AlphaStation 200 NVRAM Problem

[ethan at 757.org]

> I posted a while back about this problem.
> I am wondering if I have a chance of reviving this system or if it is beyond
> repair (by me)? I can't get anything out of the console port, and I don't
> know if I should expect to be able to get output from there or not. If I
> know that I should expect output on the serial port despite an NVRAM
> self-test failure then I could investigate that further with my breakout box
> (don't have a protocol analyser).
> I have been unable to identify the NVRAM chips either.
> Thanks for any help.
> Regards
> Rob

I'm not familiar with that particular system, but there are similar issues 
in the arcade game world (and I guess to a lesser degree Sun 
Sparcstation.)

Someone mentioned there is a battery. It could be held by that, or a 
module from ST Microelectronics or Dallas Semiconductor. The latter two 
tend to be plastic packages that are ~28 pins or so and taller than normal 
chips. The Dallas and ST modules have RAM/real time clock and 
a battery in one package.

In the case of some arcade games (Silent Scope from Konami is a big one), 
once the NVRAM looses it's contents the machine wont load past it in the
bootup process. On the Sun Workstations when the modules go bad it will 
boot but but the MAC address is blank. It's possible to reprogram the 
contents back on the Sun workstations.

If the case of the AlphaStation is that it can't get past post without the 
contents of the NVRAM, and the NVRAM is in a Dallas or STM module then the 
easy solution is to get a dump of a working system, perhaps hex edit the 
contents to correct the MAC address, then plug it in (hopefully socketed.)

If the NVRam is held by a CR3202 battery and a SMD SRAM chip or something, 
there would have to be a way around it being blank I'd imagine.



--
Ethan O'Toole