Hi,

> This is what I'm interested in doing.
> The 4/600 only has the one data port though.
> If I can speak serial instead of LocalTalk over this port, without an adapter, that would be perfect.
> I didn't think this would be possible, but as I've mentioned, this isn't my area of expertise.

Yes, this does get a little confusing.

Here are some things you can try:
Find the documentation for your printer and see if it will allow non-Mac
printers to connect to it via an RS-232 to Apple serial cable. If so, you
should be able to initialise the port in NetBSD by updating /etc/ttys, and
you may see something (flashing light, maybe even a page) by just catting
a PostScript file to that serial port.

Note that most direct computer to printer connections are capable of both
serial and LocalTalk, but I'm not sure if the printer will listen to
serial if a LocalTalk connection is sensed. You may need to make your own
cable which looks to the printer like a regular serial connection. This
involves converting the connection from balanced RS-422 to single ended
RS-232 by letting TxD+ float and tying RxD+ to ground on both sides.

So if you can't just send serial data from NetBSD, and you don't want to
make a cable, you can get an Ethernet to LocalTalk bridge (they work very
well; I'm using one), or you can get something like an LC (II, III) or
Quadra 605 as they are small and take very little power, and install the
free LocalTalk LaserWriter Bridge software from Apple.

How's that?

John Klos
Sixgirls Computing Labs