Enterprise

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pictures courtesy from S.Walgenbach.


The Enterprise 64 and Enterprise 128 computers were a range of Z80 based machines, who were quite influancial on the design of the Amstrad CPC.


Informations

Wikipedia's Article :

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. The machine was also known by the names DPC, Samurai, Oscar, Elan and Flan before the Enterprise name was finally chosen[1].

The machine has a Z80 CPU running at 4 MHz,[2] 64 kB or 128 kB of RAM and 48 kB of ROM containing the EXOS operating system and BASIC. The case is unique for its time, at least in the UK, for containing both a full-sized membrane keyboard with programmable function keys and a joystick. 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 although this did tend to polarise opinions in the computing press.

The machine was specifically engineered for games, with display resolutions up to 672×512 pixels and up to 256 colours per pixel, one byte per pixel being particularly easy to program, though full colour capabilities were limited to its 80×180 pixel mode. Sound was 4 channels, stereo. Coprocessors for graphics and sound take some of the workload off the central processor, called "Nick" and "Dave" respectively, named after their designers: Nick Toop, who had previously worked on the Acorn Atom, and Dave Woodfield.

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/RS432 serial port, a Centronics printer port, two external joystick ports, two cassette interfaces, a ROM cartridge slot and an ordinary expansion port. To save money, however, the connectors on the rear did not come with sockets but instead had simple edge connectors 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.

Development

After the home computer market in the UK took off with the launch of the Sinclair ZX Spectrum 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.

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.

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.

Hardware

The Enterprise has custom video and sound hardware.

Video Chip

The video chip is called "Nick" and it executes a display list. This allows the mode to be redefined every scanline. The Enterprise has a variety of bitmap modes, ranging from cell based bitmap modes similar to the Spectrum, to bitmapped modes like the CPC. It also supports hardware text mode, and 256 colors (8 levels of red * 8 levels of green * 4 levels of blue).

Therefore converting graphics and code from either platform was fairly easy, although mode 0 of the CPC was made somewhat more difficult by the fact that only the first 8 colors of the palette can be chosen freely, while the second 8 colors are generated by using the lower 3 bits of the color index as the most significant bit of the red, green, and blue components, and the remaining 5 bits are added from a "fixbias" register. For this reason, a 16-color CPC conversion usually needs to find a good "fixbias" value, and convert all pixel data to the changed order of colors in the Enterprise palette. In the case of Spectrum conversions, it was also necessary to convert the attribute data.

Soundchip

The sound chip is called "Dave" and has 3 channels of sound (square wave or noise), and a fourth channel that can only generate noise; it also has 6-bit stereo volume control for all channels, simple (digital) filters, ring modulation, various noise waveforms, has a selection of interrupts and can play samples easily.

Basically, all this make approximately the same capability as a ZX spectrum128, combining an AY-3-8910 and a beeper.

Games

The computer didn't receive many official games. Most games were ported from Spectrum or the Amstrad by fans on the Enterprise. The Enterprise has a big following in Hungary.

As a Z80 based computer with good and flexible graphic capabilities, the port of Amstrad CPC Games was achievable on Enterprise, as evidenced by the following videos.

Batman, clearly a CPC port.

Airwolf, also a CPC port. Yet not a clever choice indeed.

Sorcery, another game ported from CPC.

Rick Dangerous 2, recently ported from the CPC.


The fact the Enterprise 64/128 could mix Character attribute system or Amstrad like bitmap Graphic modes, with a greater freedom, means it could easily benefit from both Softwares Library with a bit of hacking.

As evidenced there and here, other CPC games were ported on Enterprise :

  • Alien Attack
  • ATF
  • Barbarian
  • Castle Master
  • Castle Master 2
  • Commando
  • Crystal Kingdom Dizzy
  • Cybernoid
  • Cybernoid 2
  • Dark Side
  • Deflektor
  • Donkey Kong
  • Driller
  • Exolon
  • Head over Heels
  • H.E.R.O.
  • Hydrofool
  • Impossible Mission
  • Impossible Mission II
  • Krakout
  • Nebulus
  • Pinball Power (3D Pinball)
  • Prince of Persia
  • Rick Dangerous
  • Rick Dangerous 2
  • Sorcery
  • Sorcery+
  • Super Hero
  • Total Eclipse
  • Total Eclipse 2
  • WEC Le Mans

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