Segment Override Prefix; Use Of Segment Override - IBM XT 5160 Technical Reference

Segment Override Prefix
OOlregllO
Use of Segment Override
Operand Register Default With Override
Prefix
IP (Code Address) CS
SP (Stack Address) SS
BP (Stack Address or Stack Marker) SS
SI or DI (not including strings) DS
SI (Implicit Source Address DS
for strings)
DI (Implicit Destination Address
ES
for strings)
6-6
Instruction Set
Never
Never
BP
+
DS or ES,
or CS
ES, SS, or CS
ES, SS, or CS
Never