Amstrad CPC 2197 226072548 2008-07-16T18:30:23Z MattieTK 434929 Reverted edits by [[Special:Contributions/80.7.178.59|80.7.178.59]] to last version by PeterCanthropus (using [[WP:HG|Huggle]]) {{Refimprove|date=September 2007}} {{weasel}} {{Infobox computer |Photo = [[Image:Amstrad CPC464.jpg|290px|Amstrad CPC 464, with CTM644 colour monitor]] |Type = [[Personal computer]] |Released = 1984 |Discontinued = 1990 |Processor = Zilog Z80A @ 4&nbsp;MHz |Memory = 64 to 576 [[Kilobyte|KB]] ([[KiB]]) |OS = Locomotive BASIC 1.0, 1.1 and [[CP/M]] }} The '''Amstrad CPC''' was a series of [[8-bit]] [[home computer]]s produced by [[Amstrad|Amstrad Plc]] during the 1980s and early 1990s. CPC stood for 'Colour Personal Computer', although it was possible to purchase a CPC with a [[green screen]] (GT65/66) as well as with the standard colour screen (CTM640). The first machine, the CPC 464, introduced in 1984, was designed as a direct competitor to the [[Commodore 64]] and [[Sinclair Research Ltd|Sinclair]] [[ZX Spectrum]] systems. Packaged as a "complete system" the CPC 464 came with its own monitor and built-in [[Compact audio cassette|cassette tape]] deck. The CPC 664, with its own built-in [[Floppy drive#The 3-inch compact floppy disk|floppy disk drive]], arrived early in 1985, to be replaced itself later that same year by the CPC 6128. In 1990, Amstrad launched the CPC 464 and 6128 Plus range featuring tweaked hardware from the old CPC range. The original CPC range was successful, especially in [[Europe]], with over three million units sold. Following this success, Amstrad launched the [[Amstrad PCW]] word-processor range, which was a bigger success, with eight million units sold. Variations and clones of the CPC range were also released in [[Germany]]. However, the Plus range failed to find a market amongst the higher spec 16-bit computers of the competing [[Atari ST]] and [[Commodore Amiga]] systems. ==Models== [[Image:Amstrad CPC Advert.png|right|thumb|250px|UK advert for the Amstrad&nbsp;CPC&nbsp;464]] The CPC 464 was introduced in 1984 and was designed to be a direct competitor to the [[Commodore 64]] and [[Sinclair Research Ltd|Sinclair]] [[ZX Spectrum]] systems.<ref name="Amstrad products">{{cite web | last = | first = | authorlink = | coauthors = | title =Amstrad products | work = | publisher =Amstrad Plc | date = | url =http://www.amstrad.com/products/archive/index.html | format = | doi = | accessdate =2008-05-06 }}</ref> <ref name="464 Old Computers">{{cite web | last = | first = | authorlink = | coauthors = | title =464 Old Computers | work = | publisher =Old-Computers.com | date = | url =http://www.old-computers.com/museum/computer.asp?c=84 | format = | doi = | accessdate =2008-05-06 }}</ref> Amstrad promoted the CPC as being a "complete system" - including everything required to use the machine in one box.<ref name="464 Old Computers"/> Compared to a C64 or a ZX Spectrum, the Amstrad CPCs shipped with their own monitor, had a built in tape recorder or floppy disk drive and a small loudspeaker.<ref name="464 Old Computers"/> This marketing gave a "professional" appeal to the Amstrad CPC by marketing it in the same way as business-oriented systems, rather than gaming or home oriented ones. In early 1985 Amstrad launched the CPC 664 model.<ref name="664 Old Computers">{{cite web | last = | first = | authorlink = | coauthors = | title =664 Old Computers | work = | publisher =Old-Computers.com | date = | url =http://www.old-computers.com/museum/computer.asp?c=112 | format = | doi = | accessdate =2008-05-06 }}</ref> This was similar to the 464, but with the addition of a built-in [[Floppy drive#The 3-inch compact floppy disk|floppy disk drive]] instead of a tape deck.<ref name="664 Old Computers"/> However, production on the CPC 664 quickly stopped when its replacement the CPC 6128 was launched later in 1985.<ref name="664 Old Computers"/> <ref name"Amstrad products">{{cite web | last = | first = | authorlink = | coauthors = | title =Amstrad products | work = | publisher =Amstrad Plc | date = | url =http://www.amstrad.com/products/archive/index.html | format = | doi = | accessdate =2008-05-06 }}</ref> This new model not only contained the built-in floppy disk drive but had 128KB of memory.