Enterprise 128
Encyclopedia
The Enterprise is a Zilog Z80
based home computer
first released in 1985. There are two variants, the Enterprise 64 with 64 kB
of RAM, and the Enterprise 128 with 128 kB.
running at 4 MHz, 64 kB or 128 kB of RAM, and 32 kB of internal ROM containing the EXOS operating system and a screen editor / word processor. BASIC was supplied on a 16 kB ROM module.
Memory is expandable up to 4 MB using bank switching scheme. The 64 kB address space of the Z80 processor is divided into four 16k sections. One of the 256 16k memory pages can be mapped individually into each of the sections. The top four pages (64 kB) are used as video RAM, but it is possible to store program code and data there, too. The system ROM is mapped on the lowest two pages. The next four pages were reserved for ROM cartridge (max 64 kB).
Two ASIC
(aka ULA) chips take some of the workload off the central processor. They are called "Nick" and "Dave", named after their designers: Nick Toop, who had previously worked on the Acorn Atom
, and Dave Woodfield.
Nick handles graphics, while Dave handles sound and memory paging.
. Its overall shape was also notably distinctive compared to the more conservative designs of the time, the designers stating that they wanted break away from the norm. The keyboard is low profile and ergonomic, with standard keyboard layout, but the feel of the keys did receive some negative reviews. It is constructed with a rubber membrane, on top of which the mechanical keycaps are installed. (This is pretty much how low-cost PC keyboards are constructed these days.) The joystick which replaces the normal cursor keys allows moving cursor even in diagonal directions. The product design firm hired by Robert Madge to design and engineer the case and keyboard was Hollington Associates, a London-based consultancy. Geoff Hollington and Nick Oakley, both graduates of the Royal College of Art, were responsible for the design.
), and attribute graphics. On top of this, 2, 4,16 or 256 colours can be selected in bit mapped graphics modes, but more colours gives lower horizontal resolution. Interlaced or non-interlaced mode can be used. The highest resolution is 640×512 pixels interlaced or 640×256 pixels non-interlaced, but this only allows 2 colours. With 256 colours, the maximum resolution is 80×256. The attribute graphics mode gives 320×256 pixel resolution with 16 colours selectable from palette of 256.
Multiple pages can be displayed on screen simultaneously, even pages with different graphics modes. Each page has its own palette, thus allowing more colours to be displayed on screen simultaneously. The height of the page can be larger than the screen or the window it is displayed on. Each page is connected to a channel of the EXOS operating system, so it is possible to write even on a hidden page.
In addition, the chip has programmable envelope generators that are more flexible than the traditional ADSR envelope. Up to 255 phases can be specified for each envelope. On each phase, the envelope can slide the sound pitch and left/right volume a given amount in the given time.
printer port, two external joystick ports, two cassette interfaces, a ROM cartridge
slot and an ordinary expansion port. To save money, however, many of the connectors on the rear did not come with sockets but instead had simple edge connector
s using the exposed traces on the edge of the printed circuit board
.
The BASIC ROM can even be replaced by a ROM which can emulate a ZX Spectrum
, thus in theory allowing the Enterprise to run the existing catalogue of thousands of Spectrum games. Later, an external floppy drive became available, supporting CP/M
programs.
In addition, the system ROM contains a full screen editor, which doubles as simple word processor. It can be used to edit BASIC programs or any other language programs or other text files. The editor takes advantage of the joystick for cursor control.
's BBC Micro
had a similar system.
IS-Basic quite strictly follows the ANSI
BASIC standard. It is a fully structured language with wide set of control structures. These include multi-line IF...THEN...ELSE, SELECT...CASE, DO...LOOP with WHILE and UNTIL conditions at the begin and/or end of the loop and EXIT LOOP statement. Procedures and functions can have both reference and value parameters and local variables. Errors and other exceptions are handled with exception handlers.
A unique feature of IS-Basic is the ability to have multiple programs simultaneously in memory. Each program has a separate set of global variables and line numbers, but it is possible to call one program from another and pass parameters with the CHAIN statement.
