Robotron Z 9001, Robotron KC 85/1, Robotron KC 87
| Robotron Z 9001, Robotron KC 85/1, Robotron KC 87 | |
|---|---|
 .jpg)
|
|
| Manufacturer | VEB Robotron measurement electronics "Otto Schön" Dresden |
| Type | Home computers |
| publication | Z 9001: 1984 KC 85/1: 1985 KC 87: 1987 |
| End of production | Z 9001: 1985 KC 85/1: 1987 KC 87: March 1989 |
| Factory price | Z 9001.10: 1550 Mark KC 85 / 1.10: 1550 Mark KC 85 / 1.11: 1940 Mark KC 87 / 1.10: 3005 Mark ( IAP ) KC 87 / 1.11: 3390 Mark (IAP) |
| processor | UA880D @ 2.5 MHz |
| random access memory | 16 KB, upgradeable to 64 KB |
| graphic | Text mode plus 128 graphic symbols for pseudographs, full graphics optional |
| Sound | Buzzer |
| Disk | Plug-in modules , compact cassettes |
| operating system | Z9001-OS (Version 1.1–1.3) Optional: SCP (CP / M 2.2) |
| predecessor | - |
| successor | A 5105 |
The Robotron Z 9001 is a home computer based on the U880 microprocessor from VEB Robotron from the German Democratic Republic .
The desk-shaped computer was developed from 1983 initially to supply private households, but also for use in educational institutions. The state requirements provided for the lowest possible production costs using components exclusively produced in the Comecon countries. The first devices came on the market at the end of 1984, supplemented by separately purchased expansion modules such as RAM add-ons and various programming languages that could initially only be loaded from a compact cassette .
Planning specifications that had been changed in the meantime shifted the focus of use of the device, now known as the “small computer”, to educational institutions and production. In addition to minor technical revisions, this was also taken into account by renaming it to Robotron KC 85/1 .
Additional improvements for more efficient production and the incorporation of the BASIC programming language finally led to a further downward-compatible generation of devices in 1987 . The new name Robotron KC 87 , based on the year, also served to identify the incompatibility with the competing computer models KC 85/2, KC 85/3 and KC 85/4 from VEB Mikroelektronik from Mühlhausen . With the start of production of the official successor model, the educational computer A 5105 , production of the KC 87 was stopped in the spring of 1989.
A total of around 30,000 units of the Z 9001, KC 85/1 and KC 87 were delivered.
history
In the time of the Cold War were the CMEA -Staaten access and imports of high technology, including first computer technology in general, and later microelectronics specifically counted by the CoCom denied largely embargo. The existing demand was quickly met by developing illegally procured technology using reverse engineering . Thanks to this and other efforts, the GDR had its own large-scale electronic computing technology developed in-house in the form of the Robotron 300 from the late 1960s . The first microprocessor manufactured in the GDR, a replica of the Intel 8008 , which was already five years old at the time , was added with the U808 in autumn 1977.
Framework
In order to satisfy the demand for computers, which had also arisen in the education and private sectors from the beginning of the 1980s, the government decided to expand development and production activities to include consumer goods. In contrast to already existing entertainment electronics such as the screen game device BSS 01 , which has been produced since 1980, and the SC 2 chess computer, which has been available since 1982 , the new developments should above all offer the possibility of programming by the user.
Employees of established electronics manufacturers such as the Dresden VEB Robotron and the Mühlhäuser VEB Mikroelektronik are already working on feasibility studies for home computers. That is why they took up the state directives for the implementation of such a prestige object only too willingly. For example, VEB Robotron's “decentralized data technology product range”, which is characterized by industry, was expanded to include corresponding capacities within a very short time from the end of 1982. The “Realization concept for home computers based on the U 880” started only a little later in January 1983 in the in-house center for research and technology in Dresden. At the same time, those in charge of the VEB Mikroelektronik in Mühlhausen also took the opportunity and launched a similar youth project called "Video Computer", which was independent of Dresden's efforts. This uncoordinated approach by both companies caused resentment even in the highest political circles due to the competitive situation it caused, which was not welcome in the GDR planned economy . In the end, however, both projects remained unchanged, presumably on the assumption that one manufacturer alone would not be able to meet the huge demand for home computers in the GDR. The home computer to be developed by both institutions should, following the instructions of the Ministry of Electrical Engineering and Electronics , be affordable and robust with compact dimensions.
Development specifications
The state planning requirements for the mostly young engineers and employees of the corresponding developer group ("youth researcher collective") from the Center for Research and Technology of the VEB Robotron in Dresden provided for an expandable compact device with an integrated keyboard and the lowest possible material and manufacturing costs. The home electronics usually found in private households in the GDR, such as televisions and cassette recorders, had to be usable by the computer.
In order to keep the production processes as efficient as possible, the simplest components and groups should be used in production. Due to the CoCom embargo, integrated circuits exclusively from GDR or RGW production had to be used in the design. The tight specifications regarding the low production costs with the simultaneously required robustness in everyday use could only be implemented with a system architecture based on the inexpensive and field-tested 8-bit U880 microprocessor and standardized electronic circuit components. High-resolution raster graphics ("full graphics") and connections for special peripheral devices fell victim to cost pressure and the lack of space in the material-saving and therefore small-sized housing. The conception of the computer as a modular system with expansion bays (“ bus expansion interface ”), however, envisaged simple retrofitting. The proposals developed in the Center for Research and Technology were checked from mid-1983 onwards using prototypes in the Dresden factory VEB Robotron-Meßelektronik, the later manufacturer.
