[time-nuts] Solartron 7081 ROMs

Chris Stake stake at btinternet.com
Wed Apr 29 20:10:08 UTC 2009

Yes, Low supply voltage and slow access time might succeed with those old
Best of luck
Chris Stake

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Peter Vince
Sent: 29 April 2009 20:50
To: brooke at pacific.net; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Solartron 7081 ROMs

I'm sure there was a message on this group a month or two ago, where the
line was to read the EPROMs with a slightly lower than usual voltage.

Peter Vince

On Tue Apr 28 15:40 , Brooke Clarke <brooke at pacific.net> sent:

>Hi Dave:
>I've read that there are some tricks to coaxing the data from memory 
>chips related to reading them under different conditions.
>It's a lot of work, but it's possible to disassemble the code.  That 
>would allow it to be repaired.
>Have Fun,
>Brooke Clarke
>David C. Partridge wrote:
>> This is a call to anyone who has a Solartron 7081 and has saved a copy of
>> their ROMs (if you haven't you may end up in the same boat as I am - the
>> that's up the creek without a paddle).
>> One of the ROMs on my earthy processor board has died.
>> It would appear that the ROMs in this 7081 were updated to a high level
>> firmware at some stage in its life as the total ROM image size is greater
>> than that of a set that was copied by Bill Ezell from his 7081 even
>> his meter has a higher serial number (461) than mine (180).
>> The ICs in question and the CRC16 checksums (in hex) for my ROM set are:
>>  IC430	3238
>>  IC415	C5C0
>>  IC414	1260 
>>  IC413	B958
>>  IC412	ED50
>> If you have saved your firmware ROM images, and the checksums for your
>> match these, I would be immensely grateful if you could send me the image
>> for IC414 (the middle one of the three).
>> If as a result of reading this message you feel impelled to save your ROM
>> images and find your checksums match these ... 
>> Obviously if I can't find a good image of that ROM, I'll just install the
>> older firmware, but one never knows.
>> Cheers,
>> David Partridge

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