KC compact

The KC compact was the last 8-bit mini-computers ( home computer ) Made in the GDR at 4 MHz and 64 KB RAM. The computer is a replica of the Amstrad / Schneider CPC and comes from the VEB Microelectronics " Wilhelm Pieck " Mühlhausen ( combine microelectronics Erfurt). The KC compact was ready for series production until the end of the GDR ( ironically, as a gift for the 40th birthday Republic ), therefore only a few units are produced and sold.

Computernachbauten in the Eastern Bloc

During the Cold War and the associated trade restrictions it was quite common in the Eastern Bloc, to get Microelectronics and even whole computer on any trails in the west and analyze by the method of reverse engineering. Subsequently, the devices were reconstructed with the available resources in the east. Demand gaps could be closed relatively easily, also formed one specialist approach. A good and well-known example is the numerous spectrum clones of the Soviet bloc, but also IBM-compatible mainframes, especially the Unified System Electronic Computing Technology, are beyond the " Iron Curtain " appeared.

Hardware

The computer consists of a base unit with external power supply. It was used the same case as the BIC, but the electronics are not interchangeable. The following connections are available at KC:

Because of the additional high- voltage supply for external devices attached caution when connecting CPC original parts.

In the computer, a UA880 CPU, which is based on the U880 works. Of the 64 KB RAM serve a default of 16 KB as a frame buffer. This allows for the 640 × 200 points 2, 200 points 16 represent from 27 colors at 320 × 200 points 4 and at 160 ×. The screen control is realized as the CPC over a Motorola unconventional connected 6845; Therefore, the size and location of the image and frame buffer are very extensively programmable. The sound (AY sound chip ) was the early 90s are still classified as good and went well beyond the beep sounds of KC 85 series also. There are both envelopes and noise generated. A CIO circuit performs the functions of PIO and CTC. Some special circuits of the Western prototype were replaced by logic gates, a common method in the GDR.

As an auxiliary device and a floppy disk drive has been developed. Thus, the KC is CP / M -compatible compact principle.

Software

After the BASIC interpreter starts up, and you can immediately start to write programs. The BASIC is very comfortable ( just because that was copied from the CPC). Due to the software compatibility with the western CPCs can rely on a wide range of games and applications. From the Manufacturer few games as well as applications such as word processors, graphics programs and Pascal came as a programming language.

The KC compact and its technology

With 64 KB of RAM and BASIC 1.1 could this " CPC Calculator" between CPC 6128 and CPC 664 lane. Instead of CP / M operating system, a Germanized CP/M-2.2-Clone called MicroDOS was used, which was previously on various DDR machines in use. Software was therefore believed to be available.

Externally, the square - flat, light housing without drive the C64 -like than the CPCs, stuck under the keyboard a replica of the famous computer technology by other means. Was used, inter alia:

  • As CPU U880 (or UA 880D ), a Z80 Clone
  • A programmable " Zilog 8546 " -I/O-Baustein type U82536 instead of the special Amstrad blocks. Theoretically, this was possible 64 colors or more Assembler-I/O-Optimierungen.
  • More standard blocks from production of the GDR, the Soviet Union and other Eastern Bloc countries
  • One of the changed hardware custom ROM Content

External can be stated:

  • Standardized interfaces (DIN, Centronics interface, etc.)
  • An external power supply with further voltage reduction onBoard
  • Serves as storage medium - in contrast to the special datasettes such as used in the Commodore C64 - a commercially available tape drive or an external 5 ¼ " floppy disk drive, which via an external, like the CPC 464 as" will Backpack " mounted controller, connected in this compact additional 64 KB of RAM were in the case of KC contain so. that such an equipped KC compact largely the Amstrad / Schneider CPC6128 corresponded.
  • A prev. the original CPC extended power supply for external peripherals via the standard interfaces.
  • A (direct ) connection for a monitor or TV

The replica is so successful that the compatibility of something from another machine is to estimate the range of the CPC computer even within ( ). The hardware interfaces are only partially identical, individual Views differ, it was another peripheral is connected. Whether any changes to the chipset hardware possible I / O performance improvements were ever utilized is questionable.

When two computers connected by means of cable was unique within the CPC series possibility to clone the memory contents of the respective other computer. This is likely to have been intended focus like for program development and the thereby necessary test runs.

Unconfirmed is the production time between October 7, 1989 (DDR- anniversary ) and 1990 ( reunification ). Any dissemination, quantities or use of the computer within the GDR ( still) is not known. Due to the short production time and associated low -volume functional compact KC have a high collector value that significantly exceeds that of his Western brothers.

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