This article needs additional citations for verification . (July 2009) (Learn how and when to remove this template message)
Main board of Galaksija during assembly process
|CPU||Zilog Z80A @ 3.072 MHz|
|Memory||2–6KB RAM, 4–8KB ROM|
The Galaksija (Cyrillic: Галаксија; [galǎksija] , meaning "Galaxy") was a build-it-yourself computer designed by Voja Antonić. It was featured in the special edition Računari u vašoj kući (Computers in your home, written by Dejan Ristanović) of a popular eponymous science magazine, published late December 1983 in Belgrade, Yugoslavia. Kits were available but not required as it could be built entirely out of standard off-the-shelf parts. It was later also available in complete form.
In the early eighties, various laws in SFR Yugoslavia prevented importing computers into the country. At the same time, even the cheapest computers available in the West were nearing average monthly salaries. This meant that regardless of demand for home computers, only a relative minority of people owned one – mostly a ZX Spectrum or a Commodore 64.
According to his own words,some time in 1983, Voja Antonić, while vacationing in Hotel Teuta in Risan, was reading the application handbook for the RCA CDP1802 CPU and stumbled upon CPU-assisted video generation. Since the CDP1802 was very primitive, he decided that a Zilog Z80 processor could perform the task as well.
Before he returned home to Belgrade, he already had the conceptual diagrams of a computer that used software to generate a video picture. Although using software as opposed to hardware would significantly reduce his design's performance, it also simplified the hardware and reduced its cost.
His next step was to find a magazine to publish the diagrams in. The obvious choice was SAM Magazine published in Zagreb, but due to prior bad experiences he decided to publish elsewhere.
The popular science magazine Galaksija appeared incompatible but he heard that they were working on a special issue dedicated to computers. He proposed publishing entire do-it-yourself diagrams, instructions, etc. to the author of the issue, Dejan Ristanović. Everything made its way into the special issue called Računari u vašoj kući (Computers in your home). It was released late December 1983, although it was dated January 1984.
They tried to guess the number of Galaksijas that would be built by readers. Their estimates ranged from a hundred to a thousand (a number that sounded so optimistic it provoked laughter). The actual number built by known "do-it-yourselfers" – was around 8000!This number may in reality be greater if people who did not purchase any kits (including PCB and ROMs) are accounted for.
Components were provided by various manufacturers and suppliers:
Later, Institute for school books and teaching aids together with Elektronika Inženjering started mass commercial production of Galaksija computers, mainly to be delivered to schools.
Galaksija BASIC is a BASIC interpreter originally partly based on code taken from TRS-80 Level 1 BASIC, which the creator believed to have been a Microsoft BASIC.However, after extensive modifications to include video generation code (as the CPU was a major participant to reduce the cost of hardware) and improve the programming language, what remained from the original is said to be mainly flow-control and floating point code. It was fully contained in 4 KB ROM "A" or "1". Additional ROM "B" or "2" provided more Galaksija BASIC commands, assembler, monitor, etc.
The chip labeled as "A" by the creator of Galaksija, Voja Antonić was commonly referred to as "ROM 1" or just "ROM". ROM "A" contained bootstrap code of Galaksija, its control code (rudimentary operating system), video generation code (as Galaksija did not have advanced video subsystem its Z80 CPU was responsible even for generating video signal) and Galaksija BASIC.
Fitting all this functionality in 4 KB of 2732 EPROM required a lot of effort and some sacrifices. For example, some message text areas were also used actual code (e.g. "READY" message) and the number of error messages was reduced to only three ("WHAT?", "HOW?" and "SORRY").
ROM "B" of the Galaksija is a 2732 EPROM chip that contains extensions to the original Galaksija BASIC available in base ROM ("A"). It was labeled as "B" by the creator of the Galaksija, Voja Antonić, but was commonly referred to as "ROM 2".
ROM "B" contained added Galaksija BASIC commands and functions (mostly trigonometric) as well as a Z80 assembler and a machine code monitor. This ROM was not required and was an optional upgrade. Although planned on the mainboard, the content of ROM "B" was not automatically initialized during booting. Instead, users had to execute a Galaksija BASIC command to run a machine code program from ROM "B" before they can gain additional features. This also meant that even Galaksijas with ROM "B" plugged in can behave entirely as base models.
