F3               1478 src/dps8/dps8_cpu.h #define F3 Fk [0]
F3                750 src/dps8/dps8_ins.c     putbits36_1  (& words[6], 31, cpu.du.F3);
F3                801 src/dps8/dps8_ins.c     cpu.du.F3       = getbits36_1  (words[6], 31);