topix@gpu.utcs.utoronto.ca (R. Munroe) (05/25/91)
I'm having a bit of strange trouble with a Hayes Ultra 9600 Smartmodem hooked up to a PI 25. I can dial out O.K. I also have no trouble dialing in - the modem connects, I get my login prompt, etc. The trouble starts when I issue a command who's output is more than 5 or 6 lines. For example, if I issue an 'ls' command, the first 4 lines of my directory listing print out fine. The next line is completely garbled and the following lines don't print. If I enter a carriage return, my prompt appears as normal, and I can continue along happily - until I issue another command that prints more than four (or so) lines to my screen (the problem may actually start after a certain number of characters have been printed - it just seems four lines of output is the average). I've tried the modem on /dev/ttym2 and /dev/ttyf2 with the proper cables. I've reset the modem to factory defaults and run 'fix-hayes' on it. Every time the same problem. Any ideas would be greatly appreciated. Thanks Bob Munroe TOPIX Computer Graphics + Animation, Inc. topix@utcs.utoronto.ca 416.971.7711
vjs@rhyolite.wpd.sgi.com (Vernon Schryver) (05/26/91)
In article <1991May25.021412.6558@gpu.utcs.utoronto.ca>, topix@gpu.utcs.utoronto.ca (R. Munroe) writes: > I'm having a bit of strange trouble with a Hayes Ultra 9600 Smartmodem > hooked up to a PI 25. I can dial out O.K. I also have no trouble > dialing in - the modem connects, I get my login prompt, etc. The trouble > starts when I issue a command who's output is more than 5 or 6 lines. > For example, if I issue an 'ls' command, the first 4 lines of my > directory listing print out fine. The next line is completely garbled > and the following lines don't print. .... I assume a Hayes Ultra 9600 is a v.32 compatible modem. You don't say what sort of garbling happens. However, I bet it's missing characters. I bet the problem is that: -your modems are talking to each other slower than to the IRIS +modems using 2400 bits/sec (v.22) and IRIS-modem interface is at 9.6 or 19.2 b/s +modems using 9600 bits/sec (v.32) and IRIS-modem interface at 19.2 b/s -the modem is not doing any flow control because +the cable is wrong (not 7 correct wires) +not using the ttyf* name +modem is not capable of or configured to use RTS/CTS flowcontrol +IRIS and/or modem not set to use in-band, XON/XOFF flow control -as a result of the speed mismatch, the IRIS is overrunning the modem buffer. Please note that fix-hayes is for the ancient "Hayes 2400 Smartmodem." I have no idea what effect it has on this new modem. Vernon Schryver, vjs@sgi.com