Graphics, sound and I/O ports can be controlled directly from BASIC, so there is a rarely need for POKE and PEEK statements.
IS-Basic has the usual commands for drawing dots, lines, circles and ellipses and for filling areas. In addition, Logo
-style turtle graphics
can be used. Sound commands can be entered into a queue and executed in the background while the program execution continues.
compatible operating system opened access to the wide range of CP/M programs that were available at that time.
in 1982, a Hong Kong
trading company called Locumals decided to commission Intelligent Software in the UK to develop a home computer. The head of Intelligent Software was David Levy, an international chess
player.
During development the machine had the codename DPC, standing for damp-proof course, to throw off potential competitors in case anyone left the development plans on a bus. The machine was also known by the names Samurai, Oscar, Elan and Flan before the Enterprise name was finally chosen.
Emulating Amstrad
's AMSOFT
, Entersoft was set up to ensure a steady supply of software for the new machine.
Although the machine was announced to the press in September 1983, it did not go on sale until April 1984, at which point some 80,000 machines were pre-ordered. Unfortunately machines did not ship until 1985, by which point the competitive environment was much worse for Enterprise, as the UK home computer market had become dominated by the ZX Spectrum, Commodore 64, Amstrad CPC and Acorn BBC Micro.
A successor machine, the PW360, was developed in 1986 to compete directly against the Amstrad PCW
8256, but by this time the company was in severe financial difficulties and went under.
After the initial manufacturing run of 80,000 units it is not believed that any further units were made, making the Enterprise an extraordinarily collectible item in Europe. When Enterprise (the company) was wound up in Europe, 20,000 units were shipped to Hungary where it appears a strong user community formed.
Zilog Z80
The Zilog Z80 is an 8-bit microprocessor designed by Zilog and sold from July 1976 onwards. It was widely used both in desktop and embedded computer designs as well as for military purposes...
based home computer
Home computer
Home computers were a class of microcomputers entering the market in 1977, and becoming increasingly common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user...
first released in 1985. There are two variants, the Enterprise 64 with 64 kB
Kilobyte
The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...
of RAM, and the Enterprise 128 with 128 kB.
Hardware
CPU, memory and ASIC chips
The machine has a Z80 CPUCentral processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
running at 4 MHz, 64 kB or 128 kB of RAM, and 32 kB of internal ROM containing the EXOS operating system and a screen editor / word processor. BASIC was supplied on a 16 kB ROM module.
Memory is expandable up to 4 MB using bank switching scheme. The 64 kB address space of the Z80 processor is divided into four 16k sections. One of the 256 16k memory pages can be mapped individually into each of the sections. The top four pages (64 kB) are used as video RAM, but it is possible to store program code and data there, too. The system ROM is mapped on the lowest two pages. The next four pages were reserved for ROM cartridge (max 64 kB).
Two ASIC
ASIC
ASIC may refer to:* Application-specific integrated circuit, an integrated circuit developed for a particular use, as opposed to a customised general-purpose device.* ASIC programming language, a dialect of BASIC...
(aka ULA) chips take some of the workload off the central processor. They are called "Nick" and "Dave", named after their designers: Nick Toop, who had previously worked on the Acorn Atom
Acorn Atom
The Acorn Atom was a home computer made by Acorn Computers Ltd from 1980 to 1982 when it was replaced by the BBC Micro and later the Acorn Electron....
, and Dave Woodfield.
Nick handles graphics, while Dave handles sound and memory paging.
Keyboard and case
The case is unique for its time, at least in the UK, for containing both a full-sized keyboard with programmable function keys and a joystickJoystick
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or...
. Its overall shape was also notably distinctive compared to the more conservative designs of the time, the designers stating that they wanted break away from the norm. The keyboard is low profile and ergonomic, with standard keyboard layout, but the feel of the keys did receive some negative reviews. It is constructed with a rubber membrane, on top of which the mechanical keycaps are installed. (This is pretty much how low-cost PC keyboards are constructed these days.) The joystick which replaces the normal cursor keys allows moving cursor even in diagonal directions. The product design firm hired by Robert Madge to design and engineer the case and keyboard was Hollington Associates, a London-based consultancy. Geoff Hollington and Nick Oakley, both graduates of the Royal College of Art, were responsible for the design.
