Amstrad CPC: the all-in-one computer

01What you'll learn

• What "all-in-one" meant and why it was the bold idea behind the CPC.
• What the hardware is: processor, memory, graphics modes, palette, sound, disks.
• How the 464, 664, 6128, 472 and the Plus range differ and what they cost at launch.
• Why Spain got a CPC with "72 KB" of memory that does not work.
• What Locomotive BASIC looks like: a line, colours, sound and disk handling.
• How to run a CPC today in an emulator and where to find games and documentation.

02Before you start

• No prior knowledge is needed. The reading stands on its own; the hands-on part is optional.
• For the hands-on part: an emulator 🔒 local on your own computer. Three options are listed in step 8.
• Amstrad has allowed the CPC ROMs (the built-in software) to be distributed freely as long as the copyright message is not changed (Wikipedia). The games, however, have owners — download them only from places that offer them legally.
• Plan about 15 minutes for the history and another 15 for the emulator experiment.

03Steps

1. The idea: a computer that is a whole system

   In the mid-1980s most home computers (ZX Spectrum, Commodore 64, BBC Micro) plugged into the family TV and used an external tape recorder or disk drive. The CPC was conceived differently: keyboard, computer and storage device in one box, always sold together with a monitor — green, monochrome or colour. The monitor was also the computer's power supply. Why does it matter? The buyer did not have to assemble anything or fight over the family television, and the price of the whole system was low for its time. Founder Alan Sugar wanted the machine to look like a "real computer", not a toy. The all-in-one idea was not new — it existed in business machines and in the Commodore PET — but on the home market it was unusual.

   The CPC entered a market dominated by the C64 and the Spectrum. It established itself mainly in the United Kingdom, France, Spain, Germany (under the Schneider brand) and other German-speaking countries, and in Canada. Over 1984–1990 about 3 million CPCs were sold, of which more than 2 million were the 464.

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   What we could not confirm

   The old lesson called the CPC "the third big one" and credited it with winning whole countries. We could not verify market share, so we only say: it established itself in the countries listed.

2. The hardware in numbers

   Part	What the original CPCs have
   Processor	Zilog Z80A, 4 MHz. Because memory is shared with the video, the effective speed is about 3.3 MHz.
   Memory	64 KB (464, 664) or 128 KB (6128); external expansions up to 512 KB.
   Video	Mode 0: 160×200 and 16 colours · Mode 1: 320×200 and 4 colours · Mode 2: 640×200 and 2 colours.
   Palette	27 colours (Plus: 4096). Chips: Motorola 6845 + a custom gate array.
   Sound	AY-3-8912: three channels, each can produce a square wave, noise or both.
   Storage	Built-in tape deck (464) or 3-inch disk drive (664, 6128).
   Language	Locomotive BASIC 1.0 (464) and 1.1 (all the others).

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   The 3-inch disks

   The drive is made by Matsushita and is compatible with the Hitachi format. It is single-sided — to use the second side you flip the disk. Each side holds about 180 KB (178 KB for files), 360 KB in total. The disks are sturdier than 3.5-inch ones but considerably more expensive, and the format disappeared soon after the CPC itself.

3. Locomotive BASIC: try it yourself

   Amstrad commissioned its BASIC from Locomotive Software. The special thing is that graphics and sound are controlled with ready-made commands, without the low-level POKE that most BASICs of the time needed. There are also AFTER and EVERY timers. Version 1.0 shipped only on the 464 (with one known bug in the DEC$ function); version 1.1 is on the others and adds, for example, FILL. The example draws a frame in four colours; coordinates are 640×400 with the origin at bottom left, regardless of the mode.

   Locomotive BASIC · frame and soundcopy

   10 MODE 1: BORDER 0
   20 INK 0,0: INK 1,24: INK 2,6: INK 3,18
   30 PLOT 100,100,1
   40 DRAW 500,100,2
   50 DRAW 500,300,3
   60 DRAW 100,300,1
   70 DRAW 100,100,2
   80 SOUND 1,200,100,12
   RUN

   The numbers in INK come from the factory table of the 27 colours: 0 is black, 24 is bright yellow, 6 is bright red, 18 is bright green, 26 is bright white. INK 0,0 makes the background black, and INK 1,24 gives pen 1 the colour bright yellow.

