OEL TTX2000 Issue 2.3: Routine at 0292

0292: decode_magazine_number: Get the magazine number from the Magazine Row Address Group.

Used by the routine at NMI_ISR.
decode_magazine_number	0292	CALL hamming_decode_hl	Hamming 8/4 decode the byte at address in HL.
	0295	LD A,B	Return if result is $FF.
	0296	CP $FF
	0298	RET Z
	0299	AND $07	Else return magazine number in B.
	029B	LD B,A
	029C	RET