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Amstrad PCW8512
Amstrad PCW8512
Schneider Joyce
Schneider Joyce

The Amstrad PCW series (Personal Computer Word processor) was British company Amstrad's versatile line of home/personal microcomputers pitched as a complete, integrated home/office solution. A personal computer ( PC) is any Computer whose original sales price size and capabilities make it useful for individuals and which is intended to be operated The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Amstrad is an electronics firm based in Brentwood in Essex, England and founded in 1968 by Sir Alan Michael Sugar in the microcomputer is a Computer with a Microprocessor as its Central processing unit. It was first sold in 1985.

Some models were also affectionately known as Joyce, especially in Germany; the name is that of a secretary of Alan Sugar, the founder of Amstrad, and was the codename of the machine while it was in development. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Sir Alan Michael Sugar (born 24 March 1947 is an English Entrepreneur, Businessman, and Television personality. Amstrad is an electronics firm based in Brentwood in Essex, England and founded in 1968 by Sir Alan Michael Sugar in the

Contents

General features

The PCWs came as complete setups bundled with a full-size word processor keyboard, high resolution monochrome CRT monitor, printers of various types, and floppy disk drive(s). Monochrome comes from the Greek μονόχρωμος ( monochromos) meaning “of one color” which is a combination A floppy disk is an increasingly Obsolete data storage medium that is composed of a disk of thin flexible ("floppy" Magnetic storage medium encased The motherboard and disk drives were incorporated into the casing of the monitor. A motherboard is the central or primary Printed circuit board (PCB making up a complex electronic system such as a modern Computer or Laptop Although it lacked a built-in operating system, the package included bootable floppy disks containing LocoScript word processing software, and the CP/M operating system, including the Mallard BASIC dialect of the BASIC programming language and the Digital Research implementation of Seymour Papert's LOGO programming language. An operating system (commonly abbreviated OS and O/S) is the software component of a Computer system that is responsible for the management and coordination The Word processing software package LocoScript by Locomotive Software was bundled with Amstrad PCW series Z80 -based Microcomputers CP/M (Control Program for Microcomputers is an Operating system originally created for Intel 8080 / 85 based Microcomputers by Gary Kildall Mallard BASIC was a BASIC interpreter for CP/M written by Locomotive Software and supplied with the Amstrad PCW range of In Computer programming, BASIC (an Acronym for Beginner's All-purpose Symbolic Instruction Code) is a family of High-level programming languages Digital Research Inc (aka DR or DRI; originally Intergalactic Digital Research) was the company created by Dr Seymour Papert (born February 29, 1928 in Pretoria South Africa) is an MIT Mathematician, computer scientist, and Logo is a Computer programming language used for Functional programming.

3" drive common on Amstrad machines
3" drive common on Amstrad machines

The floppy disk drives on early models were the relatively obscure 3-inch 'compact floppy' format. A floppy disk is an increasingly Obsolete data storage medium that is composed of a disk of thin flexible ("floppy" Magnetic storage medium encased Later models replaced these with standard 3½" 'microfloppy' drives. A floppy disk is an increasingly Obsolete data storage medium that is composed of a disk of thin flexible ("floppy" Magnetic storage medium encased During the PCWs lifetime, many commercially-produced upgrades were available for the 3" disk models to add one or two 3. 5" drives, either internally or externally. Often these were manually switchable to select which drives were 'A' and 'B'; some even had extra electronics that could do this automatically when the machine was switched on. It is also possible to fit a standard 3. 5" floppy drive as a DIY upgrade; this however requires a number of modifications to the PCW's internal cabling and the external cabinet. Some modern PC floppy drives do not support the control signals that the PCW expects, and this can require extra circuitry or other methods to work around.

In order to allow a bundled printer to be included with every PCW, Amstrad devised a new, lower-level printer control protocol, placing the majority of the printer drive electronics inside the PCW cabinet. Instead of having a relatively sophisticated microcontroller inside the printer casing, the printer consisted only of electromechanical components and high current driver electronics; the power supply was fed from inside the PCW, and pin and motor drive signals were driven by a very small and simple microcontroller on the PCW mainboard. A microcontroller (also MCU or µC is a functional Computer system-on-a- chip. A microcontroller (also MCU or µC is a functional Computer system-on-a- chip. A motherboard is the central or primary Printed circuit board (PCB making up a complex electronic system such as a modern Computer or Laptop Most models of PCW were bundled with a 9-pin dot matrix printer mechanism, with the later 9512 and 9512+ models using a daisywheel (with a different cable; the printers were not interchangeable with the dot matrix models). A dot matrix printer or impact matrix printer refers to a type of Computer printer with a print head that runs back and forth on the page and prints by impact striking A daisy wheel printer is a printing technology which produces high-quality output comparable to that produced by high-end typewriters such as the IBM Selectric. These PCW printers could not, of course, be used on other computers, and the original PCW lacked a then-standard Centronics printer port. Centronics Data Computer Corporation was a pioneering American manufacturer of computer printers now remembered primarily for the parallel interface that bears its name Instead, the Z80 bus and video signals were brought to an edge connector socket at the back of the cabinet. The Zilog Z80 is an 8-bit Microprocessor designed and sold by Zilog from July 1976 onwards An edge connector is the portion of a Printed circuit board consisting of traces leading to the edge of the board that are intended to plug into a matching socket Many accessories including parallel and serial ports were produced for this interface. A parallel port is a type of interface found on Computers ( personal and otherwise for connecting various peripherals In Computing, a serial port is a Serial communication physical interface through which information transfers in or out one Bit at a time (contrast Some of the later models included a built-in parallel port; these could be bundled with either the dedicated Amstrad printer, or a Canon Bubblejet model. A parallel port is a type of interface found on Computers ( personal and otherwise for connecting various peripherals is a Japanese Multinational corporation that specializes in imaging and optical products including Cameras photocopiers and Computer printers Inkjet printers operate by propelling variably-sized droplets of liquid or molten material ( Ink) onto almost any sized page

