---- On Fri, 14 Dec 2001, Allison
(ajp166(a)bellatlantic.net) wrote:
8251 was an OK chip, it had bugs, FYI
there are
three versions
and each has it's oddities! I have tons
of
them and use them
but, you do have to be aware of the
oddities.
The worst ones
are initial programming after reset
(buffer
clear bug) and the
repeats last character on /cts false if TX
shifter is not empty
(8251A). However the 2SIO didn't use it.
NS* did use them as did many others. The
worst chip was
the 8250.
Allison
IIRC the Intel 8251 did full Sync as well as
Async which was a plus. It's annoying
drawback -- (DEC used it in the Robin and
Rainbow) was the lack of modem flow control
support.
I'd have killed for an 8251 with
CTS/RTS/DSR/DTR and DCD all on chip.
Perhaps it should've been done on two chips
if Intel couldn't get it on one.
Bill