   Locomotive BASIC · sound channels and disk handlingcopy

   ' SOUND channel, tone period, duration, volume, volume envelope, tone envelope, noise
   SOUND 1,200,100,12          ' channel A; larger period = lower pitch
   SOUND 2,300,100,10          ' channel B
   SOUND 4,0,50,13,0,0,15      ' channel C (4), no tone, noise is the 7th parameter
   
   CAT                          ' contents of the disk or tape
   SAVE "MYPROG"                ' save the program
   LOAD "MYPROG"                ' load it
   RUN "MYPROG"                 ' load and start

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   Traps

   The channel values in SOUND are 1, 2 and 4 (A, B, C) — not 1, 2, 3 — and 4 is not noise. There is no CIRCLE command — you draw a circle with your own program made of lines. Volume without an envelope is 0 to 7 on the CPC 464 (BASIC 1.0) and 0 to 15 on the 664 and 6128 (BASIC 1.1) — on a 464 use values up to 7. Both listings run without error in the CPCBasicTS 0.5.7 interpreter (01.10.2026), but have not been run in a full CPC emulator, so test them yourself before reusing them.

4. The models and prices

   The prices are the recommended ones at launch in the United Kingdom, in British pounds: the first is with a green screen, the second with a colour monitor (where announced).

   Model	Year	Memory	Storage	Price £ (green / colour)
   CPC 464	June 1984	64 KB	tape deck	249 / 359
   CPC 664	25.04.1985	64 KB	3" disk	339 / 449
   CPC 6128	summer 1985	128 KB	3" disk	299 / 399
   CPC 472	1985	"72 KB"	tape deck	Spain only
   464 plus	1990	64 KB	tape deck + cartridge in the box	229 (mono) / 329 (colour)
   6128 plus	1990	128 KB	3" disk	329 (mono) / 429 (colour)
   GX4000	1990	64 KB	cartridge	99.99 (United Kingdom)

   The 6128 also had a business advantage: it runs CP/M Plus. After its launch the 464 price dropped by £50. The 664 lived only about six months and was discontinued when the 6128 arrived.

5. Spain and France

   Spain and the CPC 472. In August 1985 Spain briefly introduced an import tax of 15,000 pesetas (€90.15) on computers with 64 KB of memory or less, and a separate royal decree required computers sold in Spain to have a Spanish keyboard. Amstrad's distributor Indescomp created the CPC 472: a CPC 464 with a small extra board — with a ROM from the 664 and an 8 KB chip. That chip is not electrically connected; its only purpose was to raise the stated memory to 72 KB and avoid the tax. The keyboard gained an ñ key. After Spain joined the European Communities the tax was dropped, production of the 472 stopped, and the ñ key was added to the 464.

   In Spain the ZX Spectrum and the Amstrad CPC were the best-selling 8-bit computers. A local games industry grew up around them — Opera Soft, Dinamic, Topo Soft, Zigurat and others; the period is known as the "golden age of Spanish software".

   France. The state plan "Informatique pour tous" (1985) equipped schools mainly with Thomson machines (MO5, TO7/70) and servers from Bull and other French companies — the CPC was not part of that scheme. In France the CPC found its audience elsewhere: in homes. One of the best-known French CPC hits is Crafton & Xunk, known in the United Kingdom as Get Dexter.

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   Germany

   In Germany, Austria and Switzerland Amstrad had no sales network of its own and from 1984 sold through Schneider: there the CPC was called Schneider CPC, with small differences (for example grey keys on the 464 and 664).