Character ROM of home computer Galaksija is a 2716 EPROM chip that contains graphical definitions of Galaksija's character set. It had no special name and was labeled "2716" after the type of 2 KB EPROM needed.
Galaksija had a slightly modified (localized) ASCII character set:
Each character was represented as 8x13 matrix of pixels. In this ROM, 8-pixel rows of each character are represented as 8 bits of one byte.
Galaksija used cassette tape as secondary storage. It featured a 5-pin DIN connector used to connect the computer to a cassette tape recorder. Tape interface circuitry was rudimentary – other than few elements controlling the levels it was essentially one-bit digital equivalent to the one in the ZX Spectrum. The input signal was routed to the integrated circuit otherwise responsible for keyboard, so the CPU would "see" the input signal as a series of very fast key presses of varying lengths and gaps between them.
It is normally stated that original Galaksija does not have any dedicated (separate) audio ports and most of the programs were written as silent. It was, however, possible to utilize the cassette tape port as an audio output as well like it is done in ZX Spectrum (its "EAR" connector). The only technical difference between ZX Spectrum and Galaksija in regards to existence of audio is that ZX Spectrum has a built-in beeper, while Galaksija's plans do not include any kind of a speaker.
To simplify "do-it-yourself" building and reduce cost, the printed circuit board was designed as single-layer (one-side) board. This resulted in a relatively complicated design requiring many components-side connections to be made using wires.
Galaksija's case was not pre-built. Instead, the guide suggested it to be built out of the printed circuit board material (such as Pertinax) also used for the mainboard. Thus, the top, sides and reinforcements were soldered together to form the "lid". Acrylic glass was recommended for the underside. The guide included instructions on cleaning, painting and even decorating the assembled case. The name "GALAKSIJA" and decorative border were to be added using Letraset transfer letter sheets after the first (white) coat of paint but before the second coat of final colour. After the paint dried, transferred decorations were supposed to be scratched off, exposing underlying white paint.
The keyboard is laid out such that keys have their own memory-mapped addresses that, in most cases, follow the same order as ASCII code of the letter on the key. This saved the ROM space by reducing lookup tables but significantly increased the complexity of single-layer keyboard PCB such that it alone required 35 jumpers.
The Amstrad CPC is a series of 8-bit home computers produced by Amstrad between 1984 and 1990. It was designed to compete in the mid-1980s home computer market dominated by the Commodore 64 and the Sinclair ZX Spectrum, where it successfully established itself primarily in the United Kingdom, France, Spain, and the German-speaking parts of Europe.
The Jupiter Ace by Jupiter Cantab was a British home computer of the early 1980s. The Ace differed from other microcomputers of the time in that its programming environment used Forth instead of the more popular BASIC.
The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research.
The Nascom 1 and 2 were single-board computer kits issued in the United Kingdom in 1977 and 1979, respectively, based on the Zilog Z80 and including a keyboard and video interface, a serial port that could be used to store data on a tape cassette using the Kansas City standard, and two 8-bit parallel ports. At that time, including a full keyboard and video display interface was uncommon, as most microcomputer kits were then delivered with only a hexadecimal keypad and seven-segment display. To minimize cost, the buyer had to assemble a Nascom by hand-soldering about 3,000 joints on the single circuit board.
The Enterprise is a Zilog Z80-based home computer announced in 1983, but through a series of delays, not commercially available until 1985. The specification as released was powerful and one of the higher end in its class. This was due to the use of ASICs for graphics and sound which took workload away from the CPU, an extensive implementation of ANSII BASIC and a bank switching system to allow for larger amounts of RAM than the Z80 natively supported. It also featured a distinctive and colourful case design, and promise of multiple expansion options. Ultimately it was not commercially successful, after multiple renames, delays and a changing market place. Its manufacturer calling in the receivers in 1986 with significant debt. It was developed by British company Intelligent Software and marketed by Enterprise Computers. Its two variants are the Enterprise 64, with 64 kilobytes of Random Access Memory (RAM), and the Enterprise 128, with 128 KB of RAM.
MicroBee was a series of networkable home computers by Applied Technology, which became publicly listed company MicroBee Systems Limited soon after its release.
