Mac G3 Beige (Tommy Trussell)

Tommy Trussell tommy.trussell at
Wed Dec 20 22:16:05 UTC 2006

On 12/20/06, Frarquit <frarquit at> wrote:
> > To activate the serial ports in an Old World Mac (or presumably a New
> > World Mac with a third-party serial card), add
> >
> > pmac_zilog
> >
> > to your /etc/modules file. (If you're compiling your kernel you could
> > just compile it in.)
> So, solved the problem number 2, we go back to 1:
> How can I configure the pmac_zilog module to print?

OK here is a guess (I have not tried it, though my BJC4550 is a serial
and parallel printer so I could try to dig up a Mac serial printer

1) Examine your dmesg output to determine which port gets assigned to
which /dev -- on mine the serial/printer port gets assigned to
/dev/ttyS0  (that last character is a zero).

2) Assuming you're using CUPS, configure it using your favorite
method, such as the web interface (which in U/K/Xubuntu you have to go
through some rigamarole to activate). Personally I really like the
printing config tool in KDE. (You can install the Kubuntu stuff and
run any of it in Xubuntu, or switch to KDE at will.)

2a) When CUPS asks how the printer is connected, I BELIEVE you put in
the port like this-- serial:///dev/ttyS0/  -- but I don't know for
sure, having never tried it.

2b) If you are very very lucky, the model printer you have will be
fully supported by a CUPS driver -- simply choose it from the list. If
you aren't so lucky, you might try the commercial software called
TurboPrint, which works MUCH better with my Canon printer than any of
the CUPS drivers.

CAVEATS -- having set up more than my fair share of serial printers in
a previous life, I can tell you that you very likely will have port
speed, buffer overruns (handshaking problems), or cabling issues.

SPEED: If the printer doesn't work at all, you should determine the
speed of the printer's interface, and set the Mac's serial interface
to match. (This includes the parity and number of stop bits. Make them
the same.) Alternatively, set the printer's serial interface to match
(with its dip switches or software settings). Whichever is easier.
(Since minicom knows how to configure the serial ports, I presume the
standard unix serial utilities work with the pmac_zilog driver, but I
have not delved into it. Installing minicom might help you debug the
printer settings, or it might be a real time sink, because most
printers don't have a lot of things to "say" to you over their serial

HANDSHAKING: If the printer seems to work on very short documents but
goes crazy when you print several pages at a time, you're probably
having a handshaking issue between the computer and the printer. Set
both to use the same form of handshaking -- hardware handshaking is
best, XON/XOFF handshaking might work, might not (it works best on
very slow connections). Hardware handshaking depends on your cabling,
and it's been a long time since I've done it so I don't remember the
acronyms for sure.

CABLING: If you are using some sort of adapter cable instead of the
standard Macintosh serial cable, be prepared to get heavily into the
arcane world of RS-232 handshake lines, and how they connect to the
RS-422 serial ports on a Macintosh.

I hope this gets you going... if it doesn't, please say what kind of
printer you're using so someone can guess a little better.

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