Prototypes
The first three functionally identical prototypes with the internal name SHAFY based on the name of an employee were released on July 1st (model 01/83) , on September 9th (model 02/83) and on September 16, 1983 (model 03/83) completed. These partially preserved patterns are based on hand-wired breadboard boards with 2 kilobytes (KB) of working memory , 4 KB of read-only memory in addition to CP / M -oriented system software , character generator and a full-fledged typewriter keyboard . The 01/83 and 03/83 models were used to develop software and for extensive tests in order to avoid costly complaints and repairs in the future. The 02/83 model was mainly used for demonstration purposes.
After all tests were successful and production seemed economically efficient, series production was planned from the end of 1983. The project called “Development, transfer and production of the home computer Z 9001” was also supported by the political side (“initiative topic” of the SED ) and promoted by providing additional employees from the FDJ . Bureaucratic obstacles were removed so that the process could be completed after eleven months. One of the few prototype components that fell victim to cost optimization for series production was the typewriter keyboard. It has been replaced by an inexpensive elastomer mat, which is also used in smaller dimensions in pocket calculators. In addition, the capacity of the working memory to be installed ex works has been increased from 2 to 16 KB, among other things by means of cheaper memory modules that have since appeared.
During the entire development period, the engineers of the computer projects in Dresden and in Mühlhausen agreed and implemented common standards for easy software exchange between their two home computer systems. This primarily concerned the use of one and the same BASIC interpreter as well as a standardized recording process for the cassette recorder to be connected.
The computer ready for series production, henceforth called Z 9001, was - like the competitor product HC 900 from Mühlhausen, which has meanwhile been completed - presented to the world public with great attention at the international spring fair in Leipzig .
Z 9001
Since private households and educational institutions in the GDR in the mid-1980s were not equipped with color televisions across the board, the Z 9001 appeared in two versions. The cheaper basic models with the designation Z 9001.10 only had a black and white version, the Z 9001.11 series had a color version. The black-and-white devices could be converted to color output by specialist workshops using an upgrade kit available later.
The computers were manufactured in several production areas. The fully assembled printed circuit boards supplied by the Robotron branch in Riesa were assembled, tested and delivered in Radebeul (Plant I) and Pockau (Plant II) with the housings and keyboards manufactured there to form the end product. The software included with the computer on compact cassette and the additional software that can be ordered separately was provided by VEB Deutsche Schallplatten (Amiga).
The first series went into production on the occasion of the 35th anniversary of the founding of the GDR in September 1984. Of these, only about 50 copies went on the free market. The remaining of the first 100 devices produced by December 1984 were delivered to the student computer center in Dresden and to the Heinrich Hertz special school in Berlin. From 1985 the devices were delivered with a slightly revised printed circuit board (Series 85) and production numbers increased. The range of memory expansion modules available from the computer market launch has been expanded to include printer interfaces and an improved, external graphics module.
KC 85/1
Government decisions in 1985 shifted the focus of the use of computers developed for private use to the fields of education and business. Consequently, it was renamed the home computer Z 9001 in small computer Robotron KC 85/1 (short KC 85/1 ), the Mühlhäuser competitor HC 900 was renamed KC 85/2 . The technically largely unchanged KC-85/1 devices were presented for the first time at the Leipzig spring fair and from March 1985 they were produced in large numbers and delivered to educational institutions. There is no compatibility with the similarly named but much more expensive device KC 85/2 from the manufacturer VEB Mikroelektronik Mühlhausen, despite the common BASIC dialect and data storage format.
With the Z 9001 and KC 85/1, the BASIC programming language was not contained in the computer's read-only memory, but had to be loaded from the cassette into the main memory. As a result, in the basic version without memory expansion, only about 5 KB of working memory were available after loading, which considerably restricted the computer's possible uses. The necessary further development for the joint integration of the operating system and BASIC in the read-only memory and the associated revision of the circuit board began in September 1985 with the "Z 9002" project.
KC 87
After various technical improvements introduced in 1985 as part of the “Z 9002” project, the device, which was updated until 1987, was renamed the Robotron KC 87 small computer due to the large scope of changes . The number used in the device name indicates the planned start of production in 1987. The first samples were already available to the public in 1986 at trade fairs in Dresden and Leipzig. Until the development work was completed in March 1987, mainly pre-series models (KC 87.10 and KC 87.11) were produced and primarily used for development, test and demonstration purposes.
Regular series production began in April 1987. The variants KC 87.20 and KC 87.21 have the configuration options of the built-in BASIC for controlling the separately available full graphics module or corresponding plotter . All devices produced in 1987 were intended exclusively for educational institutions and companies. From 1988 onwards, some of the 8,000 computers produced annually were sold for the first time in regular retail stores to supply the population. The delivery took place in RFT specialist branches and center department stores via previously stored "customer requirements lists ". For a better differentiation, the devices intended for distribution to “social consumers” such as educational institutions and companies were given the model designation KC 87.30 and KC 87.31. Production of the KC 87 was phased out in March 1989 in favor of the Robotron A 5105 educational computer ( BIC A 5105 for short ). A total of around 30,000 units of the Z 9001, KC 85/1 and KC 87 were delivered.
