Robotron PC 1715
The Robotron PC 1715 was a Zilog Z80 based CP/M machine produced in East Germany in the mid-eighties. It was used mainly as office and educational computer. As many Eastern European computers of the time, it was mainly made with elementary TTL logic, as those parts were more readily available in the EastBloc countries.
The machine had no sound or graphics, but there are some prototype graphic mode expansion cards floating around. The first PC1715's were equiped with 360K/400K disk drives, but later versions were shipped with a single 800K drive.
CPU - The U880 (Z80 clone)
The U880 is an 8-bit microprocessor that was manufactured by VEB Mikroelektronik "Karl Marx" Erfurt (abbreviated as MME; part of Kombinat Mikroelektronik Erfurt) in the German Democratic Republic.
The U880 was first manufactured in 1980 at VEB Funkwerk Erfurt, this plant was renamed to VEB Mikroelektronik "Karl Marx" in 1983. The U880 is an unlicensed clone of the Zilog Z80 microprocessor. It even supports all the illegal opcodes and bugs, except for very minor differences like not setting the CY flag for the OUTI command (when L goes zero).
CPU - The Zilog Z80
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.
ROM: 2kB
Basic
