

There are a few reasons why a compare might fail. However you have listed most of them. Poor contact as a result of contamination or oxidation on the leads of the device/ZIF socket. This will usually be apparent through running the checksum operation repeatedly, if the checksum value changes each time then there is a contact problem somewhere.

EPROM devices can become corrupt over time with the odd bit here and there changing state causing the COMP to fail.

The only way to correct a corrupted EPROM is to erase it with a UV eraser and reprogram it with the correct data.

Best regards,

Neil Parker
Dataman Programmers


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