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A '''Speccy Port''' or '''Spectrum port''' is the name given to a game which has been converted directly from the Sinclair Spectrum with little or no changes to the Amstrad CPC. Often the Amstrad version ended up fairing worse than the original Spectrum version (though some games actually ended up pretty decent).
Mostly the Amstrad version ended up fairing worse than the original Spectrum version with the following results:
- Less colours
- Slower gameplay
These facts are not true for all "Spectrum Ports" because some ended up decent.
=Reasons=
The [[ZX Spectrum]] shared the same CPU as similar hardware with the Amstrad CPC and had a simple graphics display. Given that the Spectrum was very popular with the CPC having a much smaller market share, to save on time and money (a typical Spectrum port to the Amstrad is said to have been done in 3 dayssee Machine comparions), the Spectrum code was re-used.
The Amstrad screen Spectrum was reduced in size very popular with the CPC having a much smaller market share, so to match the Spectrum's save on time and often most of the colour was removed. Most spectrum ports were done in [[Video modes|Video Mode 1]] (4 colour mode)money, because the resolution of this mode matched the resolution of the Spectrumcode, music and this allowed graphics were re-used. A typical port to the use of the same graphicsAmstrad is said to have been done in 3 days so was financially good.
Most of them got their graphic totally unchanged, displaying some kind of colour attributes "artifacts", a tell-tale sign of a Speccy port.
This phenomenon was more prominent in the UK, where the Speccy was the dominant machine. In other markets, such as France of Spain, where the CPC was very popular, games were coded from scratch for the CPC, often using an [[Atari|Atari ST]] for [[Games Crossdev|Cross Development]]
== Machine comparisons ==
Spectrum and Amstrad both have a Z80 CPU.
Spectrum and Amstrad both have a bitmapped display.
The Amstrad's screen can be reduced in size to match the Spectrum's (256x192). Normal display size on Amstrad is 320x200.
Spectrum (128K model and later) and Amstrad both have an AY-3-8912 sound chip.
The Spectrum's bitmapped display is comparable to Amstrad's mode 1 bitmapped display.
The Spectrum's video ram takes approx 6K. The Amstrad's video ram takes 16K (approx 12K when screen is reduced).
The Spectrum 48k can't do double buffering in hardware, the Amstrad can. (To fix this problem on Spectrum they stored a bitmap in ram which they drew to, and then wrote changes to the screen).
The Spectrum has a fixed palette of 16 colours (8 colours with 8 bright versions).
The Spectrum's screen is "attribute" based. Each 8x8 cell can be assigned a background and foreground colour. The Amstrad's screen doesn't have this restriction, 4 colours can be chosen from a palette of 27, and can be placed as you choose.
The Spectrum has 1 interrupt per 50Hz frame, the Amstrad has 6 in fixed locations.
===Consequences===
