> Information on using that is however scarce and scattered, you can find > some here to start: <http://labs.hoffmanlabs.com/node/1286> and then the > pinout for the serial diagnostic port is included here: > <http://manx.classiccmp.org/collections/mds- > 199909/cd1/alpha/pcdsatia.pdf> > (the boot sequence is also described here, so you'll know that an NVRAM > failure is reported by DROM code, i.e. before the final SRM or ARC console > takes over and is able to use the regular serial port).
Indeed, I don't get any output on the standard serial port. > > That's a bit cryptic, but knowing that this is a low-level CPU interface you can > gather the wiring from this document: > <http://h18000.www1.hp.com/cpq- > alphaserver/technology/literature/164lxtrm.pdf>. > So BSROMCLK is Tx and SROMCDAT is Rx, but as noted here and in the > discussion in the first reference you need an EIA/TIA 232 driver and receiver > (there is power available on the diagnostic port, so you can use it for the > circuit), and of course you need to cross the lines wiring them to your host. > I don't think the SROM diagnostics are going to help much because the failure is in the DROM sequence, which comes after the SROM. > Finally the SROM console command reference is here: > <http://h18000.www1.hp.com/cpq- > alphaserver/technology/literature/srommini.pdf>. > This manual doesn't specifically cover the Avanti, but I'd expect the user > interface to be similar -- it's a low-level tool close to the CPU after all. > > NB on Avanti the 8kB NVRAM is separate from the TOY/NVR chip (which is a > Benchmarq BQ4285, providing 114B of general storage only). > I had already located the Benchmarq chip and found the spec to be insufficient for the 8K NVRAM. The problem is, I don't know which chip has the NVRAM, I have not been able to locate it and the manuals don't tell me. I hope it isn't one of the ASICs. I have posted a photo of the board here: http://bit.ly/1qHQnaB in case anyone can id the NVRAM. If the NVRAM contents are maintained by the battery then there should be a way to reset the NVRAM contents, but there does not seem to be a way. I wonder if the NVRAM persists without power? The manual seems to say that the TOY is battery backed, but makes no mention of the NVRAM needing the battery. Regards Rob
