IBM AT 5170 Technical Reference page 372

Register
01010reg
Segment Register
OOOreg 110
Immediate
011010s0
data data
if
s 0
PUSHA
=
Push AIl
01100000
POP
=
POp
Memory
\
10001111 modOOO rim
Register
I
01011reg
Segment Register
OOOreg111
reg ". 01
POPA
=
Pop AIl
01100001
XCHG
=
Exchange
Register/Memory with Register
1000011w
mod reg rim
Register with Accumulator
10010reg
6-4 Instruction Set