From: wong@cs.tu-berlin.de (Wolfgang Jung) Subject: Re: 16550 uarts and .99pl8 Date: 26 Apr 1993 11:27:05 GMT
Carl Fongheiser (cmf@ositos.UUCP) wrote:
: In article <C5yv07.Eny@world.std.com> nigel%gamble@uunet.UU.NET writes:
: >I don't have any problems with 0.99pl8 and my 16550A. But I recently
: >read over in comp.sys.ibm.pc.hardware that the difference between a
: >16550 and a 16550A is that the 16550 has a bug in the FIFO which can
: >cause repeated characters. So the question is: has anyone who knows
: >that they have a 16550A (and not a plain 16550) seen this repeated
: >character problem?
: The Linux serial driver doesn't turn on the FIFO for 16550's, only the
: 16550A's. National Semiconductor came up with an algorithm to reliably
: distinguish between the two. I doubt many people have honest-to-goodness
: 16550's, anyway. They didn't last very long (due to the FIFO bug).
: In any case, the Boca cards use a chip which is essentially 4 16550A's in
: one chip. My Boca card was running with absolutely no problems under
: 0.99pl{4,5,6}; the problem only started cropping up with pl7.
I just installed a 16550A Card in my Box, and testet the whole thing,
And I did not get multiple Characters.
Gruss
Wolfgang