ADM3a keyboard, Hazeltine.. my TRS-80 didn't have it (I modded the keyboard, and wrote my own keyboard driver in assembly)
the way a keyboard was meant to be:
See wikipedia: Control key for more info and some history.. anyway, one of the first things I do on a computer to make it usable is fix it so the key to the left of 'A' functions as control.
For windows xp and since (maybe going back to win95 ?), a registry entry can fix this.
The following in a .reg is sufficient:
A collection of .reg files for quick setting and resetting is here: howto geek windows key mappings.
And after you set it, you have to reboot for it to take effect, because this is windows. (I discovered going to the 'switch user' screen and coming back works.)
For X11, a small file for input to xmodmap(1) can do this; specific settings are included in the man page.