IBM 5170 Technical Reference page 338

CLD
=
Clear Direction
Clear Direction
111111100
STD
=
Set Direction
Set Direction
111111101
CLI Clear Interrupt
Clear Interrupt
1 11111010
STI
=
Set Interrupt
Set Interrupt
1 11111011
HLT
=
Halt
Halt
111110100
WAIT
=
Wait
Wait
1 10011011
LOCK
=
Bus Lock Prefix
Bus Lock Prefix
111110000
CTS
=
Clear Task Switched Flag
Clear Task Switched Flag
1 00001111 1 00000110
ESC
=
Processor Extension Escape
6-20 Instruction Set