<ref name="6128 Old Computers">{{cite web | last = | first = | authorlink = | coauthors = | title =6128 Old Computers | work = | publisher =Old-Computers.com | date = | url =http://www.old-computers.com/museum/computer.asp?c=111 | format = | doi = | accessdate =2008-05-06 }}</ref> Outwardly, the most distinguishing features of Amstrad's offering were the matte black console case with sharp corners and narrowly rectangular form factor (the latter due to the built-in [[Compact audio cassette|cassette tape]] deck (CPC 464) or floppy disk drive (CPC 664 and CPC 6128), the keyboard's distinctly coloured special keys (all the non-typewriter-standard keys on the 464 and 664), and the unique power supply hookup with one lead going from the monitor to the computer (or RF modulator) and, on disc-based machines, one lead going the other way. A television could be used with an optional adapter, and an optional tuner was available to turn the monitor into a TV. An external disk drive (DDI-1) was available for the 464, incorporating the DOS in an interface unit. A second drive (FD-1) could be added to both this and 664/6128 machines. Cassette recorders could also be connected to the 664 and 6128. By and large, the later versions were compatible with earlier machines, though there were incompatibilities in undocumented features. Third-party hardware add-ons such as Romantic Robot's popular [[Multiface]] allowed DIY backup of most tape software to disk. As a late entrant to the European 8-bit market, the CPC range never achieved the total sales volume of either the ZX Spectrum or the C64, but the advantages of a typewriter-style keyboard and integrated tape or floppy drive saw it obtain considerable market share in the late 80s. It became the best-selling computer in [[France]] at this time and was popular in [[Spain]]. Many of the best software titles for the CPC were created on the continent, but only a limited number saw commercial release in the UK.{{Fact|date=April 2008}} ===Variations=== [[Image:Schneider_CPC6128.jpg|thumb|Schneider CPC6128 from West Germany]] Amstrad's German partner company Schneider produced its own models of the CPC 464, 664 and 6128. These machines had grey keys in place of the Amstrad coloured alternatives, and industry-standard D-connector [[Micro ribbon|Centronics]] ports in place of the edge connectors. They were otherwise identical at the hardware level, with a link on the PCB being set to configure the sign-on message as Schneider rather than Amstrad. Documentation and case labels were translated into German. Like most other computers of the era, the CPC inspired a clone in the [[Eastern bloc]] - the KC compact, made in [[East Germany]] using [[Soviet Union|Soviet]] and East German components. The machine differed from a CPC visually with a different style of case, external power supply and (optional and even more scarce than the main device) external 5.25" [[Robotron]] disc drive. Unlike the Amstrad models it could be used with a television screen out of the box. It ran BASIC 1.1 and a CP/M clone, the German-language MicroDOS. It had 64 KB RAM built in and an additional 64 KB RAM was provided with the external disc/tape drive adapter. The Z80 processor was replaced with a U 880 (which is 100% [[Bug compatibility|bug-compatible]]), and some proprietary Amstrad I/O chips replaced with clones based on the Z8536. This clone machine was around 95% compatible with the original. ==Plus models== [[Image:6128plus es.jpg|thumb|right|The 6128 Plus keyboard]] In 1990 Amstrad introduced the "Plus" series, 464 and 6128 Plus, which tweaked the hardware and added a [[Cartridge (electronics)|cartridge]] slot to the system.<ref name="Plus range at Old Computers">{{cite web | last = | first = | authorlink = | coauthors = | title =Plus range at Old Computers | work = | publisher =Old-Computers.com | date = | url =http://www.old-computers.com/museum/computer.asp?st=1&c=26 | format = | doi = | accessdate =2008-05-06 }}</ref> Improvements were made to the video display which saw an increase in palette to 4096 colours and gained a capacity for [[Sprite (computer graphics)|hardware sprites]].