FAULT_F1          803 src/dps8/dps8_addrmods.c                 doFault(FAULT_F1, fst_zero, "IT_MOD: IT_F1");
FAULT_F1         9937 src/dps8/dps8_ins.c 
FAULT_F1         9984 src/dps8/dps8_ins.c         fi_addr == FAULT_F1  ||
FAULT_F1         4106 src/dps8/dps8_sys.c     SYMTAB_ENUM32 (FAULT_F1),