6. Three games worth knowing

   Game	Year · publisher	Why we remember it
   La Abadía del Crimen	1987 · Opera Soft (Spain)	An isometric adventure based on Umberto Eco's "The Name of the Rose"; programmer Paco Menéndez, artist Juan Delcán. It was developed first for the CPC 6128, and the 464 version was cut down to fit 64 KB. It was never officially released outside Spain, but has a cult status there.
   Get Dexter (Crafton & Xunk)	1986 · ERE Informatique (France), PSS (United Kingdom)	An isometric science-fiction puzzle game; programmer Remi Herbulot. Amstrad Action gave it a "Mastergame" award.
   Harrier Attack	1983 · Durell Software; CPC version — 1984	A side-scrolling shooter with a Harrier jet set in the Falklands War. It came out first for the Spectrum and Oric, so it is not "the first game for the CPC" as the old lesson claimed.

7. Timeline 1984–1990

   When	What happens
   June 1984	The CPC 464 is released in the United Kingdom.
   25.04.1985	CPC 664 with a disk drive.
   summer 1985	CPC 6128: first only in the USA (13.06.), in Europe from 15.08.
   August 1985	The Spanish tax and the CPC 472.
   7.04.1986	Amstrad buys the rights to the Sinclair computers and brand for £5 million; it then launches the ZX Spectrum +2 and +3.
   1987	La Abadía del Crimen is released.
   autumn 1990	The Plus range (4096 colours, 16 hardware sprites, smooth scrolling, DMA sound) and the GX4000 console. The market is already looking to the Amiga and Mega Drive; the Plus range fails.
   1991	The GX4000 is discontinued after only 27 games; sales are weak (by some estimates under 15,000 units; the figure is disputed).

8. The CPC today: emulators and documentation

   The easiest way to get your hands on a CPC is an emulator 🔒 local. As of 01.10.2026 we checked:

   Emulator	Platform	Version (checked)
   Retro Virtual Machine 2	Windows, macOS, Linux, Raspberry Pi	v2.1.20, 14.06.2025 (the latest on its site)
   Caprice32	Windows, Linux, macOS	latest release v4.6.0 (2020); GitHub has a newer continuous build from 14.02.2025
   WinAPE	Windows	2.0 Beta 2, 6.01.2016; built-in assembler and debugger; free

   Documentation and software: CPCWiki is the most detailed reference (🌐 global; the site refuses requests from automated programs — open it in a browser ⚠️), and CPC-Power is a database of thousands of programs, manuals and articles, in French and English.

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   Try it now

   Start an emulator, type the first listing from step 3 line by line (with RETURN after each) and type RUN. If you get "Syntax error", check that you put the colons and commas exactly as in the text.

04Check

Checklist

• You can name the processor, the memory sizes, the screen modes and the number of colours.
• You can explain what "all-in-one" meant and why the monitor was part of the bundle.
• You tell the 464, 664, 6128, 472 and Plus apart and know their approximate prices.
• You know why the CPC 472 has "72 KB" and that the extra 8 KB does not work.
• You know that Locomotive BASIC has no CIRCLE and that SOUND 4 is channel C.
• You have an emulator or know where to get one.

Quiz

05What's next

06Sources

1. Amstrad CPC — Wikipedia: models, dates, prices, hardware, CPC 472, Sinclair.
2. GX4000 — Wikipedia: the console, its price, its games.
3. Locomotive BASIC — Wikipedia: versions 1.0 and 1.1, commands.
4. CPC464/664/6128 Firmware, Appendix V: Inks and Colours — the official colour table (PDF).
5. Amstrad CPC BASIC: sound effects and music — an introductory tutorial on SOUND.
6. La Abadía del Crimen, Get Dexter, Harrier Attack — Wikipedia.
7. The Informatique pour tous plan — Wikipedia: which machines were chosen.
8. Golden age of Spanish software — Wikipedia: the Spanish studios and the Spectrum/CPC market.
9. Retro Virtual Machine · Caprice32 · WinAPE — emulators 🔒 local.
10. CPC-Power 🌐 global — a database of programs and articles; CPCWiki (cpcwiki.eu) — open in a browser.