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Amstrad PCW 9256

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Amstrad PCW 9256
Amstrad PCW9256 (service manual cover)
PCW9256 with its keyboard and dot matrix printer, from the cover of Amstrad's service manual
Specifications
ManufacturerAmstrad plc
TypeWord processor and CP/M personal computer
Released1991
CPUZilog Z80A (Z8400APS) at 4 MHz
Memory256 KB (eight KM41C257J-10 DRAMs)
StorageOne 3.5-inch 720 KB drive (UODC-45A); space for a second
DisplayBuilt-in 12-inch paper-white monochrome monitor, 90 × 32 characters
SoundPiezo buzzer
Ports / interfacePrinter and keyboard (DIN sockets)
PowerMains, 93 W maximum; supply in the monitor unit
Dimensions310 × 360 × 350 mm (W × D × H)
Weight14.5 kg
OS / FirmwareLocoScript 1.5, CP/M Plus
PredecessorAmstrad PCW 8256
SuccessorAmstrad PCW 10

The Amstrad PCW 9256 is a Z80 word processor in Amstrad's 1991 PCW range. It has the 256K memory and 9-pin dot matrix printer of the Amstrad PCW 8256, a paper-white screen like the Amstrad PCW 9512, and a 3.5-inch 720K drive in place of the earlier 3-inch drives.[1][2] It was sold alongside the Amstrad PCW 9512+, which has 512K, a parallel port and a daisywheel printer.[2]

History

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Wikipedia dates the PCW 9256 and 9512+ to 1991, when they replaced the PCW 9512.[2] The Amstrad PCW 10 that followed in 1993 is described by some sources as a 9256 with 512K and a parallel port.[2] The software bundle is reported differently: Amstrad's service manual lists LocoScript 1.5 for the 9256, while Wikipedia says it shipped with LocoScript 1.[1][2]

Specification

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PCW9256 technical specification (service manual p. 2)
Item PCW9256
Memory 256K RAM
Disc drive One 3.5-inch 720K drive, with the facility to add a second
Display Paper-white 12-inch monochrome screen, 90 columns by 32 lines
Keyboard Full size, 82 keys
Software LocoScript 1.5, CP/M Plus, Mallard BASIC, GSX, Dr Logo
Printer 9-pin dot matrix, up to 20 cps high quality and 90 cps draft; detachable tractor feed and single-sheet loading. No other printer can be used with the PCW9256.
Size and weight 310 × 360 × 350 mm (W × D × H); 14.5 kg
Power consumption 93 W maximum

Hardware

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Amstrad PCW9256 CPU PCB layout
PCW9256 CPU board MC0127, top view (service manual p. 6)

The 9256 is built from eight boards listed in the parts list: the monitor board MM0059, the CRT board MS0227, the switch board MS0228, a keyboard socket board MS0229, the CPU board MC0127, the printer board MS0231, an AC input board MS0233 and the keyboard's own board MK0011.[1] The main ICs are:[1]

Main ICs (service manual p. 16)
Ref Part Amstrad part no. Notes
IC101 µPD65030GF-044-3B9 (AMS 40028-1) 272769 The PCW 8256 has the Amstrad 40028 at IC101
IC102 Z8400APS 40080 Z80A processor
IC104–111 KM41C257J-10 272770 Eight DRAMs, 256K
IC201 SED9420CAC 171034
IC203 Z765APS 40018 Floppy disc controller
IC301 Amstrad 40027 171043 Keyboard controller
IC401 µPC1379C 272773 Monitor board
IC501 STK7308 170445 Monitor board, power supply
IC502, IC503 AN6531 171041 Monitor board, power supply
IC504 L7824V-SA 177043 Monitor board, power supply
IC701 Amstrad 40026 171038 Printer controller
X101 32.000 MHz crystal 171063

Several parts carry the same Amstrad part numbers as the PCW 8256's: the 40026 printer controller, the 40027 keyboard controller, the STK7308 supply hybrid, the AN6531s, the floppy controller (40018) and the processor (40080). The printer mechanism is the same assembly, part 171127.[1][3]

Disc drive

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The drive is a UODC-45A (part 272508), a 3.5-inch 720K unit.[1] The floppy controller is wired differently from the 8256, 8512 and 9512: John Elliott's notes group the 9256 with the 9512+ and PCW 10, and describe the probe that LocoScript and CP/M versions written after the 9256 use to tell the two controller types apart and to detect whether each drive is 3-inch or 3.5-inch.[4]

Monitor and power supply

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Amstrad PCW9256 monitor PCB layout
Monitor/CRT board, with the mains area outlined (service manual p. 4)

The monitor board carries the switch-mode supply round the STK7308 (IC501) and switching transformer T501, an L7824V regulator (IC504), the deflection circuits and the mains input. The mains fuse F501 is 3.15 A time-lag, 250 V (171531), in holders FH501 and FH502 beside the mains connector; the drawing outlines the area at mains potential. The CRT is a 310GNBWD (272814) and the flyback transformer 2014001.[1] The supply is checked at its 24 V, 12 V and 5 V outputs; the Amstrad PCW 9256 Maintenance Guide gives Amstrad's figures.[1]

Printer and keyboard

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The printer is the 9-pin dot matrix unit of the 8000 series and cannot be replaced by any other printer.[1][2] The printer control circuit is built round the Amstrad 40026 (IC701), with an NE556 (IC702) and two DN8695 drivers (IC706, IC708). Amstrad's drawing of the printer board shows IC702, IC708 and the strobe timing control VR701.[1] The 82-key keyboard has its own board (MK0011) with the 40027 controller and a 5 MHz resonator, and connects by a DIN cord (CD303).[1]

Service documentation

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References

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  1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 Amstrad plc, PCW9256 Personal Computer Word Processor Service Manual. Hosted as File:Amstrad PCW 9256 Service Manual.pdf, described at Amstrad PCW 9256 Service Manual. Technical specification and safety tests p. 2; alignment instructions p. 3; monitor/CRT board layout p. 4; CPU board layout pp. 6–7; electrical parts list pp. 16–17.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Wikipedia, "Amstrad PCW" (revision 1361595210). Retrieved 2026-10-02. The PCW 9256 and 9512+ replacing the 9512 in 1991 with a single 720K 3.5-inch drive; the 9256 with 256K, the dot matrix printer of the 8256 and 8512, and the older LocoScript version 1; the 4 MHz Z80A.
  3. ↑ 3.0 3.1 Amstrad, PCW 8256/8512 Personal Computer Word Processor Service Manual. Hosted as File:Amstrad PCW 8000 Series Service Manual.pdf, described at Amstrad PCW 8256 / PCW 8512 Service Manual. Electrical parts lists pp. 33–34 (PDF pp. 34–35); printer mechanical parts list p. 30 (PDF p. 31), printer mechanical assembly 171127.
  4. ↑ 4.0 4.1 John Elliott, PCW Hardware. Hosted as File:PCW Hardware Reference (John Elliott).pdf, described at Amstrad PCW Hardware Reference (John Elliott). Section 2 (boot process), section 6.1 (the PCW8256/8512/9256/10 printer controller), sections 8.2–8.3 (drive decoding on the 9256, 9512+ and 10, and the controller probe).