Josh: New page: PCW 9256 from Amstrad's service manual

2026-10-02T05:54:12Z

New page: PCW 9256 from Amstrad's service manual

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{{Infobox computer
| name = Amstrad PCW 9256
| image = [[File:Amstrad PCW9256 (service manual cover).png|260px|frameless]]
| caption = PCW9256 with its keyboard and dot matrix printer, from the cover of Amstrad's service manual
| manufacturer = Amstrad plc
| type = Word processor and CP/M personal computer
| release_date = 1991
| cpu = Zilog Z80A (Z8400APS) at 4 MHz
| memory = 256 KB (eight KM41C257J-10 DRAMs)
| storage = One 3.5-inch 720 KB drive (UODC-45A); space for a second
| display = Built-in 12-inch paper-white monochrome monitor, 90 × 32 characters
| sound = Piezo buzzer
| ports = Printer and keyboard (DIN sockets)
| power = Mains, 93 W maximum; supply in the monitor unit
| os = LocoScript 1.5, CP/M Plus
| dimensions = 310 × 360 × 350 mm (W × D × H)
| weight = 14.5 kg
| predecessor = [[Amstrad PCW 8256]]
| successor = [[Amstrad PCW 10]]
}}
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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.<ref name="sm9256">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.</ref><ref name="wppcw">Wikipedia, [https://en.wikipedia.org/wiki/Amstrad_PCW "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.</ref> It was sold alongside the [[Amstrad PCW 9512+]], which has 512K, a parallel port and a daisywheel printer.<ref name="wppcw" />

== History ==
Wikipedia dates the PCW 9256 and 9512+ to 1991, when they replaced the PCW 9512.<ref name="wppcw" /> The [[Amstrad PCW 10]] that followed in 1993 is described by some sources as a 9256 with 512K and a parallel port.<ref name="wppcw" /> 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.<ref name="sm9256" /><ref name="wppcw" />

== Specification ==
{| class="wikitable styled-table" style="width:70%; text-align:left;"
|+'''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 ==
[[File:Amstrad PCW9256 CPU PCB layout.png|thumb|right|300px|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.<ref name="sm9256" /> The main ICs are:<ref name="sm9256" />

{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''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.<ref name="sm9256" /><ref name="sm8">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.</ref>

=== Disc drive ===
The drive is a UODC-45A (part 272508), a 3.5-inch 720K unit.<ref name="sm9256" /> 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.<ref name="jehw">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).</ref>

=== Monitor and power supply ===
[[File:Amstrad PCW9256 monitor PCB layout.png|thumb|right|250px|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.<ref name="sm9256" /> The supply is checked at its 24 V, 12 V and 5 V outputs; the [[Amstrad PCW 9256 Maintenance Guide]] gives Amstrad's figures.<ref name="sm9256" />

=== Printer and keyboard ===
The printer is the 9-pin dot matrix unit of the 8000 series and cannot be replaced by any other printer.<ref name="sm9256" /><ref name="wppcw" /> 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.<ref name="sm9256" /> 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).<ref name="sm9256" />

== Service documentation ==
* [[Amstrad PCW 9256 Service Manual]]: specification, alignment, board layouts, schematics and the electrical parts list. It has no floppy drive section and no fault-finding procedure.<ref name="sm9256" />
* [[Amstrad PCW Hardware Reference (John Elliott)]]: ports, the boot process, the printer controller and the floppy controller probe.<ref name="jehw" />
* [[Amstrad PCW 8256 / PCW 8512 Service Manual]]: the printer mechanism parts list for the shared dot matrix printer.<ref name="sm8" />

== Related pages ==
* [[Amstrad PCW 9256 Maintenance Guide]] · [[Amstrad PCW 9256 Troubleshooting Guide]] · [[Amstrad PCW 9256 Capacitor Replacement Guide]]
* [[Amstrad PCW 9512+]] · [[Amstrad PCW 10]] · [[Amstrad PCW 8256]]
* [[Floppy Drive Repair]] · [[CRT Discharge Procedure]]

== References ==
<references />

{{Navbox-Amstrad|state=collapsed}}

[[Category:Amstrad]]

Amstrad PCW 9256 - Revision history

Josh: New page: PCW 9256 from Amstrad's service manual