| Model name | Screen output | particularities | Price (year) |
|---|---|---|---|
| Z 9001.10 | black-and-white | BASIC must be loaded from a cassette or cartridge | EVP 1550 M (1985) |
| Z 9001.11 | coloured | EVP 1940 M (1985) | |
| KC 85 / 1.10 | black-and-white | BASIC must be loaded from a cassette or cartridge | EVP 1550 M (1985) |
| KC 85 / 1.11 | coloured | EVP 1940 M (1985) | |
| KC 87.10 | black-and-white | BASIC in ROM | IAP 3005 M (1987) |
| KC 87.11 | coloured | IAP 3390 M (1987) | |
| KC 87.20 | black-and-white | BASIC in ROM, prepared for full graphic commands | unknown |
| KC 87.21 | coloured | unknown | |
| KC 87.30 | black-and-white | like KC 87.20, probably only for business | unknown |
| KC 87.31 | coloured | like KC 87.21, probably only for business | EVP 3300 M (1988) |
Technical details
The basic units each contain the electronic components computer unit with main processor (English Central Processing Unit for short CPU ), storage unit with working and read-only memory, keyboard, screen control, peripheral connections and power supply. The computers have four module slots ( parallel bus ), whereby the power consumption of inserted modules was taken into account when dimensioning the computer power supply. In addition to the basic device, the scope of delivery included a program cassette , a power cord, a power fuse, an antenna cable or RGB cable for connecting a television set and the documentation consisting of the operating instructions, programming manual and an appendix to the programming manual.
Inside the housing of the KC 85/1
KC 87 with revised circuit board
Main processor
The system architecture is based on a U880 microprocessor clocked at 2.5 MHz , which was used in almost all contemporary GDR computers. This unauthorized replica of the Z80 microprocessor from Zilog can access an address space of 65,536 bytes , which also defines the theoretically possible upper limit of the main memory of 64 kilobytes (KB). For practical reasons, it is common for addresses instead of decimal notation , the hexadecimal to use. This is usually preceded by a $ symbol to make it easier to distinguish. The addresses from 0 to 65,535 in decimal notation correspond to addresses $ 0000 to $ FFFF in the hexadecimal system.
Storage and storage allocation
The address space that can be used by the main processor is divided into areas for the operating system, main memory, read-only memory, expansions and graphics memory for all devices.
The 4 KB operating system Z9001-OS , based on CP / M -80, is located in the top memory area from $ F000 to $ FFFF. In the Z 9001 it is housed in two EPROM modules, in the KC 87 it is in one ROM module. To store system variables, the operating system uses the lowest area, from $ 0000 to $ 021F, of the 16 KB working memory ex works.
About 15 KB of RAM from $ 0220 to $ 3FFF are freely available to the user. When using the maximum possible two RAM expansion modules of 16 KB each in the memory segment from $ 4000 to $ BFFF, the capacity of the usable main memory increases to 47 KB. With the Z 9001 and KC 85/1, for programming with BASIC, the approximately 10 KB programming language must be loaded from the cassette into the RAM memory from $ 0300 to $ 3FFF. Without RAM expansion, only 5 KB of RAM are available for your own programs. If, on the other hand, the BASIC is provided by a plug-in module, there remains around 15 KB of usable memory.
In the case of the KC 87, the BASIC interpreter can already be found ex works in the read-only memory (ROM) of the computer and in the case of the Z 9001 and KC 85/1 with the ROM module plugged in, it can be found under the addresses $ C000 to $ E7FF. The image memory required for displaying text ranges from $ EC00 to $ EFFF for the Z 9001 and KC 85/1; in the case of color output, it is supplemented by a corresponding color memory in the range from $ E800 to $ EBFF.
Graphics and sound generation
In the basic configuration, the computers only have a character generator with a text mode of either 40 × 20 or 40 × 24 characters with 8 × 8 pixels each. The non-changeable character set provides 128 alphanumeric and control characters as well as 128 graphic symbols for so-called quasi-graphics. According to the manufacturer, the use of the graphic symbols allows a representation that is sufficient for many applications. A high-resolution raster graphics mode ("full graphics") is not available, but can be retrofitted externally. The black and white image output of the basic versions KC 87.10, KC 87.20 and KC 87.30 takes place via the coaxial HF antenna connection on a standard television set . The variants KC 87.11, KC 87.21 and KC 87.31 with a “color card” installed ex works enable the display of eight foreground and eight background colors via an RGB connection .
The two input and output circuits contained in the computers with the model number U855 (English Parallel Input Output for short PIO ) enable the operation of the keyboard and the use of joysticks ("game levers"), the control of the cassette recorder and a programmable sound generation (unison, mono ). The sound is output either via the loudspeaker built into the computer or an external amplifier.
Interfaces for input and output
To connect peripherals, the computers have various interfaces that are controlled by the built-in U855 or U857 (English Counter Timer Circuit, short CTC ). These include the socket with digital input and output channels for special applications and a joystick connection with a five-pin DIN socket for the joysticks produced by Robotron. There are also slots in the module slot for up to four extensions.
Periphery
Mass storage
In connection with mainly western home computers of the 1980s, cassette recorders and floppy disk drives were mainly used as mass storage devices, and hard and removable disk drives were increasingly used in the professional environment for personal computers. The cheapest variant of data recording using audio cassettes has the disadvantage of low data transfer rates and thus long loading times, whereas the much faster and more reliable floppy and disk drives were much more expensive to purchase or, in the case of the GDR, hardly available. When the Z 9001 appeared, only cassette recorders and tape systems were available for data recording . Disk systems were only added some time after the publication of the KC 87 at the end of 1988 and only in small series.
