MEMORY ORGANISATION INTIOROM is a soft-switch which controls the I/O ROM bank configuration. Soft- switch is widely used in the computer. The logical state of the soft-switch is set by software. A summary of all soft-switches are listed in Table 3-5. 3.2.1 The BASIC interpreter The address range is from $D000 to $F7FF. Details of the BASIC commands can be found in the user's manual. 3.2.2 The System Monitor The monitor occupies $F800 to $FFFF. The basic I/O subroutines are in the monitor. You can enter the monitor from BASIC by typing CALL-151 and pressing RETURN. 3-3