Lousy performance with 6386 tty port and Simultask

Bill Mayhew wtm at uhura.neoucom.EDU
Mon May 28 14:27:42 AEST 1990


Yes indeed.  This is a problem.  Under some cirucmstances,
Simultask can't even keep up with a 2400 baud data stream on the
Simlultask COM port.

The way to get some relief is to obtain the public domian "fas"
(short for 'final asynchronous solution') tty driver.  Fas may be
linked into the kernel in place of the standard "asy" driver.  Fas
requires the use of a 16455 UART chip in place of the stock 16450
or 8250B.  If one didn't want to alter the harware of a 6386,
she/he could add a generic COM board and replace the UART on that
generic board.

The fas archive comes with all the files one needs.  While the
Readme file doesn't mention AT&T Sys V specifically, follow the
instrucitons for Interactive's Unix, the procedure is the same.
The only thing I would recommend is changing the the fas driver
major device number to 19 (decimal) from the value of 4 that is
mentioned in the documentation.  If you install everything
available in the AT&T kernel, all the major numbers up to 18 are
already spoken for.

I am very pleased with the utility of the fas driver.  Fas did the
trick for me.  I needed fas to get full benefit from  my
Trailblazer Plus.  With fas, I can run the tty port at 19200, which
results in ~1400 char/sec transfers of large (~100K) files with
modem compression switched off.  I am using a generic 33 MHz ISA
bus system I built a la carte myself and AT&T Sys V 3.2.1.

==Bill==
-- 

Bill Mayhew  Northeastern Ohio Universities College of Medicine
Rootstown, OH  44272-9995  USA    216-325-2511
wtm at uhura.neoucom.edu   ....!uunet!aablue!neoucom!wtm



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