Cassette systems
All Robotron small computers have a connection for storing programs and data on compact cassettes using commercially available cassette recorders. Devices with smaller dimensions, such as the Geracord , Datacord and later LCR-C DATA from the manufacturer VEB Elektronik Gera, were offered for sale specifically for use with computers . The average data transfer rate through the interface is around 1,000 bit / s. 300 to 360 KB of data can be stored on a double-sided, 60-minute audio cassette.
Floppy disk systems
Towards the end of 1988 a diskette system developed by the Central Institute for Nuclear Research in Rossendorf near Dresden was presented to the public for the KC-Computer . The system includes various components for connection to the computer and an add-on device which may contain two 5¼-inch drive mechanisms , for example of the type K5601 diskette memory . The connection to the computer is via a plug-in module that contains all the control electronics and a 26-pin cable for connecting to the diskette device. It allows the operation of a maximum of two drives with storage capacities of up to 800 KB per diskette.
The CP / M-compatible SCP was supplied as a floppy operating system, which requires a work memory of 64 KB. By switching the memory bank (“shadow RAM”), SCP enables variable system data to be temporarily stored, which leads to a reduced number of mechanical diskette accesses and thus to shorter loading times.
keyboard
The integrated alphanumeric elastomer keyboard contains 65 keys in a typewriter-like QWERTZ arrangement . Due to the small, stiff and not ergonomically shaped buttons and the lack of pressure point, it is hardly suitable for longer work and has been replaced by more comfortable versions by many users, especially in the industrial sector. Two control light-emitting diodes (LED) are embedded in the keypad ; the red LED on the right-hand side lights up after the computer is switched on, the green LED on the left-hand side shows that the keys have been switched to special characters. The keyboard was often felt to be very unergonomic and, for example, replaced by typewriter keyboards on our own initiative.
Extensions
The computers supplied only offer a minimum amount of hardware. Independent operation is thus possible, but many tasks require an upgrade. Apart from the kit for converting the basic computer variants to color output, almost all available extensions are connected to the expansion slot. A total of four slots are available for the corresponding expansion modules. Due to incompatibilities between some extensions, the four slots cannot be used at the same time in all cases.
Only the most important and frequently used expansion modules are described in more detail below. This is followed by a tabular listing of all extensions produced by Robotron with a brief description of their functions.
Memory upgrades
Various expansion modules, including those produced by Robotron, are available to increase the working memory. With the appearance of the Z 9001, due to the high production costs, the selection was limited to those with a storage capacity of only 16 KB RAM and battery-buffered versions with even less, namely only 4 KB, but static RAMs ("SRAM"). The main purpose of the SRAM was to temporarily store variable data, which should still be available after the computer was switched off, for example due to a power failure. After removing the SRAM module from the slot, the data it contains can be transferred to other computers even after several weeks of storage. From 1989 an improved SRAM module with a storage capacity of 10 KB was available. When using memory expansions, the user must manually assign an address range to be assigned (either from $ 4000 to $ 7FFF or from $ 8000 to $ BFFF) using DIP switches .
In addition, there are other RAM modules with higher storage capacity from third-party manufacturers or hobbyists, which only appeared after the prices fell towards the end of 1988. The Rossendorf floppy disk system, for example, contains a RAM module with a storage capacity of 64 KB.
Expansion to full graphics
This extension supplements the display options of the computer with a high-resolution monochrome pixel graphics mode with 256 × 192 pixels ("full graphics"). The assembly consists of the electronics built into an external housing with RGB image signal generation and its own video memory as well as a ribbon cable for connection to one of the four expansion slots. The assembly chassis is constructed in such a way that the computer to be placed on it cannot slip due to the corresponding retaining pins. A mechanical switch enables either the full graphics or the character set modes of the computer to be displayed on the connected image output device. An additional 32 KB RAM in the form of two 16 KB RAM modules and driver programs supplied on a cassette are required for operation. Use with computers other than the KC 87.20 and 87.21 also requires the plotter module, which enables the pixel graphics to be controlled using BASIC commands. If the assembly is to be operated with the non-color-capable computer variants, a few modifications must be made to the extension.
Connection of printers, plotters and external keyboards
The computers do not have any options for controlling a printer at the factory. Rather, depending on the type of printer, either driver programs have to be loaded or appropriate expansion modules have to be retrofitted. There are additions for the operation of the 9- pin printer produced by the Sömmerda office machine factory with the designations K6303 , K6311 and K6312 or for the K6304 thermal printer . An extension was also available for operating the Czechoslovakian plotters of the types XY4131 and XY4141 available in the GDR . This plotter module also supplements the BASIC standard command set of the KC 87.10 and KC 87.11 computers and, after minor adjustments, that of the Z 9001 and KC 85/1 with corresponding full graphic commands.
Many electronic typewriters , which are widespread in the GDR and equipped with a type wheel printing mechanism , have the option of being able to print externally fed data. They have therefore often been used as inexpensive output systems, particularly for home computer systems. The supported typewriters include the series S3000 , Erika 3004 , Erika 3005 , Erika 3006 , Erika 3015 and Erika 3016 from the manufacturer VEB Robotron Optima Büromaschinenwerk Erfurt as well as the model Erika 6005 from VEB Mikroelektronik Erfurt. When the typewriter module is used, these devices can also be used as a convenient replacement keyboard for the computer.
