The 186 had another condition flag for 'segment prefix present' and decremented PC twice if it was set: ** 0.1010101x STOS 0 IK -> IND 0 F1 6

The 186 had another condition flag for 'segment prefix present' and decremented PC twice if it was set: ** 0.1010101x STOS 0 IK -> IND 0 F1 6 ;check count if repeated 1 M -> OPR 6 W DA,BL 2 1 DEC tmpa 3 IND -> IK 0 NF1 7 ;exit if no repeat 4 SIGMA -> BC 5 INT RPTI ;handle interrupt 5 BC -> tmpa 0 NZ 1 ;redundant check??? 6 BC -> tmpa 0 NBCZ 1 ;loop while Not BC Zero 7 4 none RNI ** 1.10100100 string instr interrupted (RPTI:) 0 PC -> tmpb 4 none SUSP 1 1 DEC tmpb 2 SIGMA -> tmpb 0 F1 5 3 0 PFX 6 4 SIGMA -> PC 4 FLUSH RNI ;PC corrected 5 SIGMA -> tmpb 0 UNC 3 ;has REP 6 SIGMA -> tmpb 0 UNC 4 ;has seg pfx 7 4 none none edit - Posting code for STOS since it's simple, even though segment prefixes don't affect its function. - No idea if line 5 could be removed, maybe needed for timing? - MOVS, INS and OUTS use a special memory-to-memory/IO operation encoded as 'W IRQ DD,BL'. It doesn't use the IND register at all, maybe the internal DMA controller instead?