>> Does anyone know where I can find any information/documentation for the
>> kernel's boot sequence?  Information on the PROM functions would be very
>> helpful.  Thanks.
>
> About the best doco we have is in /sys/arch/pmax/stand and
> /sys/arch/pmax/include/dec_*.

The most comprehensive description of REX 'ROM Executive' can be found as;

    TURBOchannel Firmware Specification, EK-TCAAD-FS

	ftp://ftp.netbsd.org/pub/NetBSD/misc/dec-docs/ek-tcaad-fs.ps.gz

The document is mainly targeted for TURBOchannel option card designer,
however, this is so valuable because it describes 'how TURBOchannel
computer should be built' in fact, and is very useful to learn
DECstation >> prompt and REX callbacks in detail, too.

I'm day-dreaming to have 100Mbps TC NIC, or even RM5xxx based 50MHz
TURBOchannel MIPS box yet fully compatible with abandoned
DECstation :->.

Tohru Nishimura
Nara Institute of Science and Technology