6. The "F" key sets a called subroutine to run at full speed.
7. The "S" key sets a called subroutine to run at trace speed.
8. The "B" key causes the memory display to be in byte format
   with the ASCII characters displayed also.
9. The "W" key causes the memory display to be in word format.
10. The "PgUp" and "PgDn" keys will display the previous or next
    256 bytes of memory.
11. The "up arrow" and "down arrow" on the numeric key pad will
    display the previous or next 16 bytes of memory.
12. The "left arrow" and "right arrow" on the numeric key pad will
    display the previous or next byte of memory.
13. The "F3" key will toggle between the last and current instruction.
    The single step mode must be used for two instructions before
    using the F3 key. Also the white line must be on the current
    instruction in order to continue tracing.
14. The "F4" key toggles between displaying hex numbers in upper
    or lower case.
15. The "F5" key toggles between showing or not showing ASCII characters
    in memory monitor, when in byte mode.
16. The "Esc" key ends the demonstration and returns to DOS.