collapseos/blk/565

Sending 0xff to the port resets the keyboard, and then we have
to send groups we want to "listen" to, with a 0 in the group
bit. Thus, to know if *any* key is pressed, we send 0xff to
reset the keypad, then 0x00 to select all groups, if the result
isn't 0xff, at least one key is pressed.
ti84: kbd driver wip 2020-05-10 01:55:58 +10:00			`Sending 0xff to the port resets the keyboard, and then we have`
			`to send groups we want to "listen" to, with a 0 in the group`
			`bit. Thus, to know if any key is pressed, we send 0xff to`
			`reset the keypad, then 0x00 to select all groups, if the result`
			`isn't 0xff, at least one key is pressed.`

VE: add 't' This is the first commit I do entirely in VE. It's a habit I'm planning on taking as it helps a lot to find usability issues. 2020-06-12 08:12:01 +10:00