The Help-Key is read from KBCODE and stored in HELPFG. There is no normal action when HELP is pressed. The programmer has to check HELPFG or KBCODE.

Bits

Bit 0 HELP
Bit 4 HELP
Bit 6 SHIFT
Bit 7 CTRL

Value

$00 HELP Flag cleared
$11 HELP key pressed
$51 SHIFT HELP pressed
$91 CTRL HELP pressed