<ref name="Plus range at Old Computers"/> Splitting the display into separate modes and [[pixel]] scrolling both became fully supported hardware features, although the former was easy, and the latter possible to some degree, 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, enabling high-quality samples to be replayed with minimal processor overhead; the sound chip itself, however, remained unchanged.<ref name="Plus range at Old Computers"/> Additionally, the BASIC command set for disc access was improved. A cut down CPC Plus, without the keyboard, nor support for non-cartridge media, was also released as the [[Amstrad GX4000|GX4000]] [[video game console]].<ref name="Plus range at Old Computers"/> These models did not do well in the marketplace, failing to attract any substantial third party support.<ref name="GX4000 at Old Computers">{{cite web | last = | first = | authorlink = | coauthors = | title =GX4000 Old Computers | work = | publisher =Old-Computers.com | date = | url =http://www.old-computers.com/museum/computer.asp?st=2&c=1082 | format = | doi = | accessdate =2008-05-06 }}</ref> The 8-bit technology behind the CPC was starting to look out-of-date by 1990 and Amstrad's marketing failed to promote any significant advantage over the competing [[Atari ST]] and [[Commodore Amiga]] systems.<ref name="GX4000 at Old Computers"/> The new models were not helped by the substantial price hike for cartridge games compared to their tape and disc counterparts, exacerbated by the tendency to rerelease old CPC games on cartridge without taking advantage of the enhanced Plus hardware. ==Technical specifications== *'''CPC 464''' &ndash; Tape deck, 64 [[kilobyte|KB]] [[random access memory|RAM]].<ref name="464 Old Computers"/> *'''CPC 472''' &ndash; Tape deck, 72 KB RAM; produced in small numbers for the Spanish market to avoid a legal ruling requiring that computers with 64 KB or less RAM must be localized to the Spanish language, including the keyboard and screen messages. The law was subsequently changed to include machines with more than 64 KB RAM so a localised version of the 472 also exists.<ref>[http://perso.wanadoo.es/amstradcpc/cpc/cpc472.html amstradmuseum.com cpc 472<!-- Bot generated title -->]</ref> *'''CPC 664''' &ndash; 3" Floppy disk drive, 64 KB RAM. *'''CPC 6128''' &ndash; 3" Floppy disk drive, 128 KB RAM. CPC models were based on a [[Zilog Z80]] processor clocked at {{nowrap|4&nbsp;MHz}}.<ref name="464 Tech spec">Technical Specification, CPC464 Service Manual, p. 2., Amstrad Consumer Electronics Plc.</ref> Because a common pool of RAM is shared with the video circuits, the Z80 may only make a memory accesses every four cycles - which has the effect of rounding instruction cycle lengths up to the next multiple of four. The speed is therefore roughly equivalent to a {{nowrap|3.3&nbsp;MHz}} machine. The system came with 64 [[Kilobyte|KB]] or 128 KB of RAM depending on the model (capable of being expanded to 512k within the Amstrad-standard address space).<ref name="464 Tech spec"/> <ref name="6128 Tech spec">Technical Specification, CPC6128 Service Manual, p. 31., Amstrad Consumer Electronics Plc.</ref> The machines also featured an (almost) standard 9-pin [[Atari]]-style [[joystick]] socket which was able to take two joysticks via a splitter.<ref name="464 Tech spec"/> The hardware and firmware was designed so that it could access external ROMs with software in them. Each ROM had to be a 16k block and was switched in and out of the memory space shared with the video RAM. The Amstrad firmware was deliberately designed so that new software could be easily accessed from these ROMs with minimum of fuss. Popular applications were marketed on ROM, particularly word processing and programming utility software (examples are PROTEXT and BRUNWORD of the former, and MAXAM Assembler of the latter type) Such extra ROM chips did not plug directly into the CPC itself, but into extra plug-in "rom-boxes" which contained sockets for the ROM chips and a minimal amount of decoding circuitry for the main machine to be able to switch between them. These boxes were either marketed commercially or could be built by competent hobbyists and they attached to the main expansion port at the back of the machine. Software loaded from ROM this way was accessible much more quickly than if it had to be loaded from a disc or tape and the machine's