Maybe we need a list of recommended serial port add-on cards although the
thrust of other's arguments is to simply buy a good USB->serial adapter.
I just bought a little VIA box with serial ports which I hope will act as
a nice way to connect to the consolves my ALIX boxes which will arrive in
the next week or so.
I have not worked on serial port drivers for nearly 20 years and I only
ever worked on SGI, MIPS, SUN and BSDI kernels. When I worked on really
good hardware implementations of serial ports, the work was extremely
satisfying. And the reverse was also too true.
And for fear of starting a war, I will say nothing about the 'tty' driver.
So take this with a grain of salt.
On Fri, 3 Mar 2017, Stuart Henderson wrote:
I think I've sometimes seen similar hangs when the card wanted
something from the handshake lines that wasn't being provided.
If it's not plugged in yet (with a null modem adapter if needed,
note not just a gender-changer) then plugging it in might make
it come to life.
If this is required, something is poorly implemented with either the
hardware or the driver.
Mind you, we are often stuck with hardware so this is often the only
workaround.
What I tend to do for consoles on PCs is use a DE9-RJ45 adapter, and in
that adapter I loop back DTR-DSR and CTS-RTS (so as soon as the computer
raises DTR it sees DSR) and just connect GND/RXD/TXD between the
machines which avoids a few headaches..
Is this still needed. It is probably tolerable in this day and age where
ports can do over 100kBaud. But still a bit rough.
One would think that by now, serial port technology would be perfect. But
sadly no, if only because the demand no longer exists to support a vibrant
mix of products. Some of the older Motorola (and TI, Cosystems, and ...)
serial port cards were sheer works of art, and especially the ones with
CPU offload features.
Regards - Damian
Pacific Engineering Systems International, 277-279 Broadway, Glebe NSW 2037
Ph:+61-2-8571-0847 .. Fx:+61-2-9692-9623 | unsolicited email not wanted here
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