Others
In addition to being used in education, computers were often used for automation in production due to the lack of alternatives. The applications were limited to simple control tasks, for example in greenhouses or in robotics . The physical quantities to be controlled, such as temperature and pressure, must be converted into a form that can be processed by the computer before the evaluation. This means that the analog signal from the sensor must be converted into a digital one. The analog-digital converter extension ("ADC module") required for this was often used together with the input-output module ("I / O module") to control external actuators , for example . In addition, computers with ADC modules also served as digital oscilloscopes, that is, to visualize measured variables that change over time.
| Type designation | function | description | price |
|---|---|---|---|
| 1.40.690003.5 | Memory expansion | 16 KB RAM | EVP 618 M |
| 2-4002 | 4 KB of SRAM | Unknown | |
| Unknown | 10 KB SRAM | Unknown | |
| 1.40.690002.7 | 10 KB ROM | Unknown | |
| 1.40.690001.0 | programming language | BASIC | EVP 785 M. |
| 1.40.690020.3 | IDAS (assembler plug-in module) | EVP 755 M. | |
| 1.40.690026.0 | Editor / assembler | EVP 368 M | |
| 1.40.690025.2 | Printer interface | Matrix printer K6311 or K6312 | IAP 422 M. |
| 1.40.690006.8 | Thermal printer K6303 | IAP 422 M. | |
| 1.40.690021.1 | Typewriter interface | S6005 | EVP 685 M |
| 1.40.690023.6 | EPROM burner | 2K EPROMs type U2716C | EVP 368 M |
| 1.40.690009.2 | Analog-digital conversion | Digitization of up to four DC voltages in the range from −99 to +999 mV | EVP 662 M |
| 1.40.690010.7 | Input / output | U855-based interface with 16 ports | EVP 400 M |
| 1.40.690032.4 | Voice input | Digitization and speech recognition | EVP 343 M. |
| 1.40.690033.2 | Plotter interface | For the plotter XY4130 or the full graphics module. | EVP 174 M. |
| 1.40.690016.4 | Color addition | Supplementary set color (for TV) | Unknown |
| 1.40.690005.1 | Color expansion | For installation in the computer | EVP 186 M |
| 1.40.690007.6 | Game lever addition | 1 or 2 game levers | Unknown or EVP 125 M |
| 1.40.690007.7 | Game lever adapter | Adapter for connecting two joysticks to computers with color output | Unknown |
| 1.40.690017.2 | adapter | Adapter for connection to the user port | EVP 68 M |
software
The existing software is mainly in-house developments from the GDR. Implementations of programs from western Z80-based home computer systems were usually very complex due to technical differences and were only carried out by the ZX80 and ZX81 computers, which were also very limited in their graphic capabilities . The higher programming languages created for the Z 9001 and KC 87 were also not compatible with those of western systems, as the instruction set was largely optimized for the peculiarities of the GDR computers. The easiest way to exchange programs and adapt the software accordingly is with the computers of the KC 85/2 to KC 85/4 series, which have a similar system architecture and have the same data storage format and BASIC dialect. For special tasks it was often more economical to develop corresponding software from scratch.
As with other home computers, software was distributed on various data carriers. The inexpensive compact cassettes were very prone to errors due to the high mechanical stress on the magnetic tape and their use was often associated with long loading times. In the case of the ROM modules, which are much more expensive to manufacture, the programs contained therein were available immediately after switching on the computer, which was a great advantage in particular with system software and frequently used applications such as programming languages. In addition to the modules supplied with built-in software, there is also a ROM module that can be freely equipped (type designation 690 002.7). There is space for up to five EPROMs of 2 KB each on the sockets, which were previously often provided with data using the EPROM programming device also available from Robotron.
The dissemination of software and the exchange of experiences took place primarily through private contacts and through newspaper advertisements , at trade fairs, through the printing of programs in magazines and through broadcasting on the radio , such as in the program Rem . The creation of software was promoted by the state, for example through the Society for Sport and Technology (GST) with its computer sports section . Their activities also included the organization and staging of public competitions, the “programming Olympiads”.
There were no restrictions on disclosure through copyright protection and the associated copy protection mechanisms . Retail sales only played a role, albeit a subordinate one, for the programs developed by Robotron. A commercial software offer comparable to the home computer market in Western Europe or North America did not exist for application software or in the games area.
System programs
The Z9001-OS operating system contained in the read-only memory is used to configure the computer hardware, in slightly different versions depending on the type of computer. It is based on the CP / M-80 operating system presented by Digital Research 1974 for Intel 8080 and Zilog Z80 reference systems . It differs from the original in some modifications made by Robotron engineers, such as the implementation of the cassette interface and the changed memory allocation.
A specially adapted version of CP / M 2.2 with the name SCP was made available in 1988 to operate the Rossendorf diskette system, which can be operated together with the Z9001-OS. Its internal structure and scope of commands essentially correspond to that of CP / M. This extensive compatibility means that the extensive CP / M-based program library is also available for the computer. Many of these programs such as B. WordStar cannot run due to the limited graphic and keyboard options of Z 9001 or KC 87, others such as Turbo Pascal require appropriate modifications for proper operation. Another advantage of SCP is the included printer drivers, which enable the user port to be used as a software printer interface. This eliminates the need to use a printer module, which means that one slot in the expansion slot, which is almost completely occupied by the diskette system, remains free for additional peripherals. In addition to the actual system software, the SCP data carrier also contains the compatible ZBASIC, which has been expanded to include diskette access commands .
