MACHINE REFERENCE

Amstrad PC1512

The Amstrad PC1512 went on sale at £399 plus VAT in September 1986, undercutting a genuine IBM PC by well over a thousand pounds and putting a real MS-DOS machine, monitor and keyboard included, within reach of an ordinary household for the first time in Britain. Lift the monitor off its stand and you'd find the whole power supply sitting under it, four AA batteries wedged in beside it to keep the clock running, an odd bit of engineering that meant the "computer" on the desk was, electrically speaking, only half the machine.

Why it matters

Amstrad's trick, learned from selling hi-fi separates and repeated with the CPC range, was to sell a complete working system at one fixed price rather than a box you then had to fit a graphics card, serial port and monitor to yourself. Applied to the IBM-compatible market that idea worked: at its peak Amstrad held around a quarter of the European PC market, and the newly launched PC Plus magazine aimed its early issues specifically at 1512 owners and compatible clones because so many readers owned one. The hardware was nothing special even in 1986: an 8086-2 at 8MHz and CGA-level graphics. What clone-builders and business buyers had to answer was the price of a complete, working PC.

What to check before you buy

  • Confirm the original monitor is present and working. The PSU lives inside it, so without it the system unit won't power on at all.
  • Check whether the four AA batteries under the monitor have been removed; leaked cells corrode the holder and the real-time clock chip.
  • Test the keyboard for a stuck key before assuming a fault elsewhere. A jammed key drops the machine into an endless beep loop at boot.
  • The keyboard and mouse use Amstrad's own connectors, not standard PC ones, so a complete system needs its original peripherals or period-correct replacements.
  • Ask whether the CPU has been swapped for an NEC V30, a common and easily reversible upgrade from the period.
  • The 5.25-inch floppy drives are pushing 40 years old; expect to clean or re-lubricate them before trusting any disk read or write.
Amstrad PC1512

Photo: M ralser, Wikimedia Commons (CC BY-SA 4.0)

Released

1986

RAM

512KB on-board with parity, expandable to 640KB via 32KB add-on blocks

CPU

Intel 8086-2, 8MHz (socketed; commonly upgraded to an NEC V30)

Launch price

£399 plus VAT for the base mono single-floppy model, up to £949 plus VAT for the colour 20MB hard disk model (sources give slightly different ranges)

Manufacturer

Amstrad

Form factor

Desktop system unit with separate keyboard and monitor (monitor houses the power supply)

CPU

Intel 8086-2, 8MHz (socketed; commonly upgraded to an NEC V30)

Chipset

No single branded chipset: custom Amstrad gate-array logic plus standard support ICs: Intel 8237-4 DMA controller, 8259A-2 interrupt controller, 8253 PIT, NEC uPD765A floppy controller, HD146818 real-time clock, INS8250 UART

RAM

512KB on-board with parity, expandable to 640KB via 32KB add-on blocks

ROM

16KB system ROM (custom BIOS written by MEJ Electronics, not copied from IBM)

Graphics

CGA-compatible custom video circuit built around a partially emulated Motorola MC6845 CRTC; 640×200 16-colour mode; 16KB video RAM expandable to 64KB

Audio

PC speaker only, driven from the 8253 PIT; no dedicated sound chip

Storage

One or two 360KB 5.25-inch floppy drives; optional 10MB or 20MB hard disk

Ports

RS232 serial (25-pin D), Centronics parallel (25-pin D), Atari/Spectrum-compatible joystick port (9-pin D), dedicated mouse port (9-pin D), keyboard (6-pin DIN), video out to monitor (8-pin DIN), light pen (6-pin berg strip), three 16-bit ISA expansion slots

OS

MS-DOS 3.2 bundled with Digital Research GEM Desktop and DOS Plus; Locomotive/Mallard BASIC also supplied

PSU

External, built into the monitor unit, fed to the system box over a 14-pin DIN cable; the base unit has no power supply of its own

Units sold

Not precisely documented. Amstrad reportedly held around 25% of the European PC market at its peak with the PC1512/1640 range

Successors

Amstrad PC1640 (1987), later the AT-class PC2000 series (e.g. PC2286)

  • Power supply lives in the monitor
    The system unit has no PSU of its own. Power comes from a unit built into Amstrad's own monitor and reaches the base over a 14-pin DIN cable, so a dead monitor takes the whole computer down with it.
  • Stuck key halts boot
    A jammed or sticking key on the dedicated Amstrad keyboard fails the keyboard interface test during boot, sending the machine into a repeating short-beep loop instead of starting.
  • RTC/CMOS battery corrosion
    The real-time clock is backed by four ordinary AA cells under the monitor; left in place for decades they leak and corrode the battery holder and clock chip, producing "RTC failure" messages at boot.
    Vogons: AMSTRAD PC 1512 RTC Failure →
  • 1986 Announced and launched 2 September at the Queen Elizabeth II Conference Centre in London, also sold in West Germany as the Schneider PC1512
  • 1986 Ships with a fanless case; rumours of overheating in hard-disk models circulate despite no confirmed fault, prompting Alan Sugar's public "I'll stick a bloody fan in it" response
  • 1987 Amstrad PC1640 launched with 640KB RAM and Paradise EGA-compatible graphics; other markets get the PC6400 and Sinclair PC500 variants
  • 1987 Case redesigned (lighter grey textured plastic, red logo, added ventilation) alongside a revised BIOS
  • 1988 Amstrad moves on to the AT-class PC2000 series as the 1512/1640 line is phased out