11

The zeropage address 11 ($0B in hexadecimal) is used as a "working" register" by several routines in BASIC ROM for a variety of purposes:

• It is used as a temporary storage for most recent BASIC token.
• When editing/inserting lines in a BASIC program, this address holds the length of the edited or new line.
• The BASIC operators AND and OR are handled by the same routine in BASIC ROM, so to distinguish between the two operations address 11 is used as a flag to indicate which operation to perform.
• When handling an array, BASIC uses address 11 for holding the number of dimensions in the array.