Programming languages
Building on the system software, the user-specific use of computers in a wide variety of application areas, such as in educational institutions, but also in business, was of great importance. Due to the practically non-existent software market in the GDR, initially almost all subject areas had to be covered by software that was developed in-house or had to be adapted. For the Z-9001 and KC-85/1 computers, only the BASIC and assembly language to be loaded from the cassette were available at the time of publication. Further high-level programming languages were added later, with the advent of the Rossendorf diskette system, powerful CP / M-based compiler languages such as Turbo Pascal.
Assembly language
The inadequate equipment of the computers, the processing of time-critical problems ("real-time applications") or the integration of hardware developed in-house and therefore not supported as standard required in many cases memory-efficient and hardware-related programming. With U880-based devices, this was only possible through the use of assembly language with appropriate translation programs, the assemblers . The editor, which is often supplied, is used to enter the program instructions ("source code"). Debuggers that are also available simplify error analysis.
Initially, only the uncomfortable SYPS- K-1520 editor / assembler (EDAS) was available on a program cassette with the type designation R0121 or 690 026.0 or as a plug-in module. The Interpretative Dialog Assembler (IDAS), which was added later when the KC 87 was released , not only allowed the usual assembly of the entire source code in one piece, but also - like an interpreter - line-by-line processing. In assembler programming, which is otherwise difficult to master, this technique is of great advantage, particularly for efficient error diagnosis. IDAS was also delivered with the associated editor and a machine language monitor on a compact cassette with the type designation R0122 or as a plug-in module. For the use of IDAS with Z 9001 and KC 85/1, minor changes had to be made to the circuit board of the plug-in module.
Less time-critical and hardware-related applications could be programmed with the much clearer and easier-to-use, but slower and less flexible high-level languages.
Interpreter high-level languages
With the appearance of the Z 9001, an adapted version of the K-1520 -BASIC was also available. This BASIC variant, developed by the Agricultural Institute in Dummerstorf , is based on the Extended Microsoft BASIC , which was published for western computers in the late 1970s .
After the computer was started, the programming language first had to be read from a cassette into the 16 KB RAM, which was already sparse, which meant that the possibilities of use were limited to smaller programming projects. Later, the BASIC was also offered as a plug-in module, which, in conjunction with the maximum possible memory upgrade, also enabled more extensive programming tasks to be carried out, for example in production use.
The international BASICODE project developed by Dutch radio , which aimed to standardize the BASIC dialects of various home computers, was also reflected in a corresponding additional program for Robotron's KC computers.
Compiler high-level languages
In addition to the beginner-friendly BASIC, more sophisticated compiler-based high-level programming languages such as KC-Pascal (as a PASMOD plug-in module), Pretty C and Forth were also available in the area of software development . The advantages of these languages lie in the speed of the executable programs they create, but at the cost of increased hardware requirements. Applications created with Pretty C, for example, achieve up to 30 times higher execution speeds for certain special cases than comparable programs in BASIC, but also require - at the time costly - upgrades of the main memory to at least 32 KB.
If the user had a floppy disk system with a CP / M-compatible SCP operating system, a large number of CP / M-based programming languages such as ZBASIC or Turbo Pascal could be used after various modifications .
Applications and games
The manufacturer Robotron primarily offered simple games and programs for the educational sector and distributed them through VEB Robotron-Vertrieb Berlin, Dept. VD. With Script , a word processor that was very extensive in terms of functionality was available for the time . A large number of adaptations and portings of classic arcade games such as Centipede , Mazogs , Tetris , Pac-Man and Boulder Dash , but also of well-known board and card games such as chess , skat , poker and Monopoly, were made by hobby programmers in particular .
Magazines
There were no special magazines for the KC 87 or for all small GDR computers. The magazines Funkamateur , Jugend + Technik , MP Mikroprocessortechnik and Practic regularly published news, reports, handicraft instructions for self-construction of additional hardware or upgrading and converting computers and programs for typing.
Even after German reunification , the exchange of interests within the supporters of GDR computing technology in private publications and, from the late 1990s, also in Internet forums was maintained. The best known is the quarterly magazine KC-News of the KC-Club founded in 1991 . The club's website offers a contact point for problems and questions about the computers of the KC series, which can be deepened at the annual meetings that have taken place across Germany since 1995.
emulation
After the end of the home computer era in the early 1990s and with the emergence of powerful and affordable computing technology in the mid-1990s, dedicated enthusiasts increasingly developed programs for emulating home computers and their peripherals. To play old classics from a wide variety of home computer systems, a single modern system with data images of the corresponding home computer programs is sufficient with the aid of the emulators. The emergence of the emulators set in motion, among other things, an increased transfer of otherwise possibly lost software to modern storage media, which makes an important contribution to the preservation of digital culture.
The KCemu , which runs under Windows and Linux, was developed to emulate Z 9001, KC 85/1 and KC 87 . The JKCemu represents a further development and is able to emulate almost all computers from the GDR era.
reception
Contemporary
When the computers were first presented at the Leipzig spring fair in 1984, both the HC 900 and Z 9001 met with great interest. The positive reception by the trade fair audience was reflected shortly afterwards in euphoric newspaper reports. State-controlled magazines such as Jugend + Technik and Funkamateur celebrated the Z 9001 as an expandable "high-performance data processing system" for "controlling devices for home and hobby technology", as a "freely programmable acquisition, processing and control center for test and demonstration arrangements" and as a Requirement for "versatile screen games for creative entertainment".
