Don't use the input function. You would have to create your own function to input the number that would allow for the backspace key being pressed. This could get quite involved since you would have to catch the scancode of the number being pressed and turn that into an ASCII number. Something like...
function _input()
s=scancode()
if scancode=2 then a$=a$+"1"
if scancode=3 then a$=a$+"2"
if scancode=4 then a$=a$+"3"
if scancode=5 then a$=a$+"4"
if scancode=6 then a$=a$+"5"
if scancode=7 then a$=a$+"6"
if scancode=8 then a$=a$+"7"
if scancode=9 then a$=a$+"8"
if scancode=10 then a$=a$+"9"
if scancode=11 then a$=a$+"10"
if scancode=14 then a$=left$(a$,len(a$)-1)
if scancode=28 then A=val(a$) : exit
endfunction A
I find it strange that the backspace key no longer works on an input function, I wonder if this is a known bug or it is intentional.
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