PPC 512
Encyclopedia
The Amstrad PPC512 and Amstrad PPC640 were the first portable IBM PC compatible
IBM PC compatible
IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...

 computers made by Amstrad
Amstrad
Amstrad is a British electronics company, now wholly owned by BSkyB. As of 2006, Amstrad's main business is manufacturing Sky Digital interactive boxes....

. They were a development of the desktop PC-1512
PC-1512
The Amstrad PC1512 was Amstrad's mostly IBM PC-compatible computer system, first manufactured in 1986. It was later succeeded by the PC1640.It launched for £499 and sold very well, as it was one of the first cheap PCs in Europe...

 and PC-1640 models. As portable computers, they contained all the elements necessary to perform computing on the move. They had a keyboard and a monochrome LCD display built in and also had space for disposable batteries to power the PC where a suitable alternative power source (i.e. mains or 12 volt vehicle power) was not available. The PCs came with either one or two double density double side floppy disc drives and the PPC640 model also featured a modem. Both models were supplied with 'PPC Organiser' software and the PPC640 was additionally supplied with the 'Mirror II' communications software.

Hardware

The two computers had very similar specifications. The PPC512 had an NEC V30 processor running at 8MHz, 512 KiB
Kibibyte
The kibibyte is a multiple of the unit byte for quantities of digital information. The binary prefix kibi means 1024; therefore, 1 kibibyte is . The unit symbol for the kibibyte is KiB. The unit was established by the International Electrotechnical Commission in 1999 and has been accepted for use...

 of memory, a full-size 102-key keyboard, a built-in liquid crystal display
Liquid crystal display
A liquid crystal display is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals . LCs do not emit light directly....

 (not backlit) that could emulate the CGA
Color Graphics Adapter
The Color Graphics Adapter , originally also called the Color/Graphics Adapter or IBM Color/Graphics Monitor Adapter, introduced in 1981, was IBM's first color graphics card, and the first color computer display standard for the IBM PC....

 or MDA
Monochrome Display Adapter
The Monochrome Display Adapter introduced in 1981 was IBM's standard video display card and computer display standard for the PC. The MDA did not have any pixel-addressable graphics modes...

 and either one or two 720k 3.5" floppy drives (the model was either the PPC512S or PPC512D depending on the number of drives it had). The PPC640 was otherwise identical except that it had 640 KiB
Kibibyte
The kibibyte is a multiple of the unit byte for quantities of digital information. The binary prefix kibi means 1024; therefore, 1 kibibyte is . The unit symbol for the kibibyte is KiB. The unit was established by the International Electrotechnical Commission in 1999 and has been accepted for use...

 of memory, a built-in modem
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...

, and its case was a darker shade of grey.

The PPC included standard connectors for RS-232
RS-232
In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...

, Centronics and CGA/MDA video, allowing existing peripherals to be used. All the signals used by the 8-bit ISA bus were also available through an expansion connector.

Four possible power sources could be used:
  • Ten C-size alkaline batteries. (10 x 1.5v = 15 volts, but the load was such the voltage dropped to nearer 12 volts in use.)

  • Mains adaptor
  • Car cigarette lighter
    Cigar lighter receptacle
    The cigarette lighter receptacle in an automobile, initially designed to power an electrically heated lighter, became a de-facto standard DC connector to supply electrical power for portable accessories used in or near an automobile...

    .
  • An Amstrad PC-MD, PC-CD or PC-ECD Monitor. (These monitors all contained a power supply)


The physical layout of the components was unlike most laptop designs: instead of the lid containing the screen, it contained the keyboard. The hinges were therefore at the front of the main unit, rather than the back. The LCD was hinged separately and folded down into a recess on the top of the system unit. The one or two floppy drives were located on the right-hand side. When closed, the size of the PPC was 45cm wide × 10cm high × 23cm deep.

A bank of six DIP switch
DIP switch
DIP switches are manual electric switches that are packaged in a group in a standard dual in-line package...

es was used to select whether the video hardware emulated CGA or MDA, and whether to use an internal or external monitor.

No official hard drive option or docking station was manufactured, but both were sold by third-party manufacturers.

Software

MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...

 3.3 was supplied with all PPCs, along with 'Organizer' - a memory-resident suite of utilities including a card file, diary, calculator and telephone dialler. In addition, the PPC 640 was supplied with Mirror II, a communications package for use with the built-in modem.

The MS-DOS boot disk also included a utility which could be used to switch between the internal display and an external monitor without rebooting.

Amstrad PC20 / Sinclair PC200

In late 1988 Amstrad created a desktop computer based on the PPC design, intended for the home market. The LCD was replaced by an RF modulator
RF modulator
An RF modulator is a device that takes a baseband input signal and outputs a radio frequency-modulated signal....

 to display CGA video on a domestic television, and the keyboard and system unit were combined in an integrated case similar to the original Atari ST
Atari ST
The Atari ST is a home/personal computer that was released by Atari Corporation in 1985 and commercially available from that summer into the early 1990s. The "ST" officially stands for "Sixteen/Thirty-two", which referred to the Motorola 68000's 16-bit external bus and 32-bit internals...

 or the Amiga 500
Amiga 500
The Amiga 500 - also known as the A500 - was the first “low-end” Commodore Amiga 16/32-bit multimedia home/personal computer. It was announced at the winter Consumer Electronics Show in January 1987 - at the same time as the high-end Amiga 2000 - and competed directly against the Atari 520ST...

. The second floppy drive bay was replaced by two ISA slots, though the design of the case was such that any cards fitted would protrude from the top of the computer. The PC200 had a black case and 'Sinclair' branding, while the PC20 was white and branded 'Amstrad'; the two were otherwise identical.

In addition to MS-DOS 3.3 and Organizer, the PC20/PC200 was supplied with GEM
Graphical Environment Manager
GEM was a windowing system created by Digital Research, Inc. for use with the CP/M operating system on the Intel 8088 and Motorola 68000 microprocessors...

 and four CGA-compatible games.

The graphical capabilities (CGA) and sound output (PC speaker
PC speaker
A PC speaker is a loudspeaker, built into some IBM PC compatible computers. The first IBM Personal Computer, model 5150, employed a standard 2.25 inch magnetic driven speaker. More recent computers use a piezoelectric speaker instead. The speaker allows software and firmware to provide...

) were greatly inferior compared to other home computers of the time. Consequently, the PC20/PC200 was not a commercial success.

Although the PC20/PC200 does not support today's floppy disk drives through the built-in FDD connector, it uses a compatible floppy disk controller (Zilog Z765a) that can work after modification of the FDD connector, though only with 720k disks.
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