Difference between revisions of "Amstrad GX4000"

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(Technical specifications)
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==Technical specifications==
 
==Technical specifications==
 +
  
 
*CPU: 8/16-bit [http://en.wikipedia.org/wiki/Zilog Zilog] Z80A at 4 MHz<sup class="reference" id="cite_ref-GX4000_at_Old_Computers_2-3" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-GX4000_at_Old_Computers-2 [2]]</sup>
 
*CPU: 8/16-bit [http://en.wikipedia.org/wiki/Zilog Zilog] Z80A at 4 MHz<sup class="reference" id="cite_ref-GX4000_at_Old_Computers_2-3" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-GX4000_at_Old_Computers-2 [2]]</sup>
 
*ASIC: Support for sprites, soft scrolling, programmable interrupts, DMA Sound<sup class="reference" id="cite_ref-Arnold_V_Specifications_13-0" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-Arnold_V_Specifications-13 [13]]</sup>
 
*ASIC: Support for sprites, soft scrolling, programmable interrupts, DMA Sound<sup class="reference" id="cite_ref-Arnold_V_Specifications_13-0" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-Arnold_V_Specifications-13 [13]]</sup>
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<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">
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</p>
 
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Resolution'''<sup class="reference" id="cite_ref-Arnold_V_Specifications_13-1" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-Arnold_V_Specifications-13 [13]]</sup></p>
 
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Resolution'''<sup class="reference" id="cite_ref-Arnold_V_Specifications_13-1" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-Arnold_V_Specifications-13 [13]]</sup></p>
 +
 +
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;"><span style="line-height:20px;">Based on the amstrad CPC hardware, you have the same standard 16KB video modes :</span></p>
  
  
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*Mode 1: 320x200 pixels with 4 colours
 
*Mode 1: 320x200 pixels with 4 colours
 
*Mode 2: 640x200 pixels with 2 colours
 
*Mode 2: 640x200 pixels with 2 colours
 +
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Overscan resolutions :'''</p>
 +
 +
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;"><span style="line-height:20px;">The screen size is re-dimensionable, the pixel sizes stay the same as it just reduce the border.</span></p>
 +
 +
 +
*Mode 0: 192x272 pixels with 16 colours
 +
*Mode 1: 384x272 pixels with 4 colours
 +
*Mode 2: 768x272 pixels with 2 colours
 +
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;"><span style="line-height:20px;">It is possible to have multiple mode on screen with raster interrupts.</span></p>
 +
 +
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">
 +
</p>
 
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Colour'''<sup class="reference" id="cite_ref-GX4000_at_Old_Computers_2-4" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-GX4000_at_Old_Computers-2 [2]]</sup></p>
 
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Colour'''<sup class="reference" id="cite_ref-GX4000_at_Old_Computers_2-4" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-GX4000_at_Old_Computers-2 [2]]</sup></p>
  
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<p style="margin-top:0.4em;margin-bottom:0.5em;line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Sprites''' <sup class="reference" id="cite_ref-Arnold_V_Specifications_13-2" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-Arnold_V_Specifications-13 [13]]</sup></p>
 
<p style="margin-top:0.4em;margin-bottom:0.5em;line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Sprites''' <sup class="reference" id="cite_ref-Arnold_V_Specifications_13-2" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-Arnold_V_Specifications-13 [13]]</sup></p>
 +
 +
<p style="margin-top:0.4em;margin-bottom:0.5em;line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;"><span style="line-height:20px;">The Hardware sprites have to be uploaded into the ASIC. They can hardly be fast changed or multiplexed, and are coded in 8bpp despite having only 16 inks.</span></p>
  
  
 
