Robotron PC / KC
Robotron A5105  (1989)
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Robotron A5105 (BIC)

The Robotron A5105 was also dubbed BIC, which stands for Bildungs Computer (trainings computer in English). The system had many improvements over the KC85 line of computers. It had a much better keyboard, and was much faster then the older line. It had a dedicated graphics chip, which could produce 16 colors, and came with it's own 128KByte dedicated Video RAM. Oddly, the system came with a monochrome monitor.

The system could run CP/M using a special driver for the FDD controller. The computer was manufactured in East Germany between 1989 and 1990, and only around 5000 units were ever produced.

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.

Technical Details
Released
1989
Country
East Germany (DDR)
Brand
VEB Robotron
Type
Robotron PC / KC
Name
Robotron A5105
CPU Class
Z80
CPU
U880 (Z80 clone) @ 2.5/4MHz
Memory
RAM: 64kB
ROM: 16kB
VRAM: 16kB
Sound Chip
none
Sound
Simple built in beeper
Display Chip
need info
Display
need info
Best Text
40x24
Best Color
16 colors
4-bit palette
Graphics
320x256 in 16 colors
Sprites
n/a
System OS
KC87 OS & BASIC
Storage
3.5" Floppy disk (720kB)
External Links 🌐
U880 CPU (Z80 clone)
Wikipage for the U880 CPU, an East German Z80 clone
Z80 CPU
Wikipedia page on the very popular Z80 8-bit CPU used in many computers of the 1980's era.