boot-up sequence was cleverly designed to evaluate ROMs it found and if they wished, hand over control of the machine to them. This allowed complete customisation of the function of the machine, something that research labs and garage techies were happy to exploit for all manner of purposes. However, the typical user was normally unaware of this added ROM functionality as it was not described in the user manual and was hardly ever mentioned in marketing literature. It was, however, documented in the Firmware manual published by Amstrad. === Video === Underlying the CPC's video output was the Motorola 6845 [[Video Display Controller|address generator]]. This chip was connected to a pixel generator that supported 4 bpp, 2 bpp and 1 bpp output (bpp = [[color depth|bits per pixel]]). The address generator was clocked at a constant rate so the 4 bpp display generated half as many pixels as the 2 bpp and a quarter as many as the 1 bpp. Three built-in display resolutions were available, though increased screen size could be achieved by reprogramming the 6845. The standard video modes were: * '''Mode 0''': '''160×200''' pixels with 16 colors (4 [[color depth|bpp]])<ref name="464 Tech spec"/> * '''Mode 1''': '''320×200''' pixels with 4 colors (2 bpp)<ref name="464 Tech spec"/> * '''Mode 2''': '''640×200''' pixels with 2 colors (1 bpp)<ref name="464 Tech spec"/> A colour [[Palette (computing)|palette]] of 27 colors was supported,<ref name="464 Tech spec"/> derived from [[RGB]] colour space with each component assigned as either off, half on or on. The later Plus models extended this to 4096 colours and added support for hardware sprites.<ref name="Plus range at Old Computers"/> The machine lacked an [[RF modulator|RF TV]] or [[composite video]] output and instead shipped with a proprietary 6-pin [[DIN connector]] intended for use solely with the supplied Amstrad monitor.<ref name="464 Tech spec"/> An external adapter for RF TV was available to buy separately. The 6-pin DIN connector is capable of driving a [[SCART]] television with a correctly wired lead. The video signals are [[PAL]] frequency 1v p-p analogue RGB with composite sync. ===Audio === The CPC used the [[General Instrument AY-3-8910|General Instrument AY-3-8912]] [[sound chip]],<ref name="464 Tech spec"/> providing three channels, each configurable to generate square waves, white noise or both. A small array of hardware volume envelopes are available. Output was provided in mono by a small (4 [[Metre#SI multiples|cm]]) built-in loudspeaker with volume control, driven by an internal [[amplifier]]. [[Stereophonic sound|Stereo]] output was provided through a {{nowrap|3.5 mm}} [[headphones]] jack. Playback of [[sampling (signal processing)|digital sound samples]] at a resolution of approximately 5-bit, as heard on the title screen of the game ''[[RoboCop (video game)|RoboCop]]'', was possible by sending a stream of values to the sound chip. This trick was very processor-intensive and hard to combine with any other processing. ===Floppy disk drive=== [[Image:Amstrad-floppy.jpg|right|thumbnail|A 3" floppy disc used on CPC machines]] Amstrad's choice of [[Hitachi, Ltd.|Hitachi's]] 3" floppy disk drive, when the rest of the PC industry was moving to [[Sony]]'s 3.5" format, is often claimed to be due to Amstrad bulk-buying a large consignment of 3" drive units in [[Asia]]. The chosen drive (built-in for later models) was a single-sided 40-track unit that required the user to physically remove and flip the disk to access the other side.<ref name="6128 Tech spec"/> Each side had its own independent write-protect switch.<ref name="6128 Tech spec"/> The sides were termed "A" and "B", with each one commonly formatted to 180 kB (in [[AMSDOS]] format, comprising 2 kB directory and 178 kB storage) for a total of 360 kB per disc. The interface with the drives was a NEC 765 [[Floppy disk controller|FDC]], used for the same purpose in the IBM [[PC/XT]], [[PC/AT]] and [[IBM Personal System/2|PS/2]] machines. Its features were not fully used, in order to cut costs, namely [[Direct memory access|DMA]] transfers and support for [[single density]] disks; they were formatted as [[double density]] using [[Modified frequency modulation]]. Disks were shipped in a paper