All of this is possible, though a little complicated. The getKey command returns a number corresponding to the latest keypress on the keypad. For instance, if getKey is used while ENTER is pressed, a 105 will be returned, and if 7 is pressed, a 72 will be returned. Here's a handy chart for the getKey codes:

So, while Input cannot run alongside an event loop, a getKey and some ingenuity can. The following code snippet will store input from getKey (provided it was a number) into an accurate numerical value in N. When combined with the previous code, we can produce a multi-digit number inputter alongside a running timer.

Code:

Now that snippet can be integrated into the previous code. The following code will visibly count down a timer (currently set at 500 seconds), while at the same time accepting user input (from the number keys) and displaying that on the screen. Pressing enter or time ending will display win/loss results. The only way to win is to press enter before the time runs out, and have the inputted number be identical to a 10 digit max number stored in L2. Put the number in L2 before the program starts. For instance, if you want the required number to be 276475, store {0,0,0,0,2,7,6,4,7,5} to L2. I have not yet implemented only accepting input after a certain time.

Code:

If you look closely at the getkey chart, you will notice that it is simply ROWcolumn, where 'ROW' is the row (with the keys on the top layer being one), and 'column' being the column number, with 1 being on the far left and 5 being on the far right. The arrow keys are a little haphazardly named (in my opinion), but memorizing 4 keys is better than memorizing ~50 keys!

EDIT: getkey always returns a number, if there is no key, then it returns 0.

The arrow keys match the ROWcolumn convention... Its just that they dont fall on exact rows so they had to make do with that. Where they are weird is in the getCSC codes, where they are 1,2,3,4

I noticed the topic title change. The final answer is that the TI-84 Plus CE, being a single-core computer, can only run one process at once. However, simultaneous processes can be synthesized using smart coding.

In response to your previous post asking for me to elaborate, I swear I could have seen a page on TI-BASIC dev that said that other commands could be run while another command was running, which I remember being the seq( command. (IIRC)

I think it was either for a different calculator, or wishful hoping by the author.

Here, have some optimizations:

Code: