+/*
+SR format:
++--+--+--+--+ +--+--+--+--+ +--+--+--+--+ +--+--+--+--+
+|T1|T0| S| M| |--|I2|I1|I0| |--|--|--| X| | N| Z| V| C|
++--+--+--+--+ +--+--+--+--+ +--+--+--+--+ +--+--+--+--+
+ T - Trace (T1 only in 68K, T0 = 0)
+ S - Supervisor flag
+ M - Master/Interrupt flag (= 0 in 68K)
+ I - Interrupt level mask
+ X - Extend flag
+ N - Negative flag
+ Z - Zero flag
+ V - Overflow flag
+ C - Carry flag
+*/