Graphics
Enterprise has 5 graphics modes: 40 and 80 column text modes, Lo-Res and Hi-Res graphics (bit mappedRaster graphics
In computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
), and attribute graphics. On top of this, 2, 4,16 or 256 colours can be selected in bit mapped graphics modes, but more colours gives lower horizontal resolution. Interlaced or non-interlaced mode can be used. The highest resolution is 640×512 pixels interlaced or 640×256 pixels non-interlaced, but this only allows 2 colours. With 256 colours, the maximum resolution is 80×256. The attribute graphics mode gives 320×256 pixel resolution with 16 colours selectable from palette of 256.
Multiple pages can be displayed on screen simultaneously, even pages with different graphics modes. Each page has its own palette, thus allowing more colours to be displayed on screen simultaneously. The height of the page can be larger than the screen or the window it is displayed on. Each page is connected to a channel of the EXOS operating system, so it is possible to write even on a hidden page.
Sound
The sound is handled by the second ASIC chip, Dave. It has 3 sound channels plus a noise channel, in stereo. The sound from each channel can be freely placed (left-right) in the stereo image. Distortion, low-pass and high-pass filters and ring modulation can be used.In addition, the chip has programmable envelope generators that are more flexible than the traditional ADSR envelope. Up to 255 phases can be specified for each envelope. On each phase, the envelope can slide the sound pitch and left/right volume a given amount in the given time.
Interfaces
The machine came with a surprising array of connectors, far beyond what was common on home computers of the time. There is an RGB output, RS232 / RS423 serial port, a CentronicsCentronics
Centronics Data Computer Corporation was a pioneering American manufacturer of computer printers, now remembered primarily for the parallel interface that bears its name.-The beginning:Centronics began as a division of Wang Laboratories...
printer port, two external joystick ports, two cassette interfaces, a ROM cartridge
ROM cartridge
A ROM cartridge, sometimes referred to as a cart, is a removable enclosure containing read-only memory devices designed to be connected to a computer or games console....
slot and an ordinary expansion port. To save money, however, many of the connectors on the rear did not come with sockets but instead had simple edge connector
Edge connector
An edge connector is the portion of a printed circuit board consisting of traces leading to the edge of the board that are intended to plug into a matching socket. The edge connector is a money-saving device because it only requires a single discrete female connector , and they also tend to be...
s using the exposed traces on the edge of the printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
.
The BASIC ROM can even be replaced by a ROM which can emulate a ZX Spectrum
ZX Spectrum
The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research Ltd...
, thus in theory allowing the Enterprise to run the existing catalogue of thousands of Spectrum games. Later, an external floppy drive became available, supporting CP/M
CP/M
CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
programs.
System ROM
EXOS (Enterprise Expandable Operating System) on the system ROM is based on channels. All devices, such as display, keyboard, printer, tape and disk interfaces are accessed using channels. This allows the programs to treat all input and output devices in an identical fashion.In addition, the system ROM contains a full screen editor, which doubles as simple word processor. It can be used to edit BASIC programs or any other language programs or other text files. The editor takes advantage of the joystick for cursor control.
IS-Basic
Unlike most other home computers of the time, Enterprise does not have BASIC or any other programming language in the internal ROM. Instead, the BASIC interpreter was supplied on a 16k ROM cartridge, so the language can be changed just by switching the cartridge. AcornAcorn
The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...
's BBC Micro
BBC Micro
The BBC Microcomputer System, or BBC Micro, was a series of microcomputers and associated peripherals designed and built by Acorn Computers for the BBC Computer Literacy Project, operated by the British Broadcasting Corporation...
had a similar system.
IS-Basic quite strictly follows the ANSI
Ansi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....
