[rescue] Tatung Compstation NVRAM question

[Steve Hatle]

So…

I pulled the NVRAM with a Glitchworks board out of my Sparc 4.

Put it in the Tatung, and it comes up with good hostid and MAC, but 
IDPROM contents invalid. I reset the machine ID from 80 to 72, 
recalculated the checksum and reset.

Everything came up fine, and it survived poweroff/reboot.

I put the Tatung NVRAM in the 4, and same thing - everything OK after I 
reset the machine ID and recalculated the checksum.

I then put the NVRAM back from the 4 into the Tatung (which is where it 
started with the problems) changed the machine ID again, and it’s all 
good!

Put the NVRAM back in the Sparc 4, reset the machine ID, and it’s also 
good.

I can only speculate on why this may be happening, but I’m not going to 
press my luck. I’ll just confirm thing are still good tomorrow, and if 
they are I will happily mark this episode as closed!

Steve




------ Original Message ------
>From "Steve Hatle" <steve.hatle at gmail.com>
To "Walter Belgers" <walter+rescue at belgers.com>
Date 7/19/2026 12:31:59 PM
Subject Re[2]: [rescue] Tatung Compstation NVRAM question

>Like you, I feel like I’ve done this a million times 🙂
>
>I’ve recalculated the checksum, tried different machine ids, used 
>different MAC address values…
>
>I’m not sure how to interpret the output from the the
>
>.idprom
>
>Command in openboot; I will need to read up on that. It seems like 
>there’s some part of the data that’s not being written correctly to the 
>chip so the checksum is calculated from “bad” values. I don’t know if 
>there’s a way to write over all the memory space in the chip and start 
>over.
>
>My next step will likely be to get out the Dremel and put a battery 
>board on the chip that actually came out of the Tatung.
>
>Steve
>
>
>------ Original Message ------
>From "Walter Belgers" <walter+rescue at belgers.com>
>To "The Rescue List" <rescue at sunhelp.org>
>Cc "Steve Hatle" <steve.hatle at gmail.com>
>Date 7/18/2026 5:34:14 PM
>Subject Re: [rescue] Tatung Compstation NVRAM question
>
>>>On 18 Jul 2026, at 23:55, Steve Hatle via rescue <rescue at sunhelp.org> 
>>>wrote:
>>>I put in a chip with the Glitchworks battery fix board and updated 
>>>using the mkp method.
>>>[..]But - if I power down and unplug things for a couple minutes, 
>>>when the machine comes back up it has the error
>>>Incorrect configuration checksum
>>>[..] When the banner prints, the values for hostid and the MAC 
>>>address are there from what I programmed, but then there is the
>>
>>That sounds like the values are retained (MAC and hostid are still 
>>there - so battery is working) but the checksum is incorrect.
>>That's programmed with the 0 f 0 do i idprom@ xor loop f mkp command 
>>(I just programmed 50+ of these so I know this by heart now ;-)
>>Maybe you can just retry that single command to see if that fixes the 
>>checksum.
>>
>>Regards,
>>Walter.
>>
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