*Number: 16 high resolution sprites per line
 
*Number: 16 high resolution sprites per line
*Sizes: 16x16 (each sprite can be magnified 2x or 4x in X and Y)
+
*Sizes: 16x16 pixels, each sprite can be magnified 2x or 4x in X and Y, the basic 1x size is the same as for Mode2 pixels.
*Colours: Each sprite can use up to 15 colours
+
*Colours: Each sprite can use up to 15 colours from the same sprite palette (16 inks : 15 colours + transparency)
 +
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">
 +
</p>
 
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Memory''' <sup class="reference" id="cite_ref-Arnold_V_Specifications_13-3" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-Arnold_V_Specifications-13 [13]]</sup></p>
 
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Memory''' <sup class="reference" id="cite_ref-Arnold_V_Specifications_13-3" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-Arnold_V_Specifications-13 [13]]</sup></p>
 +
 +
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;"><span style="line-height:20px;">Being based on a computer system, this console has a huge RAM capacity compaired to other 8 bit consoles. But no specific VRAM. The fact that released cartridges were limited to 128kB was quite a setback, but 512kB cartridges are possible.</span></p>
  
  
 
*RAM: 64 kB
 
*RAM: 64 kB
*VRam: 16 kB
+
*VRam: 16 kB : There is no real dedicated VRAM, RAM banks can be used as VRAM, the Z80 is then put on wait state while the video circuit reads the RAM bank. Also it is possible to get an overscan mode : the video circuit would read more than one RAM bank, the displayable zone is something like 24K.
*[http://en.wikipedia.org/wiki/Read-only_memory ROM]: 32 kB
+
*[http://en.wikipedia.org/wiki/Read-only_memory ROM]: depends on the LKs settings on the cartridge and the ROM/EPROM used. From 16kB to 512kB. All cartridges released used 128kB though.
 +
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">
 +
</p>
 
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Audio'''</p>
 
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''Audio'''</p>
 +
 +
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;"><span style="line-height:20px;">GX4000/Amstrad PLUS use the same AY as used on ORIC ATMOS, ZXspectrum128/+2/+3, MSX1, AmstradCPC or AtariST (YM clone), yet it may be clocked differently.</span></p>
  
  
 
*3-channel stereo; [http://en.wikipedia.org/wiki/General_Instrument_AY-3-8910 AY-3-8912 chip]<sup class="reference" id="cite_ref-GX4000_at_Old_Computers_2-5" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-GX4000_at_Old_Computers-2 [2]]</sup>
 
*3-channel stereo; [http://en.wikipedia.org/wiki/General_Instrument_AY-3-8910 AY-3-8912 chip]<sup class="reference" id="cite_ref-GX4000_at_Old_Computers_2-5" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-GX4000_at_Old_Computers-2 [2]]</sup>
*DMA
+
*3-DMA channels : the ASIC has DMA channels for the AY, enabling to lessen the CPU when playing samples or stuffs.
 +
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">
 +
</p>
 
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''IO'''<sup class="reference" id="cite_ref-GX4000_at_Old_Computers_2-6" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-GX4000_at_Old_Computers-2 [2]]</sup></p>
 
<p style="line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">'''IO'''<sup class="reference" id="cite_ref-GX4000_at_Old_Computers_2-6" style="line-height:1em;unicode-bidi:-webkit-isolate;">[http://en.wikipedia.org/wiki/Amstrad_GX4000#cite_note-GX4000_at_Old_Computers-2 [2]]</sup></p>
  
<p style="margin-top:0.4em;margin-bottom:0.5em;line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">Audio output, 2x Digital controller connectors, Analog controller port (IBM standard), Lightgun connector (RJ11), Audio and RGB Video output (8-pin DIN), Power supply socket from external PSU, Power supply socket from monitor.</p>
+
<p style="margin-top:0.4em;margin-bottom:0.5em;line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">Audio output, 2x Digital controller connectors, Analog controller port (IBM standard, well, not exactly), Lightgun connector (RJ11), Audio and RGB Video output (8-pin DIN), Power supply socket from external PSU, Power supply socket from monitor.</p>
  
