Int 21H, AH=0BH

1 and higher

GET STDIN STATUS

DosRead

AH = 0Bh

AL = status 00h if no character available FFh if character is available

^C/^Break are checked, and INT 23 is called if either pressed

standard input is always the keyboard under DOS 1.x, but may be redirected under DOS 2+

if the interim console flag is set (see AX=6301h), this function returns AL=FFh if a partially-formed double-byte character is available

AH=06h“INPUT”,AX=4406h

Text based on Ralf Brown Interrupt List Release 61