Chapter 5: Miscellaneous General Information; Monitor Rom - Nintendo GAME BOY Programming Manual

Game Boy Programming Manual

CHAPTER 5: MISCELLANEOUS GENERAL INFORMATION

1. MONITOR ROM

The DMG and CGB CPU includes internal monitor ROM.
When power on the hardware is turned on, the monitor ROM checks for errors in the
'Nintendo' logo character data within the game software.
If the data is correct, the Nintendo logo is displayed and the program is then started. If there is
an error in the data, the screen flashes repeatedly.
For information on registering the Nintendo logo character data, refer to Appendix 3 of this
manual, Submission Requirements.
The conditions required for starting the user program are as follows.
Starting Address
LCDC value 91h
Stack value FFFEh
150h (default value)
126
The starting address can be freely set
by writing a jump destination address
at 102h and 103h.