Amstrad CPC
Keyboard |
The Amstrad CPC (short for "Colour Personal Computer") is a series of
The series spawned a total of six distinct models: The CPC 464, CPC 664, and CPC 6128 were highly successful competitors in the European home computer market. The later 464 plus and 6128 plus, intended to prolong the system's lifecycle with hardware updates, were considerably less successful, as was the attempt to repackage the plus hardware into a game console as the GX4000.
The CPC models' hardware is based on the
The CPC series was pitched against other home computers primarily used to play video games and enjoyed a strong supply of game software. The comparatively low price for a complete computer system with dedicated monitor, its high-resolution monochrome text and graphic capabilities and the possibility to run CP/M software also rendered the system attractive for business users, which was reflected by a wide selection of application software.
During its lifetime, the CPC series sold approximately three million units.[3]
Models
The original range
The philosophy behind the CPC series was twofold, firstly the concept was of an "all-in-one", where the computer, keyboard and its data storage device were combined in a single unit and sold with its own dedicated display monitor. Most home computers at that time such as ZX Spectrum series, Commodore 64, and BBC Micro relied on the use of the domestic television set and a separately connected tape recorder or disk drive. In itself, the all-in-one concept was not new, having been seen before on business-oriented machines and the Commodore PET.
Secondly, Amstrad founder Alan Sugar wanted the machine to resemble a "real computer, similar to what someone would see being used to check them in at the airport for their holidays",[4] and for the machine to not look like "a pregnant calculator"[5] – in reference presumably to the ZX81 and ZX Spectrum with their low cost, membrane-type keyboards.
CPC 464
The CPC 464 was one of the most successful computers in Europe and sold more than two million units.[6]
The CPC 464 featured 64 KB RAM and an internal cassette deck. It was introduced in June 1984 in the UK. Initial suggested retail prices for the CPC 464 were £249.00/DM899.00 with a green screen and £359.00/DM1398.00 with a colour monitor. Following the introduction of the CPC 6128 in late 1985, suggested retail prices for the CPC 464 were cut by £50.00/DM100.00.
In 1990, the 464plus replaced the CPC 464 in the model line-up, and production of the CPC 464 was discontinued.
CPC 664
The CPC 664 features 64 KB RAM and an internal 3-inch floppy disk drive. It was introduced on 25 April 1985 in the UK.[7] Initial suggested retail prices for the CPC 664 were £339.00/DM1198.00 with a green screen and £449.00/DM1998.00 with a colour monitor.
After the successful release of the CPC 464, consumers were constantly asking for two improvements: more memory and an internal disk drive. For Amstrad, the latter was easier to realise. At the deliberately low-key introduction of the CPC 664, the machine was positioned not only as the lowest-cost disk system but even the lowest-cost CP/M 2.2 machine. In the Amstrad CPC product range the CPC 664 complemented the CPC 464 which was neither discontinued nor reduced in price.[8]
Compared to the CPC 464, the CPC 664's main unit has been significantly redesigned, not only to accommodate the floppy disk drive but also with a redesigned keyboard area. Touted as "ergonomic" by Amstrad's promotional material, the keyboard is noticeably tilted to the front with MSX-style cursor keys above the numeric keypad. Compared to the CPC 464's multicoloured keyboard, the CPC 664's keys are kept in a much quieter grey and pale blue colour scheme.
The back of the CPC 664 main unit features the same connectors as the CPC 464, with the exception of an additional 12V power lead. Unlike the CPC 464's cassette tape drive that could be powered off the main unit's 5V voltage, the CPC 664's floppy disk drive requires an additional 12V voltage. This voltage had to be separately supplied by an updated version of the bundled green screen/colour monitor (GT-65 and CTM-644 respectively).
The CPC 664 was only produced for approximately six months. In late 1985, when the CPC 6128 was introduced in Europe, Amstrad decided not to keep three models in the line-up, and production of the CPC 664 was discontinued.[9]
CPC 6128
The CPC 6128 features 128 KB RAM and an internal 3-inch floppy disk drive. Aside from various hardware and firmware improvements, one of the CPC 6128's most prominent features is the compatibility with the CP/M+ operating system that rendered it attractive for business uses.
The CPC 6128 was released on 13 June 1985 and initially only sold in the US.[7] Imported and distributed by Indescomp, Inc. of Chicago, it was the first Amstrad product to be sold in the United States, a market that at the time was traditionally hostile towards European computer manufacturers.[10] Two months later, on 15 August 1985, it arrived in Europe[7] and replaced the CPC 664 in the CPC model line-up. Initial suggested retail prices for the CPC 6128 were US$699.00/£299.00/DM1598.00 with a green screen and US$799.00/£399.00/DM2098.00 with a colour monitor.