sleeve or a hard plastic case resembling a [[compact disc]] "jewel" case. The casing is thicker and more rigid than that of 3.5" diskettes. A sliding metal cover to protect the media surface is internal to the casing and latched, unlike the simple external sliding cover of Sony's version. Because of this they were significantly more expensive than both 5.25" and 3.5" alternatives. This, combined with their low nominal capacities and their essentially proprietary nature, led to the format being discontinued shortly after the CPC itself was discontinued. Apart from Amstrad's other 3" machines (the [[Amstrad PCW|PCW]] and the [[ZX Spectrum|ZX Spectrum +3]]), the few other computer systems to use them included the Sega SF-7000 and CP/M systems such as the [[Tatung Einstein]] and [[Osborne Computer Corporation|Osborne]] machines. They also found use on embedded systems. The [[Shugart]]-standard interface meant that Amstrad CPC machines were able to use standard 3", 3½" or 5¼" drives as their second drive. Programs such as ROMDOS and ParaDOS extended the standard [[AMSDOS]] system to provide support for double-sided, 80-track formats, enabling up to 800k to be stored on a single disk. ===Serial port adaptor=== Amstrad issued two [[RS-232|RS-232-C]] [[D-subminiature|D25]] serial interfaces, attached to the expansion connector at the rear of the machine, with a through-connector for the CPC464 disk drive or other peripherals. The original interface came with a "''Book of Spells''" for facilitating data transfer between other systems using a proprietary [[protocol (computing)|protocol]] in the device's own ROM, as well as [[computer terminal|terminal]] software to connect to British Telecom's [[Prestel]] service. A separate version of the ROM was created for the U.S. market due to the use of the commands "SUCK" and "BLOW", which were considered unacceptable there. Software and hardware limitations in this interface led to its replacement with an Amstrad-branded version of a compatible alternative by Pace. Other serial interfaces were available from third-party vendors such as KDS Electronics and Cirkit. ==Software== ===BASIC and operating system=== [[image:Amstrad CPC screen closeup.jpg|thumb|right|Locomotive BASIC on the Amstrad CPC 464]] Like most home computers at the time, the CPC had its [[operating system|OS]] and a [[BASIC programming language|BASIC]] [[interpreter (computer software)|interpreter]] built in as [[read-only memory|ROM]]. It used [[Locomotive BASIC]] - an improved version of Locomotive Software's Z80 BASIC for the [[BBC Microcomputer]] co-processor board. This was faster, more comfortable and more powerful than the generic but common [[Microsoft BASIC]] used by the Commodore 64 and [[MSX]] amongst others. It was particularly notable for providing easy access to the machine's video and audio resources in contrast to the arcane [[PEEK and POKE|POKE]] commands required on generic Microsoft implementations. ===Other languages=== Although it was possible to obtain compilers for Locomotive BASIC, [[C (programming language)|C]] and [[Pascal (programming language)|Pascal]], the majority of the CPC's software was written in native Z80a assembly language. Popular assemblers were Hisoft's Devpac, Arnor's Maxam, and (in France) DAMS. Disk-based CPC (not Plus) systems shipped with an interpreter for the educational language [[Logo programming language|LOGO]], booted from CP/M 2.2 but largely CPC-specific with much code resident in the AMSDOS ROM. === ''Roland'' === At launch, Amsoft had lined up a range of 50 games. A number of these (as well as several subsequent releases) were tagged with the Roland name, in an attempt to give the CPC a recognisable mascot. However, since the games had not been designed around the Roland character and only had the branding added later there was initially no consensus on what kind of games Roland should star in or even what he looked like. Roland's appearance varied immensely, from a spiky-haired blonde teenager (''Roland Goes Digging'') to a mutant flea (''Roland In The Caves'') to a white cube with legs (''Roland Goes Square Bashing'') to something resembling Luigi from the [[Mario]] games (''Roland On The Ropes''). Eventually it was decided that Roland should be