It was linked a little up thread, but since you’re (probably) referring to the “Space-cadet” keyboard, it was seven.
Technically, they drew a distinction between the “shift” keys (of which there were three), and the other modifiers (four).
In modern times (or for Linux at least), Meta has essentially coalesced with Alt, so the modifiers we’ve retained are Control, Alt, and Super (Windows), with only “Hyper” having been lost along the way.
The remaining two shifts (also lost to time) were “Top” (symbols) and “Front” (Greek), with the Greek supporting combining with shift (there’s a table on that Wiki page).
It was linked a little up thread, but since you’re (probably) referring to the “Space-cadet” keyboard, it was seven.
Technically, they drew a distinction between the “shift” keys (of which there were three), and the other modifiers (four).
In modern times (or for Linux at least), Meta has essentially coalesced with Alt, so the modifiers we’ve retained are Control, Alt, and Super (Windows), with only “Hyper” having been lost along the way.
The remaining two shifts (also lost to time) were “Top” (symbols) and “Front” (Greek), with the Greek supporting combining with shift (there’s a table on that Wiki page).
I believe this same keyboard is why certain Vim keybindings are the way they are, like the arrow keys were on hjkl,