NVRAM replacement for sun systems

Heyo,

This post is a slight tangent to OpenBSD fwiw, but I think relevant 
since a lot of users of older ultrasparc 64 gear is impacted by a dead 
NVRAM/IDPROM battery in their legacy systems.

I designed an NVRAM (IDPROM) replacement for older sun systems. I was 
using my old sunblade 100 fairly regularly with OpenBSD until the 
battery in the rtc nvram chip died (apparently when OpenBSD 6.3 was 
still a thing since that CD was in the drive of the machine I got 
started this evening).

Since Sun used the non-battery replaceable variant of the obsolete 
STMicroelectronics M48T59Y clock chip, it meant that repairing it 
requires going to ebay and finding a new part, hopefully where the small 
lithium power source is still good, or getting out the Dremel and 
cutting out the old battery and soldering in a new one.

(not ideal either way).

Anyway, I tried my hand at putting together a replacement using a 
different model IC with a REPLACEABLE BATTERY and have had some success 
on my own machine (SunBlade 100). Where I'm able to get it to post and 
remember it's serial number and mac address across power cycles now.

https://i.imgur.com/edVAuLH.jpeg

Image shows my venerable SunBlade 100 running for the first time in 
3(ish) years with the new battery backed nvram thing!  Pretty happy so far.

Also btw, I notice that openbsd 7.0 installer boot, but this has been 
reported already on the mailing list. I can confirm i'm seeing the exact 
same behavior as in the following post

https://marc.info/?l=openbsd-sparc&m=163474865808693&w=2

The computer runs fine with the older 6.3 though, so i'm not sure what 
has changed since the machine last ran properly but it currently isn't 
working (I haven't tested -current yet).

-- 
Ted Bullock <[email protected]>