In 1990, the 6128plus replaced the CPC 6128 in the model line-up, and production of the CPC 6128 was discontinued.
The plus range
In 1990, confronted with a changing home computer market, Amstrad decided to refresh the CPC model range by introducing a new range variantly labelled plus or PLUS, 1990, or CPC+ range. The main goals were numerous enhancements to the existing CPC hardware platform, to restyle the casework to provide a contemporary appearance, and to add native support of cartridge media. The new model palette includes three variants, the 464plus and 6128plus computers and the GX4000 video game console. The "CPC" abbreviation was dropped from the model names.
The redesign significantly enhanced the CPC hardware, mainly to rectify its previous shortcomings as a gaming platform. The redesigned video hardware allows for
The new range of models was intended to be completely
Despite the significant hardware enhancements, many viewed it as outdated, being based on an 8-bit CPU, and it failed to attract both customers and software producers who were moving towards systems such as the
464 plus, 6128 plus
The 464 plus and 6128 plus models were intended as "more sophisticated and stylish" replacements of the CPC 464 and CPC 6128. Based on the redesigned plus hardware platform, they share the same base characteristics as their predecessors: The 464 plus is equipped with 64 KB RAM and a cassette tape drive, the 6128 plus features 128 KB RAM and a 3" floppy disk drive. Both models share a common case layout with a keyboard taken over from the CPC 6128 model, and the respective mass storage drive inserted in a case breakout.
In order to simplify the EMC screening process, the edge connectors of the previous models have been replaced with micro-ribbon connectors as previously used on the German Schneider CPC 6128. As a result, a wide range of extensions for the original CPC range are connector-incompatible with the 464 plus and 6128 plus. In addition, the 6128plus does not have a tape socket for an external tape drive.
The plus range is not equipped with an on-board ROM, and thus the 464 plus and the 6128 plus do not contain a firmware. Instead, Amstrad provided the firmware for both models via the
Both the 464 plus and the 6128 plus were introduced to the public in September 1990. Initial suggested retail prices were £229/1,990 F with a monochrome monitor and £329/2,990 F with a colour monitor for the 464 plus, and £329/2,990 F with a monochrome monitor and £429/3,990 F with a colour monitor for the 6128plus.[14]
GX4000
Developed as part of the plus range, the GX4000 was Amstrad's short-lived attempt to enter the video game consoles market. Sharing the plus range's enhanced hardware characteristics, it represents the bare minimum variant of the range without a keyboard or support for mass storage devices.
Special models and clones
CPC 472
During the August holidays of 1985, Spain briefly introduced an import tax of 15 000 pesetas (€90.15) on computers containing 64 KB or less of RAM (Royal Decree 1215/1985
KC compact
The
Aleste 520EX
In 1993, Omsk, Russia based company Patisonic released the Aleste 520EX, a computer highly compatible with the Amstrad CPC 6128.[21][22][23] It could also be switched into an MSX mode. An expansion board named Magic Sound allowed to play Scream Tracker files.
Reception
A
Hardware
Processor
The entire CPC series is based on the Zilog Z80; a processor, clocked at 4 MHz.[25]
In order to avoid the CPU and the video logic simultaneously accessing the shared main memory and causing video corruption ("snowing"), CPU memory access is constrained to occur on
Memory
Amstrad CPCs are equipped with either 64 (CPC 464, CPC 664, 464plus, GX4000) or 128 (CPC 6128, 6128plus) KB of RAM.[25][27] This base memory can be extended by up to 512 KB using memory expansions sold by third-party manufacturers, and by up to 4096 KB using experimental methods developed by hardware enthusiasts. Because the Z80 processor is only able to directly address 64 KB of memory, additional memory from the 128 KB models and memory expansions is made available using bank switching.
Video
Underlying a CPC's video output is the unusual pairing of a
Three built-in display resolutions are available: 160×200 pixels with 16 colours ("Mode 0", 20 text columns), 320×200 pixels with 4 colours ("Mode 1", 40 text columns), and 640×200 pixels with 2 colours ("Mode 2", 80 text columns).[25] Increased screen size can be achieved by reprogramming the CRTC.
The original CPC video hardware supports a
With the exception of the GX4000, all CPC models lack an RF television or composite video output and instead shipped with a 6-pin RGB DIN connector, also used by Acorn computers, to connect the supplied Amstrad monitor.[25] This connector delivers a 1v p-p analogue RGB with a 50 Hz composite sync signal that, if wired correctly, can drive a 50 Hz SCART television. External adapters for RF television were available as a first-party hardware accessory.
Audio
The CPC uses the General Instrument AY-3-8912 sound chip,[25] providing three channels, each configurable to generate square waves, white noise or both. A small array of hardware volume envelopes are available.
