Flow control with HST

[Brett Behm]

In article <2233 at ucqais.uc.edu>, pmartin at ucqais.uc.edu (Paul Martin) writes:
> 
> I setup my Xenix/386 system with an HST 9600 bps modem, with the modem
> locked at 9600.  The problem is that the rts/cts flow control doesn't
> seem to work under Xenix although it works fine under DOS.  I am using
> the modem device /dev/tty1A so I figured that it would flow control
> correctly.  I could setup the modem to use xon/xoff to handshake but
> I don't think that zmodem would like that very much.  

I've read many articles discussing flow control with modem use.  The 
problem arises in what application is going to do the transfer.  Under
cu() it is possible to do flow control by modifying the gettydefs file, 
but with UUCP transfers you are under the mercy of uucico() which
does a ioctl() turning off all forms of flow control.  Below is an 
example of a stty -a < tty1A (our modem port) during a UUCP transfer
running on Xenix 2.3.2:

speed 9600 baud; line = 0; intr = DEL; quit = ^\; erase = ^H; kill = ^U; eof = ^F; eol = ^A; swtch = ^@
-parenb -parodd cs8 -cstopb hupcl cread -clocal -loblk -ctsflow -rtsflow 
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl -iuclc 
-ixon -ixany -ixoff 
-isig -icanon min = 6 time = 1 -xcase -echo -echoe -echok -echonl -noflsh 
-opost -olcuc -onlcr -ocrnl -onocr -onlret -ofill -ofdel cr0 nl0 tab0 bs0 vt0 ff0 

It is up to your port to keep up with the transfer rate or the UUCP protocol
to correct any errors.  Then again if you have the UUCP source, you can
always modify the ioctl().

Brett Behm     Zenith Data Systems