The Tangerine Microtan 65 is a 6502 based single board microcomputer, first sold in 1979, which could be expanded into, what was for its day, a comprehensive and powerful system. The design became the basis for what later became the ORIC ATMOS and later computers, which has similar keyboard addressing and tape I/O as in the Microtan 65. The Microtan 65 has a single step function that can be used for debugging at the hardware level. The computer was available as ready-built boards or as kits consisting of board and components requiring soldering together.
Vojislav "Voja" Antonić is a Serbian inventor, journalist and writer. He was also a magazine editor and contributed to a number of radio shows but he is best known for creating a build-it-yourself home computer Galaksija and originating a related "Build your own computer Galaksija" initiative with Dejan Ristanović. This initiative encouraged and enlightened thousands of computer enthusiasts during the 1980s in the Socialist Federal Republic of Yugoslavia. Mr. Antonić donated many of his personally creations to the public domain, whenever they related to the common people or a fellow engineer.
Dejan Ristanović, is a well known Serbian writer and computer publicist.
Galaksija Plus was an improved version of Galaksija, with 256x208 monochrome graphics mode, 3-voice sound based on AY-3-8910 and 48 KiB RAM.
Galaksija BASIC was the BASIC interpreter of the Galaksija build-it-yourself home computer from Yugoslavia. While being partially based on code taken from TRS-80 Level 1 BASIC, which the creator believed to have been a Microsoft BASIC, the extensive modifications of Galaksija BASIC—such as to include rudimentary array support, video generation code and generally improvements to the programming language—is said to have left not much more than flow-control and floating point code remaining from the original.
Ventilator 202 was a live radio show broadcast by Beograd 202 radio station during the 1980s and hosted by Zoran Modli. It was one of the most important shows of Belgrade's "202" station and possibly also the most important project of its host. It first aired first June 3, 1979. Zoran Modli was its host until late 1987. He later hosted another similar show, Modulacije. "Ventilator 202" was renamed to "501" and hosted by Dubravka Marković, giving it her own style. It was notable for its promotion of local (domestic) demo music, early application of computers and introduction of "absolute radio" concept.
The Socialist Federal Republic of Yugoslavia (SFRY) was a socialist country that existed in the second half of the 20th century. Being socialist meant that strict technology import rules and regulations shaped the development of computer history in the country, unlike in the Western world. However, since it was a non-aligned country, it had no ties to the Soviet Bloc either. One of the major ideas contributing to the development of any technology in SFRY was the apparent need to be independent of foreign suppliers for spare parts, fueling domestic computer development.
The SAPI-1 was a computer produced in the former Czechoslovakia by Tesla since 1980.
Vector-06C is a home computer with unique graphics capabilities that was designed and mass-produced in USSR in the late 1980s.
The Dick Smith Super-80 was a Zilog Z80 based kit computer developed as a joint venture between Electronics Australia magazine and Dick Smith Electronics. It was presented as a series of construction articles in Electronics Australia magazine's August, September and October 1981 issues.
The British Broadcasting Corporation Microcomputer System, or BBC Micro, is a series of microcomputers and associated peripherals designed and built by the Acorn Computer company in the 1980s for the BBC Computer Literacy Project, operated by the British Broadcasting Corporation. Designed with an emphasis on education, it was notable for its ruggedness, expandability, and the quality of its operating system. An accompanying 1982 television series, The Computer Programme, featuring Chris Serle learning to use the machine, was broadcast on BBC2.
The MRB Z1013 was an East German Single-board computer produced by VEB Robotron Riesa which was primarily intended for private use and educational institutions. It was powered by a U880 processor and sold together with a membrane keyboard. Initially, the kit was equipped with 16-KByte DRAM, which was later replaced by a 64-KByte version.
Each time Intel launched a new microprocessor, they simultaneously provided a System Development Kit (SDK) allowing engineers, university students, and others to familiarise themselves with the new processor's concepts and features. The SDK single-board computers allowed the user to enter object code from a keyboard or upload it through a communication port, and then test run the code. The SDK boards provided a system monitor ROM to operate the keyboard and other interfaces. Kits varied in their specific features but generally offered optional memory and interface configurations, a serial terminal link, audio cassette storage, and EPROM program memory. Intel's Intellec development system could download code to the SDK boards.
The TC 3256 or Timex Computer 3256 was a computer created by Timex of Portugal, a branch of Timex Corporation.
|Wikimedia Commons has media related to Galaksija .|