To call the firmware through these vectors, use an NOT1 EXT,0 instruction immediately followed by a JMPF to the entry vector. This will switch in the firmware and continue execution at the correct location. When the firmware is done, execution will resume at the indicated exit address. Input/output variables are located in RAM bank 1.

This call writes 128 bytes of data into the FLASH ROM at a specified location. B, C, TRH, TRL, XBNK and memory location 0 are scratched.

Input variables:

07C

Finalize flag. 1 = wait indefinitely for last byte to stabilize

07D-07F

Start address (24 bits big endian) (must be divisible by $80)

080-0FF

Data to write

Output variables:

ACC

0 = write ok, $FF = illegal write (only allowed to write inside mini-game file)

Exit address: 105

This call verifies 128 bytes of data in the FLASH ROM at a specified location. TRH, TRL and memory location 0 are scratched.

Input variables:

07D-07F

Start address (24 bits big endian) (must be divisible by $80)

080-0FF

Data to verify

Output variables:

ACC

0 = verify ok, not 0 = verify failed

Exit address: 115

This call reads 128 bytes of data from the FLASH ROM at a specified location. ACC, TRH, TRL and memory location 0 are scratched.

Input variables:

07D-07F

Start address (24 bits big endian) (must be divisible by $80)

Output variables:

080-0FF

Data read

Exit address: 125

This call should be made whenever a Timer 1 interrupt (vector 001B) occurs. It updates the system date/time, and performs other housekeeping duties.

Exit address: 139

This call exits game mode (and proceeds to clock mode). It should be made when the user presses the MODE button, or when the least significant bit of P7 is high. This call never returns.

Note that these variables are located in RAM bank 0.

Address Description 010-015 Buffer used by clock mode to convert current date and time to BCD (Binary Coded Decimal) 017 Current date, year (high byte) 018 Current date, year (low byte) 019 Current date, month 01A Current date, day 01B Current time, hour 01C Current time, minute 01D Current time, second 01E Current time, halfsecond (0 or 1) 01F Current time, leapyear (odd = leapyear, even = not leapyear) 031 Clock initialized flag. $FF means date set, $00 means date not set. 050 Current date, year divided by four (high byte) 051 Current date, year divided by four (low byte) 060 Cursor position, column (0-7) 061 Cursor position, row (0-3) 06D Last block used by mini-game 06E Battery check flag. $FF = disable automatic battery check, $00 = enable automatic battery check. 080-0FF Stack