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[lawson_whitney at juno.com]

On Wed, 5 Dec 2001, T REX wrote:

> Hmm well it is a posibilty, the weird thing here is that the Thinkboxx
> does not use hardware flow controll, this i know since the serial cabel
> suplied only has three pins where two are data and one is ground.

It is basically impossible for linux to transfer data over such a cable
if hardware flow control (CRTSCTS) is enabled.  A write may succeed, but
no data will go out the serial line until CTS comes up, and with only 3
wires, there is none for it to come up on.

> I think that the lacking support may be conusing the error, but why does it
> work under windows when hardware flow controll is not available.
> The program must be relaying on software flow controll,
> does windows use software flow controll that emulates DTS/DTR signals.

Seems I saw in a trace it asks for hardware flow control.  Unless there
are 2 different comm devices in this piece, here it was:

| 0806d898:Call kernel32.SetCommState(00000060,406150ac) ret=0043e017
| trace:comm:SetCommState handle 96, ptr 0x406150ac
| trace:comm:SetCommState bytesize 8 baudrate 9600 fParity 0 Parity 0
| stopbits 1
| trace:comm:SetCommState ~IXON ~IXOFF
| trace:comm:SetCommState CRTSCTS
| warn:comm:SetCommState DSR/DTR flow control not supported
| 0806d898:Ret  kernel32.SetCommState() retval=00000001 ret=0043e017

| 'flow control not supported'. This could be the reason.
| I have no idea why it's not supported - I suspect a system-related
| reason, if  there is no api available to managed this stuff in the
| Linux Api, for example.

| Gerard
_______________________________________________
| /gp/pine/wine-users byte 430933/509199 84%

Flow control as practiced by linux (CRTSCTS) is supported and works.
We don't know what DSR/DTR is 'spoze to do, so it isn't.  Most windose
apps seem to ask for both, as this one does, even though the cable makes
it impossible for either of them to work.  Maybe hardware flow control
is a stub in windose?
>
> The fact that it is the lacking 1024 bytes that couses the problem strongly
> supports the teory that the problem resides in the serial communication.
> Maybe that when the thinkboxx sends an request, this request for some reason
> does not rach the comm port or that the answer dont, maybe i hawe a wronlgly
> configured flow controll.
>
I think it is lacking 1024 bytes coming back because CTS never comes up,
so nothing that was written to the port goes out the line.
I think if you will use a real serial cable, it will work (check if it
is a null-modem cable.  If pins 2 and 3 are flipped on the 3 wire, it
is, and you need to flip some of the control signals too.  I have a
little null-modem-cable micro howto I can send you if you need one.)

Either that, or if you can configure the app to not ask for hardware
flow control, especially not CRTSCTS ( RTS/CTS, CRTSCTS is the name of
that bit in the termios structure on linux) if it will try to use a 3
wire cable.

> On windows the program does not hang ewen when nothing is connected to the
> comm port so it cant be getting the 1024 bytes there either but it dosnt
> hang,
> maybe windows suplyes the program with the 1024 bytes.
>
> Wow this was a lot of sh..., i just poured out my thoughts here.
> So, does anyone know anything, this program is important to me, so i would
> be greatful for any help.
>
> The1trex


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