Output is provided in mono by a small (4 cm) built-in loudspeaker with volume control, driven by an internal amplifier. Stereo output is provided through a 3.5 mm headphones jack.
It is possible to play back
Floppy disk drive
Amstrad uses
The interface with the drives is an NEC 765
Discs 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 inch diskettes, and designed to be mailed without any additional packaging[citation needed]. 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. They were significantly more expensive than both 5.25 inch and 3.5 inch 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-inch machines (the PCW and the 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 machines. They also found use on embedded systems.
The
The 3-inch disks themselves are usually known as "discs" on the CPC, following the spelling on the machine's plastic casing and conventional
Expansion
The hardware and firmware was designed to be able to access software provided on external ROMs. Each ROM has to be a 16 KB block and is switched in and out of the memory space shared with the video RAM. The Amstrad firmware is deliberately designed so that new software could be easily accessed from these ROMs. Popular applications were marketed on ROM, particularly word processing and programming utility software (examples are Protext and Brunword of the former, and the MAXAM assembler of the latter type).
Such extra ROM chips do not plug directly into the CPC itself, but into extra plug-in "rom boxes" which contain 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 on ROM loads much faster than from disc or tape and the machine's boot-up sequence was designed to evaluate ROMs it found and optionally hand over control of the machine to them. This allows significant customisation of the functionality of the machine, something that enthusiasts exploited for various purposes.[28] However, the typical users would probably not be aware of this added ROM functionality unless they read the CPC press, as it is not described in the user manual and was hardly ever mentioned in marketing literature. It is, however, documented in the official Amstrad firmware manual.
The machines also feature a 9-pin Atari joystick port that will either directly take one joystick, or two joysticks by use of a splitter cable.[25]
Peripherals
RS232 serial adapters
Amstrad issued two RS-232-C D25 serial interfaces, attached to the expansion connector on the rear of the machine, with a through-connector for the CPC 464 disk drive or other peripherals.
The original interface came with a Book of Spells for facilitating data transfer between other systems using a proprietary
Software and hardware limitations in this interface led to its replacement with an Amstrad-branded version of a compatible alternative by
Software
BASIC and operating system
Like most home computers at the time, the CPC has its OS and a BASIC interpreter built in as ROM. It uses Locomotive BASIC - an improved version of Locomotive Software's Z80 BASIC for the BBC Micro co-processor board. It is particularly notable for providing easy access to the machine's video and audio resources in contrast to the POKE commands required on generic Microsoft implementations. Other unusual features include timed event handling with the AFTER and EVERY commands, and text-based windowing.
CP/M
Digital Research's CP/M operating system was supplied with the 664 and 6128 disk-based systems, and the DDI-1 disk expansion unit for the 464. 64k machines shipped with CP/M 2.2 alone, while the 128k machines also include CP/M 3.1. The compact CP/M 2.2 implementation is largely stored on the boot sectors of a 3" disk in what was called "System format"; typing |CPM from Locomotive BASIC would load code from these sectors, making it a popular choice for custom game loading routines. The CP/M 3.1 implementation is largely in a separate file which is in turn loaded from the boot sector. Much public domain CP/M software was made available for the CPC, from word-processors such as VDE to complete bulletin board systems such as ROS.
Other languages
Although it was possible to obtain compilers for Locomotive BASIC,
Roland
In an attempt to give the CPC a recognisable mascot, a number of games by Amstrad's in-house software publisher
Schneider Computer Division
In order to market its computers in Germany, Austria, and Switzerland where Amstrad did not have any distribution structures, Amstrad entered a partnership with
Although they are based on the same hardware, the Schneider CPC models differ from the Amstrad CPC models in several details. Most prominently, the Schneider CPC 464 and CPC 664 keyboards featured grey instead of coloured keys, but still in the original British keyboard layout. To achieve a German "
In 1988, after Schneider refused to market Amstrad's AT-compatible computer line, the cooperation ended. Schneider went on to sell the remaining stock of Schneider CPC models and used their now well-established market position to introduce its own PC designs. With the formation of its German daughter company Amstrad GmbH to distribute its product lines including the CPC 464 and CPC 6128, Amstrad attempted but ultimately failed to establish their own brand in the German-speaking parts of Europe.[30][31]
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
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 partly compatible with an improved version of the CPC (ANT, or Arnold Number Two - the CPC's development codename was Arnold).[34][35] However, Amstrad decided to focus on the PCW, and the ANT project never came to market.
