Recommendations for a serial port card you can actually BUY?

[Matthias Andree]

Karl Denninger <karl at denninger.net> writes:

> Much of the latter hardware is still only available in a serial interface,
> no matter the cost.  It is not high-data-rate by any means (typically 4800
> or 9600 bps) but it is what it is.

Personally, I've seen lots of 14k4 fax stuff deployed, but then again,
doesn't matter much.

Anyways, in that previous life when I bought my hardware (for FreeBSD
4.X that was), there have been FourPort-compatible cards (not original
AST, but third-party with the same register layout and functionality,
including interrupt vector registers that FreeBSD 4.x couldn't use, but
Linux) -- I got the ISA variant, there have also been PCI specimen but
haven't tried them.  I'm not sure how I would configure the PCI stuff
for FreeBSD though, I've only ever used ISA and the instructions the
vendor (VSCom) shipped were for Linux's setserial(8)...

> Serial over IP will not work for either.  Serial-via-USB might, and I will
> look into that, but I suspect I'm going to get in trouble with that one,
> especially if I have to toggle control signals (e.g. DTR, etc) or support
> hardware flow control (and for the fax servers, you DO need it if you expect
> things to work correctly.)

I'd be less concerned about those than about issues with getting things
to work in real-time, or perhaps USB hub quality...

USB isn't meant for that type of real-time thing, but for commodity.  It
doesn't matter if your keypress arrives a ms sooner or later, but it
does matter for your serial bytes. Buying several different
USB-to-RS232-converters isn't an issue financially anyways if you're
ready to spend 500 dollars - these cost perhaps 10 a piece. Only you're
often not sure you're getting the same hardware next time you order the
same article number, because this stuff is often made in Indonesia or
China or some place like that and brands seem to do some kind of
"manufacturer hopping" there, and it's not sure that the manuf' sticks
to the specs... ask Techsolo about USB 2.0 hubs.

> its hands when you plug it in.  I wasn't aware that the USB to Serial
> converters would work - I can try them, but there are a lot of those out
> there that don't work right even under Windows - expecting them to under
> FreeBSD might be asking too much.

It's a matter of trying them -- there are examples of cheapo hardware
where FreeBSD seems to work better. Not that it helps your issue, but
the Windows 2000 drivers (all versions I could find, RATech and Edimax)
for RATech 2500 WLAN chips for instance is plain growse and next to
unusable; the Linux driver is flakey, the FreeBSD 6.1 driver however is
rock solid (but unusable, among other IEEE 802.11 stuff, under 6.0...)

-- 
Matthias Andree