as long as we're doing hardware design on the nanog list again, i'd like to
mention that there's a little device that sits on an ISA bus and has an
onboard PCIC (PCMCIA bus controller). to this one attaches a pair of
50-pin ribbon cables, and to these one attaches a device that fits
physically where a 3.5-inch floppy drive would fit (which means you
generally need a 5.25-inch expansion mount, cost:$3.00). the whole thing
costs about $150.
if your UNIX-like system that runs on an ISA bus also would run on a laptop
and knows how to support PCMCIA devices, it will see these slots as
completely normal. and if you put an NCR WaveLAN into one, you have
yourself an ether/wireless router. and if you put a 20MB ATA Flash card
into it, it looks like a (slow) file system. and if your ROM knows how to
boot from ATA (as it might if it can boot from an ATA CDROM), presto: BSD
router, no moving parts.
naturally you need to edit the hell out of /etc/rc to make it build a big
ramdisk, populate it from the Flash's binary tarball, and chroot to it
before starting gated. the chroot'd /etc/gated.conf should be a symlink to
a small config file system on a second ATA Flash. "/", even though a RAM
disk, is mounted read-only. system upgrades are done by powering off the
unit, replacing "drive 0" with an updated 20MB Flash card, and powering it
caveats: 20MB isn't very large for a BSD system, even with shlibs -- you
have to be highly selective about what you take; also, for /var/log it is
probably a good idea to include a rotating magnetic media, unless you're
going to use syslog's "remote log server" mode, which since it's UDP is not
reliable enough for some forms of auditing that i've needed to design for.
hope this helps.