Volex TTX2000 S Issue 1.2: Routine at 09C9

09C9: mosaics_colour_code: Handle a mosaics colour code.

Used by the routine at decode_row.
mosaics_colour_code	09C9	XOR A	Clear conceal_flag.
	09CA	LD (conceal_flag),A	Clear conceal_flag.
	09CD	LD A,(character_code)	Subtract 16 from character_code (turn it into equivalent alpha colour code) and store result back in character_code and mosaics_flag.
	09D0	SUB $10
	09D2	LD (mosaics_flag),A
	09D5	LD (character_code),A
	09D8	CALL translate_colour	Translate alpha colour code to ink colour.
	09DB	LD A,(hold_mosaics_flag)	If hold mosaic flag is set copy hold_mosaic_character to character_code.
	09DE	AND A
	09DF	JP Z,code_set_after
	09E2	LD A,(hold_mosaic_character)
	09E5	LD (character_code),A
	09E8	JP code_set_after	Jump into display character routine at code_set_after.