Bill,

isn't AppleTalk since the very first beginning at 230.400 bps? I think
even a MacPlus ser port supported that speed. OTOH, as far as I know
the ser port speed went down, if running at the same time networking
and ser port connecting activities.

There are some programs (like ProTERM, FreePPP), allowing you to set
the port speed higher than 57.6 and it seems to work - sometimes.

May I ask a somewhat related, but not NetBSD question (since you're a
serial connection guru here :)) ): Would it be better to use a
IIfx/Quadra 900/950 with the built in serial I/O controller on or off.
In case of OFF FreePPP allows 230.400 bps (in case of ON only 57.600
are accepted, possibly because the controller tells FreePPP so).
Practically, with a LASAT 56K V90 modem attached, performance - to me,
but it's only an impression - seemed better with the Serial Switcher
set to ON and consequently port speed set to only 57.600.

Thanks in advance & kind regards,

Ulrich Hausmann


On 23:08 Uhr +0200 20.04.1999, Bill Studenmund wrote:

> Why did "tech@openbsd.org" show up as the "to" address in a message to
> port-mac68k?
>
> I'm going to assume you're running NetBSD, not OpenBSD, as that's
>what I'm
> familiar with.
>
> On Mon, 19 Apr 1999, Grant Stockly wrote:
>
> > I'm interested in using the Mac IIci's serial port at 128,000bps.
>
> You can try, but I doubt you'll be happy with the results. There's a
> reason why MacOS doesn't support this baud rate on '030 class hardware.
>
> > I hear this is possible by supplying an external clock (there is a
>little
> > box where I can enter in the frequency [in the booter]).
> >
> > Does anyone have any information on how I'd go about using the
>serial port
> > at this speed?  What type of clock to give the serial port?
>
> You need to give a clock signal at 2.048 MHz. While a clock at 128 kHz
> would work, that clock would have to be synchronized with your
>datastream,
> which would be a pain.
>
> The clock needs to be a valid RS-422 signal - +/- 5V should be fine.
>
> > If you could, please send me any info.
> >
> > HSKi and GPi are valid clock inputs?
>
> Yes.
>
> Though to be honest, I think you'll be very unhappy with the results.
> It'll work fine for transmitting data, but you stand a GREAT chance of
> having overruns on receive. Or the machine will be unusable while
> receiving.
>
> What exactly are you wanting to do?
>
> Take care,
>
> Bill