Subject: Re: CG6 and serial port support questions
To: Johnathan Vail <>
From: David Gilbert <>
List: port-sun3
Date: 03/05/1996 10:35:44
>>>>> "Johnathan" == Johnathan Vail <> writes:

Johnathan>    2) The serial ports have a top speed of 19200 baud.  My
Johnathan> understanding was that the hardware in the 3/60's could
Johnathan> support 38400, but it was a function of SunOS that limited
Johnathan> the port to 19200.  (I recall you could set the serial port

	Speaking at the owner of a Sun4/260 (which, I belive, uses the
same chip), Sun's chips do support 38.4, but I'm beginning to believe
that it would be difficult to have an operating system support the
chip running at 38.4.  My Sparc has trouble keeping up at 19200 (with
a 14.4 modem attached) with ppp.  With uucico, it gets even a little
bit worse.

	The problem is that the chips have a 3 byte FIFO.  Those three
bytes are easily exhausted.  Moreover, when I'm full bore receiving
with ppp, the system is hit hard --- close to unusable.

	While I can't 'know' yet --- I don't have a Sun3 to play with
yet, I suspect that 19200 is good fishing for a Sun3.


|David Gilbert, PCI, Richmond Hill, Ontario.  | Two things can only be     |
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