I realized the CL1000M KVM cable has been changed from

2L-5202P to 2L-5202UP and would like to know the difference.

The 2L-5202P uses PS2 server connectors for mouse and keyboard.
The 2L-5202UP uses USB server connectors for mouse and
keyboard.

PS/2 and USB protocols are different so the UP cable has built
in intelligence

to convert PS/2 signals to USB.