After the KC 87 was presented a few years later, the GDR press characterized the computer much more soberly as "good for introducing practically all sections of the population to problems in the application of computer technology" and as being versatile in its use as "simple modifiability for various tasks using plug-in modules" the limitations of the storage space and the computing speed are of course limited ”.
From the western side, the technology of the devices presented at the Leipzig spring fair in 1984 was judged somewhat more cautiously and was more concerned with economic aspects based on surveys of interested trade fair visitors. In these interviews, visitors from the GDR consistently rated the computer as difficult to obtain and too expensive; a future spread in private households was doubted.
Retrospective
More recently, the computers developed and produced in the GDR, including in particular small computers and video game machines, have been increasingly noticed again in the media, above all on the Internet, and are also exhibited in special museums. Z 9001, KC 85/1, KC 87 and the Mühlhausen computers KC 85/2 to 85/4 are characterized as completely in-house developments, although many individual electronic components such as the U880 microprocessor and the system software are copies of Western models how the Z80 microprocessor from Zilog acts with its CP / M operating system. In addition, the designers of the GDR computers are certified technical and planning foresight. Despite “complicated economic conditions” and “specific material conditions”, the devices are technically reliable and easy to control by the user, which “was received with great enthusiasm by young people in particular and used very creatively.” At the same time, there is no doubt that the The technological lag of computers compared to the products of western industrialized countries at the time of their publication was always about three to five years: When production of the KC 85/1 started in the GDR, much more powerful computers for private households were already available in western countries. In direct comparison to the western Z80-based computers such as the Sinclair ZX Spectrum , most GDR small computers are at least equivalent in terms of “range of applications, processing power and connection options”. However, these possibilities could not have been fully exploited due to “peripherals that are seldom available for sale, unsuitable keyboard ergonomics, sometimes a lack of graphics capability and limited software”. The end of production for small computers in the GDR, which was briefly sealed after the fall of the Wall, is unanimously attributed to the lack of competitiveness due to the hardware and software lag that cannot be made up.
literature
- Klaus-Dieter Weise: Product line home computers, small computers and educational computers of the VEB Kombinat Robotron. UAG Historie Robotron of the computer technology working group in the Technical Collections Dresden , Dresden 2005, (PDF; 391 KB).
Web links
- KC-Club An association of KC-85 users with the aim of disseminating information about the KC 85 and coordinating current developments around this computer system
- KCemu An emulator for current Windows and Linux systems
- JKCemu A Java based emulator that emulates almost all computer systems of the GDR.
- robotron - history (s) and technology On the website of the Friends' Association for the Technical Collections of the City of Dresden e. V.
- Extensive documentation and circuit diagrams on the website of a former Robotron employee
- Small computers from Dresden In a virtual computer museum about the development of computing technology in the GDR
Notes and individual references
- ↑ a b Jugend + Technik , No. 8, August 1984, p. 587.
- ↑ a b c d e Robotron information brochure: Sales units of the small computer KC 85/1 u. KC 87. Retrieved February 8, 2014.
- ↑ Ulrich Zander: Home computer Z9001, KC85 / 1 and KC87 programs - operating system. Retrieved February 8, 2014.
- ↑ Weise, p. 14.
- ↑ a b Weise, p. 23.
- ↑ Weise, p. 22.
- ↑ Jugend + Technik, No. 5, 1984, pp. 329–333.
- ^ Peter Salomon: The history of the microelectronic semiconductor industry in the GDR. Funkverlag Bernhard Hein e. K., 2003, ISBN 3-936124-31-0 , p. 90.
- ↑ Weise, p. 24.
- ↑ a b c d Weise, p. 28.
- ↑ Weise, p. 27.
- ↑ Weise, p. 29.
- ↑ Ulrich Zander: Home computers Z9001, KC85 / 1 and KC87 - historical. Retrieved February 8, 2014.
- ↑ Weise, p. 12 ff.
- ↑ Weise, p. 31.
- ↑ a b c Weise, p. 30.
- ↑ a b Computerwoche : Electronics combines show user solutions - first home computers in the GDR. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. April 6, 1984 issue; Jugend + Technik, No. 5, 1984, p. 330 ff.
- ↑ a b Weise, p. 32.
- ↑ Weise, p. 36.
- ↑ a b Volker Pohlers: Homecomputer DDR - graphics add-on. Retrieved February 8, 2014.
- ↑ Weise, p. 43.
- ↑ a b Weise, p. 44.
- ↑ Weise, p. 44 f.
- ↑ Weise, p. 37.
- ↑ a b c d e f g MP microprocessor technology : Robotron KC 87 - the new small computer at a glance. VEB Verlag Technik, Issue 1, 1987.
- ↑ VEB Robotron measuring electronics "Otto Schön" Dresden: small computer robotron KC 87 operating instructions. P. 5.
- ↑ Weise, p. 8.
- ^ VEB Robotron measuring electronics "Otto Schön" Dresden: Small computer Robotron KC 85/1 - Appendix to the programming manual. P. 8 f.
- ↑ Color television sets available in the GDR had to be retrofitted with a standard kit for operation via RGB.
