Does anyone know the physical to functional keybindings for early LISP Machine keyboards, Symbols, Knight, Space Cadet etc featured here:

http://xahlee.info/kbd/lisp_keyboards.html

I did an analysis against the Space Cadet against my iMac Bluetooth keyboard. Here are some rough samples because physical mapping is not 1-1:

iMac. Symbolics Space Cadet Command Left/Right Space or no key Option Left. Control Control Left. Control Fn Left Meta Option Right. Control Left Arrow Right. Control Up/Down Arrow Right Meta Caps Lock Alt Mode or Rub Out (Delete under char?) Tab Network or Tab To further summarize my inquiry, I'm wondering:

o If there was any physical reason for the placement of the keys on the early LISP keyboards? Perhaps frequency of that particular input as a key in editing LISP code? o Is there any key mapping of these LISP machine keyboards to Emacs functions? (Emacs had been around at that time) o Did the Emacs functional keybindings (M-x) for instance change over time? For instance did the early LISP keyboards Meta key + x, correspond to M-x of was it different? o Has anyone created a similar physical mapping of the iMac Bluetooth keyboard with above in mind from a physical to Emacs functional perspective?

I also noted that there are arrow keys above g,h,k,l. For instance, were these used to move the cursor? If so, I would argue they are better placement then modern arrow keys and/or Alt-n Alt-p, for cursor movement. I'm also suspicious that the Space Cadet ALT MODE which is close to the iMac TAB may be the original mapping to Meta functionality because it corresponds easily to the pinky figure.

Finally, does someone have one of these keyboards because I would love to try one out. :)

Appreciate anyone's guidance on this.