Discuss A bus, B bus and C bus and mention their uses.

A bus is the internal 16-bit ALU data bus: C-Bus is the internal 20-bit address bus, 16-bit data bus, and possibly control lines of the BIU bus.

B-bus has no true name but the function of the adder ALU is to add the shifted 16-bits (Starting Address of 64 Kbyte segment) CS (Code Segment) to the 16-bits IP (Instruction Pointer Offset into CS for next instruction) to get the 20-bit Physical Address. The right side of both diagrams allows the segment registers to be accessed B-bus's name would be offset bus.