Boot keys

Some special functions of the Mega-Cart can be accessed by holding down various keys while booting the Vic-20:

Key	Information
	Enter the Service Menu
	Restart the last selected item
	Select a menu tune
	Start the Vic Unexpanded (with 32K Read-Only, No auto start)
	Start the Vic +3K Ram (with 32K Read-Only, No auto start)
	Start the Vic +32K Ram (No auto start)
	Start the Vic-20 fully Expanded with EASYLOAD+ in RAM on BLK 5
	Lock the Cartridge games menu [1]
	Lock the Tape/Disk games menu [1]
	Lock the Utilities menu [1]
	Lock the Normal Reset menu [1]
	Lock Soft Reset menu [1]
	Lock the Last Selection [2]
	Unlock previous selection (keys 1-6) and enter the Early Startup menu

In the Download section you can find a handy Vic-20 keyboard overlay by Brent Santin that shows all boot keys.
 

[1]	When you "lock" a certain menu, you limit the Mega-Cart to displaying only the "locked" menu on subsequent boots.  You can re-enable the Early Startup Menu by holding down the “0” (zero) key while booting.

[2]	When you "lock" the Last selection, you limit the Mega-Cart to always starting the last item selected on subsequent boots (be it a game, utility or Memory configuration). You can re-enable the Early Startup Menu by holding down the “0” (zero) key while booting.