The Lambda 8300 was a Sinclair ZX81 clone. It was available in the United States as the PC8300. The machine was developed by Lambda Electronics Ltd from Hong Kong. The ROM was a modified version, and the machine had some extra hardware, making the machine not fully compatible.

The 8300 came with 2kByte RAM, which could be expanded to 32kBytes. The ROM contained extra semigraphic characters. The ROM could be swapped out for a real ZX81 ROM for complete compatibility. Additionally, a custom ROM was developed by Fred Nachbauer. He used a modified Timex/Sinclair 1000 ROM. The PC8300 ROM was a 24-pin 8K ROM, and the newly adapted ROM was an 28pin EPROM. The extra pins had to be removed so that the ROM could be used in the Lambda 8300. This ROM achieved about 90% compatibility.

The Z80 quickly became popular in the personal computer market, with many early personal computers, such as the TRS-80 and Sinclair ZX80, using the Z80 as their central processing unit (CPU). It was also widely used in home computers, such as the MSX range, SORD, and the Amstrad CPC, as well as in many arcade games. Additionally, it was also used in other applications such as industrial control systems, and embedded systems. The Z80 was widely used until the mid-1980s, when it was gradually replaced by newer microprocessors such as the Intel 80286 and the Motorola 68000.

The Z80 microprocessor was developed by Zilog, a company founded by Federico Faggin in 1974. The Z80 was released in July 1976, as a successor to the Intel 8080. It was designed to be fully compatible with the 8080, but also included new features such as an improved instruction set, more powerful interrupts, and a more sophisticated memory management system.

Originally the Z80 was intended for use in embedded systems, just as the 8080 CPU. But the combination of compatibility, superior performance to other CPUs of the era, and the affordability led to a widespread use in arcade video game systems, and later in home computers such as the Osborne 1, TRS-80, ColecoVision, ZX Spectrum, MSX, Sega's Master System and many more. The Z-80 ran the original Pac-Man arcade cabinet. The Z-80 was used even in the Game Gear (1990s), and the TI-81 and succeeding graphic calculators.

The Z-80 remained in production until June of 2024, 48 years after its original release. Zilog replaced the processor with its successor the eZ80, an 8-bit microprocessor that features expanded memory addressing up to 16 megabytes, and running up to 50MHz, comparable to a Z80 clocked at 150MHz.