Editing Amstrad PCW 8256 / PCW 8512 Service Manual

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The '''''PCW 8256/8512 Personal Computer Word Processor Service Manual''''' is Amstrad Consumer Electronics plc's service manual for the PCW 8256 and PCW 8512, with a cover price of £8.00. It is undated and has no contents page or part number. The hosted scan has 42 PDF pages and the Internet Archive's OCR text layer: the 34 numbered pages, three chassis schematic sheets, three printer circuit diagram sheets and a repeat of the notes to service engineers. Amstrad published no separate "PCW 8000 Series" manual; the file name comes from the Internet Archive item.

== Contents ==
The manual has no contents list. Its pages, with the printed page numbers (PDF pages in brackets where they differ):
* 1 cover; 2 safety test and specification; 3 important notes to service engineers; 4 software errors
* 5-9 diagnostic flow charts for drives FD1 and FD2: motor rotation, read error, write error, and seek error (FD2 only)
* 10 drive mechanism drawing; 11 notice that the next four pages are for information only
* 12-14 alignment checks: index burst, amplitude ratio, track 00 to 39 timing, positioning with a CE disk
* 15 FD1 schematic diagram; 16 FD2 schematic diagram
* 17 alignment chart for the monitor
* 18-19 monitor schematic diagram (PDF 18-20, split across three images)
* 20 monitor PCB, marked "danger mains voltage" (PDF 21); 21 monitor PCB component layout (PDF 22)
* 22-23 mechanical exploded view, cabinet exploded view and cabinet parts list (PDF 23-24)
* 24 keyboard circuit diagram; 25 keyboard control PCB with the key matrix (PDF 25-26)
* 26-27 CPU PCB; 28-29 CPU PCB Mk II (PDF 27-30)
* 30 PCW8256 printer mechanical parts list; 31 printer exploded drawing; 32 printer PC board (PDF 31-33)
* 33 monitor/keyboard electrical parts list; 34 electrical parts list (PDF 34-35)
* Unnumbered: three chassis schematic sheets (PDF 36-38), three printer circuit diagram sheets (PDF 39-41) and a repeat of the notes to service engineers (PDF 42)

== What it settles ==
=== Specification (p. 2) ===
The PCW8256 has a Z80A with 256K of RAM, about 112K of which is used as a RAM disc; a green monitor showing 90 columns by 32 lines; one 3-inch "flip over" drive giving 180K per side, with room for a second; an 82-key keyboard with its own microprocessor; and an integral printer giving about 20&nbsp;cps letter quality or 90&nbsp;cps draft (elite pitch), with tractor feed and single-sheet loading. Separate custom microprocessors run the printer and the keyboard. The CPS 8256 serial and parallel interface is an option. The PCW8512 has 512K of RAM, giving a 368K RAM disc, and a second drive (1&nbsp;MB unformatted) as standard. The software is Amstrad's word processing program, CP/M Plus with GSX, Locomotive Software's Mallard BASIC and Dr LOGO.

=== Service notes and safety test (pp. 2-3) ===
The safety test is a 4&nbsp;kV flash test between the joined mains live and neutral and all accessible exterior metal, and an insulation test requiring at least 4&nbsp;M&Omega;. Amstrad's notes say that full diagnostics are not in the manual and that in-depth fault-finding needs the R.P.3 diagnostic tool. Drive mechanisms and their boards, including a second drive, are not to be serviced; exchange units come from Amstrad. Printer parts are listed, but complete printer mechanisms are available on exchange, as are complete circuit boards. The drive alignment pages (12-14) are for information only; during the warranty period the mechanism is returned with its board.

=== Monitor and power supply (p. 17) ===
The monitor board carries the 12&nbsp;V and 5&nbsp;V supplies. The alignment chart sets 12&nbsp;V with VR5002 and 5&nbsp;V with VR5001, each to within 2%, measured at CD102 pins 2 and 3 with CD101 disconnected; then vertical size and linearity (15&nbsp;mm top and bottom borders, 16&nbsp;mm left and right, with the RP3 or a pattern disc), horizontal hold at 15.625&nbsp;kHz, and cut-off. The equipment list is a digital voltmeter, oscilloscope, frequency counter and test pattern generator.

=== Parts lists (pp. 22-23, 33-34) ===
The cabinet parts list gives separate PCW8256 and PCW8512 part numbers. It lists the CRT as a 340AXB31 (171020) and, for the PCW8512 only, a compact floppy disc drive EME-231 (171224). The electrical parts list gives the main chips: Z8400AP processor (IC102), Amstrad 40028 (IC101), µPD765AC-2 floppy controller (IC203), Amstrad 40026 printer controller (IC701) and Amstrad 40027 keyboard controller (IC801), with eight TMM41257P-15 DRAMs for the 256K machine. The mains fuse F5001 is 2&nbsp;A time-lag, 250&nbsp;V (1400253). In the printer mechanical parts list, starred parts are for the PCW8512 only.

=== Memory options (chassis schematic, PDF p. 36) ===
The first chassis sheet carries Amstrad's memory options table for the CPU board:

{| class="wikitable styled-table" style="width:70%; text-align:center;"
|+'''Memory options (chassis schematic, PDF p. 36)'''
! Memory (K) !! DRAM size (K) !! Link A !! Link B !! Link C !! Link D !! ICs fitted !! Quantity
|-
| 512 || 256 || off || on || off || on || IC104-119 || 16
|-
| 256 || 256 || on || off || off || on || IC104-111 || 8
|-
| 128 || 64 || off || on || on || off || IC104-119 || 16
|-
| 128 || 256 || on || off || on || off || IC104-107 || 4
|}

The other chassis sheets cover the CPU board logic, including the printer control section around the Amstrad 40026 (IC701). The printer circuit diagrams include the 24&nbsp;V power connections.

=== Another scan ===
A 34-page scan of the manual (Internet Archive item [https://archive.org/details/amstrad-pcw-8256-pcw-8512-service-manual amstrad-pcw-8256-pcw-8512-service-manual]) lacks the chassis and printer sheets but has one extra page: a typed Mastercare sheet signed P.S. Wright, Mastercare PC+, "Fitting 4 pin CPU PCB in PCW8256 / PCW8512". It explains how to fit a replacement CPU board with a 4-pin power header: the 5-way monitor power connector is cut into a 3-way and a 2-way part, the 3-way part fitted with the yellow wire nearest the piezo buzzer, and the 2-way part fitted by its black wire pin, leaving the brown wire unconnected. The sheet is not part of Amstrad's manual.

== What this manual does not contain ==
There is no fault-finding procedure for the computer itself; the flow charts cover the drives, and the notes refer the engineer to the R.P.3 diagnostic tool. There is no memory map or I/O port list; for those see [[Amstrad PCW Hardware Reference (John Elliott)]]. The PCW 9256, 9512 and 9512+ have separate manuals.

<pdf> File:Amstrad PCW 8000 Series Service Manual.pdf </pdf>

Download: [[:File:Amstrad PCW 8000 Series Service Manual.pdf|Amstrad PCW 8000 Series Service Manual.pdf]]

== Related pages ==
* [[Amstrad PCW 9256 Service Manual]]
* [[Amstrad PCW 9512+ Service Manual]]
* [[Amstrad PCW Hardware Reference (John Elliott)]]

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[[Category:Amstrad Service Manuals]]
[[Category:Service Manuals]]