 
<p style="margin-top:0.4em;margin-bottom:0.5em;line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">
 
<p style="margin-top:0.4em;margin-bottom:0.5em;line-height:19.1875px;color:rgb(0,0,0);font-family:sans-serif;text-align:start;">

Revision as of 14:07, 27 October 2013

The GX4000 was Amstrad's short-lived attempt to enter the games console market. The console was released in Europe in 1990 and was an upgraded design based on the then still-popular CPC technology. The GX4000 shared hardware architecture with Amstrad's CPC Plus computer line, which were released concurrently, this allowed the system to be compatible with the majority of CPC Plus software.

The GX4000 was both Amstrad's first and only attempt at entering the console market. Although offering enhanced graphics capabilities, it failed to gain popularity in the market, and was quickly discontinued, selling 15,000 units in total.

A computer turned into a console

The GX4000 is a game console based on a 6128 Plus 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 Plus). It was delivered with two game paddles (as the ones delivered with the Plus models) and Burnin' Rubber on  cartridge (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.

Technical specifications

  • CPU: 8/16-bit Zilog Z80A at 4 MHz[2]
  • ASIC: Support for sprites, soft scrolling, programmable interrupts, DMA Sound[13]

Resolution[13]

Based on the amstrad CPC hardware, you have the same standard 16KB video modes :


  • Mode 0: 160x200 pixels with 16 colours
  • Mode 1: 320x200 pixels with 4 colours
  • Mode 2: 640x200 pixels with 2 colours

Overscan resolutions :

The screen size is re-dimensionable, the pixel sizes stay the same as it just reduce the border.


  • Mode 0: 192x272 pixels with 16 colours
  • Mode 1: 384x272 pixels with 4 colours
  • Mode 2: 768x272 pixels with 2 colours

It is possible to have multiple mode on screen with raster interrupts.

Colour[2]


  • Depth: 12-bit RGB
  • Colours available: 4096
  • Maximum colours onscreen: 32 (16 for background, 15 for sprites, 1 for border)

Maximum onscreen colour counts can be increased in all Modes through the use of interrupts.

Sprites [13]

The Hardware sprites have to be uploaded into the ASIC. They can hardly be fast changed or multiplexed, and are coded in 8bpp despite having only 16 inks.


  • Number: 16 high resolution sprites per line
  • Sizes: 16x16 pixels, each sprite can be magnified 2x or 4x in X and Y, the basic 1x size is the same as for Mode2 pixels.
  • Colours: Each sprite can use up to 15 colours from the same sprite palette (16 inks : 15 colours + transparency)

Memory [13]

Being based on a computer system, this console has a huge RAM capacity compaired to other 8 bit consoles. But no specific VRAM. The fact that released cartridges were limited to 128kB was quite a setback, but 512kB cartridges are possible.


  • RAM: 64 kB
  • VRam: 16 kB : There is no real dedicated VRAM, RAM banks can be used as VRAM, the Z80 is then put on wait state while the video circuit reads the RAM bank. Also it is possible to get an overscan mode : the video circuit would read more than one RAM bank, the displayable zone is something like 24K.
  • ROM: depends on the LKs settings on the cartridge and the ROM/EPROM used. From 16kB to 512kB. All cartridges released used 128kB though.

Audio

GX4000/Amstrad PLUS use the same AY as used on ORIC ATMOS, ZXspectrum128/+2/+3, MSX1, AmstradCPC or AtariST (YM clone), yet it may be clocked differently.


  • 3-channel stereo; AY-3-8912 chip[2]
  • 3-DMA channels : the ASIC has DMA channels for the AY, enabling to lessen the CPU when playing samples or stuffs.

IO[2]

Audio output, 2x Digital controller connectors, Analog controller port (IBM standard, well, not exactly), Lightgun connector (RJ11), Audio and RGB Video output (8-pin DIN), Power supply socket from external PSU, Power supply socket from monitor.

Cartridge Games