IBM AT 5170 Technical Reference page 380

STOS
=
Store Byte Word from AL/AX
1010101w
INS
=
Input Byte from DX Port
0110110w
OUTS
=
Output Byte Word to DX Port
0110111w
REP/REPNE, REPZ/REPNZ
=
Repeat String
Repeat Move String
11110011
1010010w
Repeat Compare String (z/Not z)
1111001z 1010011w
Repeat Scan String (z/Not z)
1111001z 1010111w
Repeat Load String
11110011 1010110w
Repeat Store String
11110011
1010101w
Repeat Input String
11110011 011011 Ow
Repeat Output String
11110011 1010011w
6-12 Instruction Set