terminal drivers should not write errors to stdout and call exit()
Remove vestigial files from the era of 16-bit DOS
Remove vestigial driver and makefile for the AT&T 3b1 "unix pc"
Remove vestigial driver and makefile entries for the AT&T 3b1 "unix pc"
Remove vestigial driver and makefile entries for the AT&T 3b1 "unix pc"
Remove vestigial driver and makefile for the AT&T 3b1 "unix pc"
Add private handlers gp_exit() and gp_atexit()
Remove vestigial files from the era of 16-bit DOS