Re: Re[2]: [9fans] Anyone awake?

[Jack Johnson <fragment@nas.com>]

On Sun, 2003-07-27 at 09:43, jmk@plan9.bell-labs.com wrote:
> I'm a bit confused here. Is the DIN8 out of the Mac serial or
> parallel signalling? If it's serial then all you need (as has been
> pointed out), is a DB25 to DB9 converter, they cost practically
> nothing and we have boxes of them. There was a time when PCs came
> with one serial port DB9 and the other DB25.

It should be serial.

On ancient Macs, there was some minor hardware difference that would
only allow LocalTalk over the "Printer" port, but that difference
evaporated ages ago (though it wasn't an option to switch to the other
port until OpenTransport came along).

I just realized I know way more about that than I care to.

Anyway, in the pre-USB Mac days you'd find that if you wanted an
external modem, it would cost you another $20 over an external PC modem,
and the only difference was the enclosed software and the cable.  A PC
modem and a random DIN8->DB25 cable would do the trick just as well.

And, as mentioned before, similar scenarios with DB25 null-modem
adapters or dumb terminals that support it will work just fine doing Mac
<-> whatever serial data.  If you have a used computer store in town (or
work for an organization with a decent basement), you can usually find a
dumb terminal pretty cheap, and I find it's easier to just keep one in
the garage in case of emergency rather than deal with hunting down
cables, a spare machine for serial configuration/debugging, etc.

-Jack