Example 1:

    GTM> FOR i=0:1:3 WRITE !,$A("HI",i)
    -1
    72
    73
    -1
    GTM>
    

This loop displays the result of $ASCII() specifying a character position before, first and second positions, and after the string.

Example 2:

    FOR i=1:1:$LENGTH($ZB) WRITE !,$A($ZB,i)
    

This loop displays the ASCII codes of the terminator in the Intrinsic Special Variable, $ZB. Generally this is 13, for <CR>, or an escape sequence.