Holy cow, I wrote a book!
For one thing,
the cash register has only ten letters of the alphabet on it.
You have to switch to the alternate keyboard for the rest.
Also, there is a backspace key but no other editing keys.
Finally, there is a key labeled ≔
which changs the formatting to multi-person mode.
Okay, this doesn't actually make typing more difficult,
but it's still something unusual.