The Robotron 5120
The Robotron 5120, launched in 1982 by the East German VEB Robotron, was a prominent example of computing technology from the Eastern Bloc during the Cold War era. This computer was designed primarily for scientific and business applications and was notable for its large, bulky build, weighing in at around 50 kilograms. It featured a black-and-white CRT display and was typically used for data processing, office management, and other professional applications within government institutions and enterprises. The 5120 was one of the successors in Robotron's line, aiming to standardize computing across East Germany’s industries, a necessary adaptation due to the limited access to Western technology.
At its core, the Robotron 5120 was powered by two U880 microprocessors. The U880 was a Zilog Z80 clone that operated at a clock speed of 2 MHz. One CPU was dedicated to I/O, while the other was the computers main processing unit. This CPU was accompanied by a memory capacity of 32 KB of RAM, expandable to 64 KB, and a ROM containing the system's basic instructions and operating system code. For storage, the 5120 initially used magnetic Cassette Drives, but it later models used two 5.25-inch floppy drives with a capacity of 256 KB each, which was quite advanced for computing systems in the Eastern Bloc at the time. The machine could run a custom operating system, SCP (System Control Program), a CP/M-inspired OS tailored to the Robotron’s hardware, which supported file management, basic applications, and custom software developed within East German institutions.
The Robotron 5120 was typically paired with a monochromatic monitor and a full-sized keyboard with additional function keys specific to its SCP operating system. Its software capabilities included text processing programs, spreadsheet applications, and custom-developed business software, catering to the needs of data-intensive tasks in government and enterprise environments. While slow by modern standards, the 5120's performance was adequate for the limited computational needs of the time, although its peripherals and expansion capabilities were constrained by state-controlled production limits. The Robotron 5120, thus, represents an interesting chapter in computer history, embodying the technological aspirations and limitations of East German industry during the 1980s.
CPU View - U880 CPU (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 View - Zilog Z80 Family
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.
The Z80 quickly became popular in the personal computer
RAM max: 64kB
ROM: 16kB Sound Chip none Sound Simple built in beeper Display Chip need info Display need info Best Text 40x24 Best Color need info Graphics need info Sprites n/a System OS SCP (CP/M clone) Storage 3.5" Floppy disk (720kB)