opcode: processor:  remark & remedy:


AAA           i80286 & i80386 & i80486

CMPS           i80286
CMPXCHG        i80486
FINIT
FSTSW
FSTCW


INS            i80286 &
           i80386 &
           i80486

INVD           i80486



MOV to SS   n/a    early 8088  Some early 8088 would not properly
                   disable interrupts after a move to
                   the SS register. Workaround would
                   be to explicitly clear the
                   interrupts, update SS and SP and
                   then re-enable the interrupts.
                   Typically this would occur in a
                   situation where one would relocate
                   a stack in memory, more than 64Kb
                   from the original one, updating
                   both SS and SP like in:
                     MOV SS,AX  ; would disable
                          interrupts
                          automatically during
                          this and next
                          instruction.
                     MOV SP,DX  ; interrupts disabled
                     ...    ; interrupts enabled.


multiple prefixes
with REPx      8088 & 8086 They would not properly restart at
                   the first prefix byte after an
                   interrupt. when more than one
                   prefix is used. e.g. LOCK REP MOVSW
                   CS:[bx]. A workaround is to test
                   after the instruction for CX==0,
                   here: LOCK REP MOVSW CS:[BX] OR
                   CX,CX JNZ here because of the CS
                   override, the REP and LOCK prefixes
                   would not be recognised to be part
                   of the instruction and the REP MOVSW
                   would be aborted. This also seems to
                   be the case for a REP MOVSW CS:[BX]
                   Note that this also implies that
                   REPZ, REPNZ are affected in SCASW
                   for instance.