Difference between revisions of "Plus"

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(Demos with Plus features)
m (GX4000)
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* Console manual
* Console manual
* Game manual
* Game manual
* Power supply
* Power supply 11v 500mA - -(o- +
* Optional: [[Amstrad MM12 Monochrome Monitor]] or [[Amstrad CM14 Colour Monitor]]
* Optional: [[Amstrad MM12 Monochrome Monitor]] or [[Amstrad CM14 Colour Monitor]]
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== Emulators for CPC Plus ==
== Emulators for CPC Plus ==

Revision as of 14:48, 27 July 2010


In 1990 Amstrad introduced the "Plus" series which tweaked the hardware in many ways and added a cartridge slot to all models. Most improvements were to the video display which saw an increase in palette to 4096 colours and gained the capability of hardware sprites. Splitting the display into two separate windows and pixel scrolling both became full supported hardware features although both were possible on the non-"Plus" hardware using clever programming of the existing Motorola 6845.

An automatic DMA transfer system for feeding the sound chip was also added but the sound chip itself remained unchanged. Additionally, the BASIC command set for disc access was improved.

A cut down CPC+ without the keyboard nor support for non-cartridge media was released simultaneously as the GX4000 video game console.

These models did not do very well in the marketplace, failing to attract any substantial third party support. The 8-bit technology behind the CPC was starting to look a little out of date by 1990 and users resented the substantial price hike for cartridge games compared to their tape and disc counterparts. It's often forgotten that Europe had a large CPC following well supplied by Amstrad it's said the plus machines sold best in France.

(Taken from Wikipedia.org)


For details about the CPC+/GX4000 features, see Arnold V Specs Revised.

The CPC Plus

CPC Plus can use cartridges released for the GX4000, but specific software can be created using the extra features without the need of hardware (contrary as it was claimed by Amstrad in 1991). The extra features are not locked by a hardware mechanism but only by a special 17 bytes-lenght sequence send to the CRTC. So, it's possible for everyone to create his/her own software on the cpc plus, using the extra features available through a 16kb ASIC I/O page(See Programming ASIC.) Except the extra-features, the 464 & 6218 Plus machines are almost fully compatible with the old CPC generation. Some minor differences are noticable in emulated components (PPI, CRTC, Gate ArrayGate Array) and in the interrupt mechanism in vectorised mode.

The GX4000 Games Console

The GX4000 is a game console based on a CPC 464+ without a floppy controller or keyboard (although it is actually possible to modify one, add a floppy controller and a keyboard and use it as a CPC+). It was delivered with two game paddles (as the ones delivered with the CPC+ models) and Burning Rubber on cartidge (without basic).

The GX4000 was Amstrad's attempt to gain some share in the home game console market, then dominated by the likes of Nintendo and Sega. Like others before it, and like others after it, it failed abysmally in its goal. Despite the fact that the hardware was decent (after all the CPC+ series were some of the very best 8-bit computers ever designed), it was a case of 'too little, too late'. Lack of CPC+ specific software, lack of marketing effort and bad timing meant that Amstrad's adventure in the home market was about to end.

GX4000 Differences compared to 464 or 6128 Plus

  • The master clock is 39.9Mhz (approx) instead of 40Mhz for the 464/6128 Plus. The Arnold V specification indicates this is to give a better picture. This means the GX4000 is 0.25% slower than a 464 or 6128 Plus but should have a better picture.
  • The pause button on the GX4000 is mapped to the P button on the CPC keyboard. Other than this the 2 digital joysticks are connected, all other keys are not connected.
  • There is a difference in the wiring schematics on the ADC inputs where the ASIC senses the computer configuration.
  • The following are not connected on GX4000 so the associated inputs are not defined (possibly high):
   * Printer (data and strobe)
   * Keyboard lines 0,1,2,4,5,7,8
   * FDC
   * FDD motor
   * Cassette read, write, motor
  • When a system cartridge is inserted (this has been verified with a yellow and a green labelled system cartridge), the copyright message and a Ready prompt is displayed. If the fire buttons or directions are pressed on the first digital joystick you see X,Z and the arrows displayed, the same as if you had pressed these buttons on a 464/6128 Plus or CPC. Pressing Pause displays "P".

Specific Software for CPC+/GX4000

Graphic utilities

To complete... See Applications for exact words

Music software

To complete with software able to use dma sound playlist... See Applications for exact words


Operating Systems


Pure CPC Plus demos

Demos with Plus features

  • to complete

Slide Shows


Non-cartridge games

Cartridges released for the GX4000


Said to have actually existed and even reviewed in some specialised press :

Games patched for the Amstrad CPC Plus

The following Amstrad CPC games have been patched for the Amstrad CPC Plus to take advantage of its extended colour palette:


Lately (as of May 2007) several instances of bootleg cartridges have appeared. These are not original releases and, although they could run without any problems, caution should be exercised when buying. What is more, their collectible/historical value is doubtful. For more details, see here

System Cartridges

Systems Cartridges with Parados

Included in Delivery


  • The computer itself, incl. built-in Datacorder
  • System Cartridge with AMSDOS(the Plus series were actyakky the first Amstrad machines to have the OS on a removable medium, as opposed to on-chop built-in OSes; nevertheless, this was not that bad as cartidge loading is instantaneous), Locomotive BASIC 1.1 and the game Burnin' Rubber
  • 1 Paddle
  • CPC464plus/CPC6128plus manual
  • Game manual
  • Either an Amstrad MM12 Monochrome Monitor or an Amstrad CM14 Colour Monitor


  • The computer itself, incl. built-in 3" disk drive
  • System Cartridge with AMSDOS (the Plus series were actually the first Amstrad machines to have the OS on a removable medium, as opposed to on-chop built-in OSes; nevertheless, this was not that bad as cartidge loading is instantaneous, Locomotive BASIC 1.1 and the game Burnin' Rubber
  • System Disk with CP/M Plus and utilities, identical disk for all countries
  • 1 Paddle
  • 464plus/6128plus manual
  • Game manual
  • Either an Amstrad MM12 Monochrome Monitor or an Amstrad CM14 Colour Monitor


Showing the GX4000 in action


Review of the GX4000 by Retro Zone


Emulators for CPC Plus