Hi, I have an actual VT420 terminal connected to ttyS0 of my Linux box, running Debian woody/testing, and am having trouble using certain programs (e.g. less, jed, emacs, etc.) on the terminal, though others (e.g. lynx, vim, more, etc.) run fine. I've tried configuring the VT420 through its setup both using Xon/Xoff (software) flow control and (probably) the preferred hardware (VT420 calls it modem) flow control (which uses DTR/DSR lines).
I'm runing agetty (Debian's getty) to set up the terminal login prompt: getty ttyS0 9600 vt420 (I also use the -h flag when I enable the DTR modem control in the VT420's setup.) The primary problem is that less, for example, automatically stops after displaying the first screen, jed stops immediately upon invocation, and emacs doesn't like to run with Xon/Xoff at all (which I believe is a known issue), but also displays lots of junk (probably buffer overruns) even when I use hardware flow control, which I believe should stop this. I thought it might be something with ncurses not getting along with my flow control, but my TERM environmental variable is properly set at 'vt420', and lynx works fine (and uses, I believe, ncurses). I'm wondering if, at least for the hardware modem flow control stuff, it might be that the linux kernel's serial driver doesn't support DTR/DSR flow control (I'm running 2.4.16 on this box), but I've not been able to get a good handle on whether this is true. Grepping through the serial.c source showed references to DTR/DSR, but none that enabled me to nail down its level of support. I believe that my cable is properly wired (followed vt100.net instructions). I have an MMJ null-modem cable, and connect TXD+ to pin 2, RXD+ to pin 3, DTR to pin 8, DSR to pin 7, and TXD- to pin 5 of my DB9 serial connector on my linux box. Anyway, bottom line, has anyone had success running these types of applications on a vt420 (or other vt) in a similar setup? Thanks so very much for any and all suggestions. Take care, Daniel -- Daniel A. Freedman Laboratory for Atomic and Solid State Physics Department of Physics Cornell University