ChrS returns a string the only character of which has the value of the integer i. This function implements the BASIC CHR$ function.
These routines perform no real conversion between the integers and characters. The characters are regarded as one byte numeric values. If one regards the characters as ASCII symbols, then a mapping occurs between the symbol and its code number.
ChrS generates error 5 (Illegal function call) if i is negative or greater than 255.
from The Basmark QuickBASIC Programmerís Manual by Lawrence Leinweber