Tom Lake wrote: > I have an ASR-33 Teletype on ttyS0 which can only output uppercase > characters that I'm trying to use as a serial console.
I like it. > My getty specifies -U to allow for uppercase terminals. > ... > As you can see, iuclc is clearly in effect but > the conversion from uppercase to lowercase isn't being done. > No commands work, and I had to create a user with an uppercase-only > password just to be able to log in at all. I can recreate your problem on my Debian Linux 2.6.26 kernel. The 'olcuc' has effect but 'iuclc' doesn't seem to function at all. I may be missing something but at this point I agree with you that this is a bug and one that I would not have expected to see in such an old interface. I guess no one uses uppercase only terminals anymore. :@) > Shouldn't stty have converted the uppercase input to lowercase? The 'stty' command sets tty driver controls. It isn't the actual code that does any of these conversions. The driver in the kernel is responsible for that behavior. The 'stty' command is simply one interface to change or display those settings. To me the problem appears to be in the Linux kernel. > If I set iuclc on tty0 (the normal console) it works as expected and > I can turn on Caps Lock and still execute commands and cp tty0 test > does put lowercase characters in test regardless of the state of Caps > Lock. The Linux console uses a different driver from the serial terminal which uses a different driver from the pseudo-tty driver used for terminals on the graphical display. It is certainly possible for them to suffer from different bugs and differing behavior. > Is this a bug in stty? I don't think the bug is in stty. It would only be setting ioctl values and displaying those values. The kernel driver would be responsible for all of the work. The kernel is what is actually reading and writing characters. Plus the behavior is working for ptys. At first glance in my mind everything is pointing to a problem in the Linux tty serial driver. I think you need to report the problem against the Linux kernel. That can be a harsh place for people to start. Since you are using Ubuntu I recommend that you report the problem against the Ubuntu linux-image-2.6-686 package and get some help working through the problem from the distro package team. This is interesting to me so if you would be so kind please let me know how you report it so that I can track it and perhaps help in the testing. > If so, I'd like to get a fix so I can use my terminals in a local > antique computer museum. I think that is a pretty cool idea. I hope you can do this. Bob