a squat man in a blue hat, red jumper and yellow trousers. The character was named after Roland Perry, a technical manager at Amstrad. ==Community== The Amstrad CPC enjoyed a strong and long lifetime, mainly due to the machines use for businesses as well as gaming. Dedicated programmers continued working on the CPC range, even producing [[Graphical User Interface]] (GUI) operating systems such as FutureOS and [[SymbOS]]. Internet sites devoted to the CPC have appeared from around the world featuring forums, news, hardware, software, programming and games. CPC [[Computer magazine|Magazines]] appeared during the 1980s including publications in countries such as Britain, France, Spain, Germany, [[Denmark]], [[Australia]] and [[Greece]]. Titles included the official ''[[Amstrad Computer User]]'' publication,<ref name="CPC UK magazines">{{cite web | last = | first = | authorlink = | coauthors = | title =CPC UK Magazines | work = | publisher = Nicholas Campbell | date = | url =http://users.durge.org/~nich/cpcmags/ | format = | doi = | accessdate =2008-05-06 }}</ref> as well as independent titles like ''[[Amstrad Action]]'',<ref name="CPC UK magazines"/> ''[[Amtix!]]'',<ref name="CPC UK magazines"/> ''[[Computing with the Amstrad CPC]]'',<ref name="CPC UK magazines"/> ''[[CPC Attack]]'',<ref name="CPC UK magazines"/> Australia's ''The Amstrad User'', France's ''Amstrad Cent Pour Cent'' and ''Amstar''. Following the CPCs end of production, Amstrad gave permission for the CPC ROMs to be distributed freely as long as the copyright is not changed and that the program acknowledges that Amstrad still holds copyright. This has given people the chance to write programs that [[emulate]] the CPC on other machines including the PC, Amiga and [[Unix]] systems.<ref name="Lawson emulation">{{cite web | last =Lawson | first =Cliff | authorlink = | coauthors = | title =Lawson emulation | work = | publisher =Cliff Lawson | date = | url =http://web.ukonline.co.uk/cliff.lawson/cpchomec.htm | format = | doi = | accessdate =2008-05-06 }}</ref> ==Influence on other Amstrad machines== Amstrad followed their success with the CPC 464 by launching the [[Amstrad PCW]] word-processor range, another Z80-based machine with a 3" disk drive and software by [[Locomotive Software]]. The PCW was originally developed to be compatible with an improved version of the CPC ('ANT', or Arnold Number Two - the CPC's development codename was Arnold). However, Amstrad decided to focus on the PCW, which in due course became vastly successful, and the ANT project never came to market. On [[7 April]] [[1986]] Amstrad announced it had bought from Sinclair Research "...the worldwide rights to sell and manufacture all existing and future Sinclair computers and computer products, together with the Sinclair brand name and those intellectual property rights where they relate to computers and computer related products."<ref>[http://www.crashonline.org.uk/28/news.htm CRASH 28 - News<!-- Bot generated title -->]</ref> which included the ZX Spectrum, for £5 million. This included Sinclair's unsold stock of [[Sinclair QL]]s and Spectrums. Amstrad made more than £5 million on selling these surplus machines alone. Amstrad launched two new variants of the Spectrum: the ZX Spectrum +2, based on the ZX Spectrum 128, with a built-in [[compact audio cassette|tape]] drive (like the CPC 464) and, the following year, the ZX Spectrum +3, with a built-in [[floppy disk]] drive (similar to the CPC 664 and 6128), taking the 3" disks that Amstrad CPC machines used. ==See also== * [[List of Amstrad CPC games]] * [[Amstrad PCW]] (CP/M wordprocessor/personal computer range) * [[CP/M]] * [[Sinclair Research]] * [[ZX Spectrum]] * [[SymbOS]] (multitasking operating system) == Notes and references == {{reflist}} ==External links== {{commons|Amstrad CPC}} * {{Dmoz|Computers/Systems/Amstrad|Amstrad systems}} * {{Dmoz|Computers/Emulators/Amstrad|Amstrad emulators}} [[Category:1984 introductions]] [[Category:Amstrad CPC|*Amstrad CPC]] [[Category:Home computers]] [[ar:أمستراد س ب س]] [[de:Amstrad CPC]] [[es:Amstrad CPC]] [[fr:Amstrad CPC]] [[gl:Amstrad CPC]] [[it:Amstrad CPC]] [[no:Amstrad CPC]] [[pl:Amstrad CPC]] [[pt:Amstrad CPC]] [[ru:Amstrad CPC]] [[fi:Amstrad CPC]] [[sv:Amstrad CPC]]