BASIC standard. It is a fully structured language with wide set of control structures. These include multi-line IF...THEN...ELSE, SELECT...CASE, DO...LOOP with WHILE and UNTIL conditions at the begin and/or end of the loop and EXIT LOOP statement. Procedures and functions can have both reference and value parameters and local variables. Errors and other exceptions are handled with exception handlers.
A unique feature of IS-Basic is the ability to have multiple programs simultaneously in memory. Each program has a separate set of global variables and line numbers, but it is possible to call one program from another and pass parameters with the CHAIN statement.
Graphics, sound and I/O ports can be controlled directly from BASIC, so there is a rarely need for POKE and PEEK statements.
IS-Basic has the usual commands for drawing dots, lines, circles and ellipses and for filling areas. In addition, Logo
Logo
A logo is a graphic mark or emblem commonly used by commercial enterprises, organizations and even individuals to aid and promote instant public recognition...
-style turtle graphics
Turtle graphics
Turtle graphics is a term in computer graphics for a method of programming vector graphics using a relative cursor upon a Cartesian plane...
can be used. Sound commands can be entered into a queue and executed in the background while the program execution continues.
Other software
In addition to IS-Basic, several other languages (Forth, Lisp, Pascal, Assembler) were available either on ROM cartridge or on tape. Basic-to-Basic converters could be used to convert BASIC programs from other home computers. Some 40 games were listed in the catalog, from IS and other publishers. IS-DOS, the CP/MCP/M
CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
compatible operating system opened access to the wide range of CP/M programs that were available at that time.
Development
After the home computer market in the UK took off with the launch of the Sinclair ZX SpectrumZX Spectrum
The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research Ltd...
in 1982, a Hong Kong
Hong Kong
Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...
trading company called Locumals decided to commission Intelligent Software in the UK to develop a home computer. The head of Intelligent Software was David Levy, an international chess
Chess
Chess is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. It is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.Each player...
player.
During development the machine had the codename DPC, standing for damp-proof course, to throw off potential competitors in case anyone left the development plans on a bus. The machine was also known by the names Samurai, Oscar, Elan and Flan before the Enterprise name was finally chosen.
Emulating Amstrad
Amstrad
Amstrad is a British electronics company, now wholly owned by BSkyB. As of 2006, Amstrad's main business is manufacturing Sky Digital interactive boxes....
's AMSOFT
Amsoft
Amsoft was a wholly owned subsidiary of Amstrad, PLC, founded in 1984 and re-integrated with its parent company in 1989. Its purpose was to provide an initial infrastructure of software and services for users of Amstrad's range of home computers, the Amstrad CPC and, from 1986, the Sinclair ZX...
, Entersoft was set up to ensure a steady supply of software for the new machine.
Although the machine was announced to the press in September 1983, it did not go on sale until April 1984, at which point some 80,000 machines were pre-ordered. Unfortunately machines did not ship until 1985, by which point the competitive environment was much worse for Enterprise, as the UK home computer market had become dominated by the ZX Spectrum, Commodore 64, Amstrad CPC and Acorn BBC Micro.
A successor machine, the PW360, was developed in 1986 to compete directly against the Amstrad PCW
Amstrad PCW
The Amstrad PCW series was a range of personal computers produced by British company Amstrad from 1985 to 1998, and also sold under licence in Europe as the "Joyce" by the German electronics company Schneider in the early years of the series' life. When it was launched, the cost of a PCW system was...
8256, but by this time the company was in severe financial difficulties and went under.
Commercial failure
Despite being particularly powerful for the time, the machine was not a commercial success. The Amstrad CPC 464 was released before the Enterprise; it included a monitor and cassette recorder and retailed for less.After the initial manufacturing run of 80,000 units it is not believed that any further units were made, making the Enterprise an extraordinarily collectible item in Europe. When Enterprise (the company) was wound up in Europe, 20,000 units were shipped to Hungary where it appears a strong user community formed.
Enterprise emulators for PC
External links
- Enterprise Forever forum
- Hungarian page about Enterprise
- Hungarian Enterprise forum
- The German version was apparently called Mephisto PHC 64
- e64 revisited - a game-oriented history of the Enterprise