23 Apr
2016
23 Apr
'16
7:26 a.m.
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.
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.