- ↑ A conversion of the connection on the joystick or the self-construction of a corresponding adapter for the use of joysticks from western manufacturers with a nine-pin D-Sub connector is possible.
- ↑ VEB Robotron measuring electronics "Otto Schön" Dresden: small computer robotron KC 87 operating instructions. P. 9 f.
- ↑ VEB Robotron measuring electronics "Otto Schön" Dresden: small computer robotron KC 87 operating instructions. P. 9 and p. 19.
- ↑ a b c VEB Robotron measurement electronics "Otto Schön" Dresden: Disk station for the KC 85/1 and KC 87.
- ↑ a b F. Schwarzenberg: CP / M 2.2 on KC 85/1 and KC 87.Retrieved on October 20, 2016.
- ↑ VEB Robotron measuring electronics "Otto Schön" Dresden: small computer robotron KC 87 operating instructions. P. 13.
- ↑ VEB Robotron measuring electronics "Otto Schön" Dresden: small computer robotron KC 87 operating instructions. P. 20.
- ↑ VEB Robotron measuring electronics "Otto Schön" Dresden: 10k byte SRAM extension module for Z9001 / KC87. Retrieved February 8, 2014.
- ↑ VEB Robotron-Meßelektronik "Otto Schön" Dresden: Operating documentation SRAM-4-KB extension module 2-4002. Retrieved February 8, 2014; Microprocessor technology, VEB Verlag Technik, Issue 8, 1988, p. 248.
- ↑ VEB Robotron-Meßelektronik "Otto Schön" Dresden: Operating instructions graphic addendum 690 035.7. 1984, p. 1 ff.
- ↑ Volker Pohlers: Homecomputer DDR - plotter. Retrieved February 8, 2014.
- ↑ Erika-Elektronic: Typewriter module for the home computer Z 9001, KC 85/1 and KC 87. Retrieved on February 8, 2014.
- ↑ Jugend + Technik, No. 8, 1984, p. 587.
- ^ Robotrontechnik.de: Small computer from Dresden. Retrieved February 8, 2014.
- ↑ LOAD magazine: Computer in the GDR. Association for the Preservation of Classic Computers V., Issue 2, 2013, p. 16.
- ↑ Dresden Library: Chronicle of the years 1954 - 1990. Retrieved on October 20, 2016.
- ↑ VEB Robotron measuring electronics "Otto Schön" Dresden: small computer robotron KC 87 operating instructions. P. 15 f.
- ↑ Chip: Commodore 64 A cult computer turns 30. 2012, p. 24.
- ↑ a b Login Magazin, Datalog Software AG Munich, Edition 2, 2004, p. 8.
- ^ MP Microprocessor Technology, VEB Verlag Technik, Issue 2, 1988, p. 62; Tom Schnabel: Small computers in the GDR - computer championships in the GDR. Diploma thesis, Institute for Computer Science, Department "Computer Science and Society" at the Humboldt University of Berlin, 1999.
- ↑ Pirated Copies - Legally Free Playground. Spiegel Online, January 29, 1990. Retrieved February 12, 2018.
- ↑ Bernd Schindler: Heimcomputer Z 9001. rfe 1984, issue 3, p. 148 f .; VEB Robotron measuring electronics "Otto Schön" Dresden: Operating system KC 85/1 (Z 9001). P. 3.
- ↑ MP Mikroprocessortechnik , VEB Verlag Technik, Issue 10, 1987, p. 311 ff.
- ↑ VEB Robotron-Meßelektronik "Otto Schön" Dresden: Editor / assembler for the home computer Robotron Z 9001. Retrieved on October 20, 2016.
- ↑ For example, macro definitions are not possible.
- ↑ VEB Robotron measuring electronics "Otto Schön" Dresden: Description of IDAS module 690 020.3. Retrieved October 20, 2016.
- ↑ a b Jürgen Lübcke, Reinhard Villbrandt: BASIC interpreter for K1520. Radio Fernsehen Elektronik, Verlag Technik Berlin, Issue 1, 1982, pp. 14-16.
- ↑ MP Microprocessor Technology, VEB Verlag Technik, Issue 6, 1988, p. 174.
- ^ Website of the KC Club . Retrieved February 8, 2014; Load magazine, Association for the Preservation of Classic Computers e. V., Issue 2, 2013, p. 16 f.
- ↑ Andreas Lange: What archives, museums and libraries can learn from gamers - and vice versa. Retrieved February 23, 2014.
- ^ Load magazine, Association for the Preservation of Classic Computers V., Issue 2, 2013, p. 17.
- ↑ Website of the developer of JKCemu
- ↑ The computer game museum in Berlin shows in its permanent exhibition, for example, a video game machine from GDR production.
- ↑ Chip: Commodore 64 Ein Kult-Computer wird 30 , 2012, p. 24; Weise, p. 12 f.
- ↑ Tom Schnabel: Small computers in the GDR - final consideration. Diploma thesis, Institute for Computer Science, Department "Computer Science and Society" at the Humboldt University of Berlin, 1999.
- ↑ a b Weise, p. 17; Axel Salheiser: Loyal to the party, according to plan , professional? VS Verlag für Sozialwissenschaften, 1st edition, 2009, ISBN 978-3-531-16943-9 , p. 102.
- ^ Load magazine, Association for the Preservation of Classic Computers V., Issue 2, 2013, p. 11.