On 7 April 1986, Amstrad announced it had bought from
Production Timeline
See also
- Amstrad CPC character set
- Amstrad CP/M Plus character set
- List of Amstrad CPC emulators
- List of Amstrad CPC games
- GX4000
- SymbOS (multitasking operating system)
Notes and references
- ^ Transistorized memory, such as RAM, ROM, flash and cache sizes as well as file sizes are specified using binary meanings for K (10241), M (10242), G (10243), etc.
- ^ CPC464 User Manual, p. 11, Amstrad Consumer Electronics Plc.
- ^ "Amstrad Product Archive". Archived from the original on 9 May 2008. Retrieved 25 September 2009.
- ISBN 978-1-84454-891-0.
- ISBN 978-0-230-74933-7.
- ^ "OLD-COMPUTERS.COM : The Museum". www.old-computers.com. Archived from the original on 25 March 2019. Retrieved 27 June 2016.
- ^ a b c "Special Feature: Happy Birthday!". Popular Computing Weekly. 1 May 1987. pp. 14–18 (18).
- ^ The CPC664, Amstrad Computer User May 1985, P. 42-46.
- ^ "Interview de M. Roland Perry" (in French). Amstrad Forever. Archived from the original on 20 July 2011. Retrieved 2 April 2010.
- ^ Amstrad Computer User, "User News...", August 1985, p. 7.
- ^ a b c d Lawson, Cliff. "Arnold "V" Specification 1.4". Amstrad. Archived from the original on 18 November 2000.
- ^ Retro Gamer issue 83, From the Archives: Radical Software
- ^ "Amstrad System Cartridges". grimware.org. Archived from the original on 1 February 2010. Retrieved 22 March 2010.
- ^ Paris in the Spring, Amstrad Action Issue 60, September 1990, P. 34-36
- ^ "BOE.es - BOE-A-1985-15514 Real Decreto 1215/1985, de 17 de julio, por el que se modifican determinadas subpartidas del arancel de Aduanas". www.boe.es (in Spanish).
- ^ "BOE.es - BOE-A-1985-18847 Real Decreto 1558/1985, de 28 de agosto, por el que se aclara el alcance del mínimo específico introducido en la subpartida 84.53.B.II del Arancel de Aduanas, por el Real Decreto 1215/1985". www.boe.es (in Spanish).
- ^ "BOE.es - BOE-A-1985-15611 Real Decreto 1250/1985, de 19 de junio, por el que se establece la sujeción a especificaciones técnicas de los terminales de pantalla con teclado, periféricos para entrada y representación de información en equipo de proceso de datos". www.boe.es (in Spanish).
- ^ "CPC472". CPCWiki. Retrieved 17 August 2011.
- ^ "KC Compact Documentation". Archived from the original on 20 February 2022. Retrieved 11 February 2023.
- ^ "JKCEMU - Kleincomputer-Emulator (in German)". www.jens-mueller.org. Retrieved 6 March 2023.
- ^ "Aleste 520EX - CPCWiki". www.cpcwiki.eu.
- ^ "Aleste 520EX". aleste520.narod.ru.
- ^ "Spanish page". Archived from the original on 13 March 2016. Retrieved 10 January 2015.
- ^ a b Pountain, Dick (January 1985). "The Amstrad CPC 464". BYTE. Vol. 10, no. 1. pp. 401–407. Retrieved 9 January 2015.
- ^ a b c d e f g Technical Specification, CPC464 Service Manual, p. 2., Amstrad Consumer Electronics Plc.
- ^ CPC464/664/6128 Firmware (Soft 968), Section 1
- ^ a b c Technical Specification, CPC6128 Service Manual, p. 31., Amstrad Consumer Electronics Plc.
- ^ "ROM :: Amstrad CPC -- 8bit Projects For Everyone". 8bit.yarek.pl. Archived from the original on 8 August 2009. Retrieved 1 November 2009.
- ^ CPC Schneider International 6/85, P. 7
- ^ CeBIT '88, Schneider Magazin 5/88, P. 6-8
- ^ "Defunct Audio Manufacturers". Retrieved 20 September 2009.
- ^ a b c d e "CPC UK Magazines". Nicholas Campbell. Archived from the original on 31 October 2001. Retrieved 6 May 2008.
- ^ Lawson, Cliff. "Lawson emulation". Cliff Lawson. Archived from the original on 10 May 2008. Retrieved 6 May 2008.
- ^ Smith, Tony (12 February 2014). "You're NOT fired: The story of Amstrad's amazing CPC 464". www.theregister.co.uk. Retrieved 20 December 2018.
- ^ "The CPC that never was". Retro Gamer. 28 December 2017.
- ^ "CRASH 28 - News". www.crashonline.org.uk.
External links
- CPC-Wiki (CPC specific Wiki containing further information)
- Unofficial Amstrad WWW Resource
- Amstrad systems at Curlie
- New OS for the CPC