The Silex SIL'Z III was a Z80 based CP/M computer. Leanord produced mostly computers based on existing models, as they had given up on producing their own designs. This computer looked very similar to the original Silex, but instead of being an Apple II clone, this computer was running Digital Research CP/M v2. The CPU was a Zilog Z80A clocking in at 2.5MHz and the computer came standard with 64kByte of RAM.

The SIL'Z III offered enhancements over the SIL'Z II such as increased storage options and improved peripheral interfaces. These upgrades made the SIL'Z III more versatile for business and educational applications.

The built in 12" monochrome screen could produce 80x24 text. The case could fit two 5.25" disk drives, or could be equipped with a Winchester 5MB or 10MB hard drive. Other optional peripherals were a modem card and a networking card.

Leanord is the name of a computer hardware company from Lille France. It was founded by Bernard Pronier. After producing and marketing a few orignial microcomputers, Leanord produced an Apple II clone which was branded the Leanord Silex. When CP/M became more or less a standard operating system, driven by Digital Research, the company switched and started producing Z80 based systems, such as the SIL'Z 3 and later produced Intel 8088 based MS-DOS machines like the SIL'Z 16. Leanord kept producing clones, in fact,t he SIL'Z 16 is a clone of the American FX20 by Future Computers. Leanord made some modifications so it could produce the computer on its assembly lines in Lille, but it basically remained the same machine as the FX20.

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.