The SN54165 and SN74165 devices are obsolete and a.
SN74LS165A - Parallel-Load 8-Bit Shift Registers
The SN54165 and SN74165 devices are obsolete and are no longer supplied. SN54165, SN54LS165A, SN74165, SN74LS165A PARALLEL-LOAD 8-BIT SHIFT REGISTERS.