The machines were built around the 8-bit Zilog Z80 processor, running at 4 MHz, and managed the relatively large amount of RAM main memory using a technique known as bank switching (allowing access to more than the Z80's normal 16-bit address bus reach of 64 kB). Eight-bit CPUs normally use an 8-bit data bus and a 16-bit address bus which means that their Address space is limited to 64 KBs This is not a "natural The Zilog Z80 is an 8-bit Microprocessor designed and sold by Zilog from July 1976 onwards The hertz (symbol Hz) is a measure of Frequency, informally defined as the number of events occurring per Second. Bank switching (also known as "paging" but only loosely related to the ordinary meaning of " Paging " in computing was a technique common in 8-bit An address bus is a Computer bus, controlled by CPUs or DMA -capable Peripherals for specifying the Physical addresses of computer The PCW divided RAM into 16 kB sections, of which four could be accessed at any time. In CP/M, the memory used for the display was switched out while programs were running, giving more than 60 kB of usable RAM. CP/M (Control Program for Microcomputers is an Operating system originally created for Intel 8080 / 85 based Microcomputers by Gary Kildall While the Joyce architecture was designed with configurations of 128 kB and 256 kB of RAM in mind, no PCW was ever sold with 128 kB of RAM.

The PCWs were definitely not designed to play games, although some software authors considered this a minor detail, releasing games like Batman, Head Over Heels, and Bounder. A personal computer Game (also known as a computer game or simply PC game) is a Video game played on a Personal computer, rather Batman from DC Comics has appeared as the main character in a number of Video games created for various platforms for over 20 years Head Over Heels is an Arcade adventure, released in 1987 for several popular 8-bit Home computers and subsequently ported to Bounder is an action game developed and published by Gremlin Graphics in 1986 The PCW video system was not at all suited to games. In order that it be able to display a full 80 column page plus margins, the display's addressable area was 90 columns and the display had 32 lines. The display was, in fact, monochrome and bitmapped, giving a resolution of 720 by 256. Monochrome comes from the Greek μονόχρωμος ( monochromos) meaning “of one color” which is a combination In Computer graphics, a raster graphics image or bitmap, is a Data structure representing a generally rectangular grid of Pixels Even with one bit per pixel, this occupied 23 kB of RAM, making software scrolling far too slow for fluid text manipulation. In Computer graphics, Movies, Television, and other kinetic displays scrolling is sliding text images or video across a monitor or display In order to improve this, the PCW implemented roller RAM, with a 512-byte area of RAM used to hold the address of each line of display data, effectively allowing very rapid scrolling. The video system also fetched data in a special order designed so that plotting a character eight scan lines high would touch eight contiguous addresses. Contiguity is a series of things in continuous connection a grouping of parts in contiguous physical contact This meant that very fast Z80 copy instructions like LDIR could be used. The Zilog Z80 is an 8-bit Microprocessor designed and sold by Zilog from July 1976 onwards Unfortunately, it meant that drawing lines and other shapes could be very complicated.

The original PCW did not have ROM software. On boot, the onboard microcontroller normally used to run the integrated printer was connected to the data port of the main processor, feeding it instructions, allowing it to start running. This code had to be very small in order to fit into the limited ROM of the microcontroller, and as a consequence it has no character generation code; this is why the Amstrad PCW machines do not display text to indicate the loading of software from floppy disk. A floppy disk is an increasingly Obsolete data storage medium that is composed of a disk of thin flexible ("floppy" Magnetic storage medium encased Instead, they display a bright screen which is progressively filled by black stripes as the code is loaded.

The PcW16 does not share any hardware with the original PCW series, other than the Z80 CPU, and should be considered to be a completely different machine.

PCW models

Market impact

The PCW series was extremely successful in addressing its particular market. These machines were not sold as general-purpose computers but rather as simple word processors. They were not bought in preference to a PC or an Amiga; but rather in preference to an electric typewriter. IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. The Amiga is a family of Personal computers originally developed by Amiga Corporation. A typewriter is a mechanical or Electromechanical device with a set of "keys" that when pressed cause characters to be printed on a medium The PCW screen displayed 32 lines with 90 characters each (256 lines of 720 pixels), so more text could appear on a single screen simultaneously than on the 80×25 layout used on other machines.

Despite this they were capable microcomputers which were used for database management, online services, spreadsheets, programming, and even graphics and desktop publishing. The Sage Group's early growth was largely due to the demand for its PCW-based accounts package. The Sage Group plc (abbreviated Sage) is engaged in the development distribution and support of business management software and related products and services for medium-sized and The PCW introduced a generation of British writers to computers who might not have otherwise become involved with them.

See also

External links

The Amstrad CPC is a series of 8-bit Home computers produced by Amstrad Plc during the 1980s and early 1990s SymbOS is a free Multitasking Operating system for Z80 -based 8-bit Computer systems
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