The U880 is an unlicensed clone of the Zilog Z80 microprocessor, also supporting illegal opcodes and bugs, except for very minor differences like not setting the CY flag for the OUTI command (when L goes zero).

The U880 was manufactured in NMOS technology and encased in a plastic DIL40 package with a pin spacing of 2.5 mm[3][4] (export versions had the Western pin spacing of 2.54 mm; Russian variants also came in a ceramic package).

The prefixes UA, UB, VB, 80, and 80A correspond to the same temperature ranges and clock rates as for the processor variants above.

Only clones of the Intel 8080 were manufactured in Poland, Czechoslovakia, Hungary, Romania, and the Soviet Union.

When MS-DOS emerged as the dominant operating system for personal computers, in the Eastern Bloc the only available clone of the Intel 8086 was the Soviet K1810VM86.