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Amstrad PCW 8512

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Amstrad PCW 8512
PCW8512 monitor unit with its two 3-inch drives, and keyboard
Specifications
ManufacturerAmstrad Consumer Electronics plc
TypeWord processor and CP/M personal computer
CPUZilog Z80A (Z8400AP) at 4 MHz
Memory512 KB (sixteen 256K × 1 DRAMs), 368 KB of it used as RAM disc
StorageTwo 3-inch drives: drive A single-sided, 180 KB per side; drive B double-sided, 720 KB formatted
DisplayBuilt-in green monochrome monitor, 90 × 32 characters, 720 × 256 pixels
SoundPiezo buzzer
Ports / interfacePrinter data and power, keyboard (4-pin DIN), expansion edge connector
Power220–240 V 50 Hz mains; supply in the monitor unit
OS / FirmwareLocoScript, CP/M Plus
PredecessorAmstrad PCW 8256
SuccessorAmstrad PCW 9512
Model no.PCW8512

The Amstrad PCW 8512 is the larger version of the Amstrad PCW 8256, launched a few months after it. Amstrad's specification describes it as the PCW8256 with 512K of RAM, giving a 368K RAM disc, and with a second disc drive fitted as standard, 1 MB unformatted.[1][2] Everything else, from the monitor and power supply to the printer and keyboard, is shared with the 8256, and the guides for that machine apply. Schneider sold the 8000-series designs in Germany as the Joyce and Joyce Plus.[2]

Differences from the PCW 8256

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PCW8512 compared with the PCW8256 (service manual)
Item PCW8256 PCW8512
RAM 256K, eight DRAMs at IC104–IC111 512K, sixteen DRAMs at IC104–IC119
RAM disc About 112K 368K
Drives One single-sided drive; a second can be added Single-sided drive A plus double-sided drive B (EME-231, part 171224)
Memory links A on, B off, C off, D on A off, B on, C off, D on

[1]

The list of PCW8512 parts that differ from the PCW8256 adds the DRAMs IC112–IC119 (TMM41257P-15), resistors R201–R205 and R726, small capacitors C206–C210 in the 200 series that also holds the floppy controller (IC203), and a 0.01 µF 250 V AC capacitor at C4034. It gives revised board numbers, including CPU board 13MC0029C1. It lists no electrolytic capacitors.[1] The cabinet parts list gives separate PCW8512 part numbers for the front cabinet (171215), stand, control knob, power button, back, keyboard top and bottom, keyboard cord and buzzer; the printer parts list stars the PCW8512 dust cover, cabinet top and bottom.[1]

Drive B

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The user guide calls the top drive A and the bottom drive B. Drive B adds 1 MB of storage, 720K formatted. It writes double-density discs (CF-2DD), uses twice as many tracks per side as drive A and reads both sides without the disc being turned over, so side 1 must always face the screen.[3]

Which drive can use which disc (user guide Part III)
Disc Read in drive A Read in drive B Write in drive A Write in drive B
CF-2, created in drive A Yes Yes Yes No
CF-2DD, created in drive B No Yes No Yes

[3]

Using a disc in the wrong drive gives "Disc unsuitable" or a CP/M error such as "Disc I/O" or "File non-recoverable".[3] Amstrad sold CF2DD discs for drive B, but users found that ordinary CF2 discs work in it too, which matters now that CF2DD discs are hard to find.[4] An 8256 can be brought up to 8512 standard by fitting a CF2DD drive as drive B and the eight extra DRAMs, and changing the memory setting.[4]

Servicing

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The 8256/8512 service manual covers both machines. Its drive flow charts and alignment checks give the figures for the second drive, FD2, in brackets, and the seek error chart is for FD2 only.[1] The Amstrad PCW 8512 Maintenance Guide and Amstrad PCW 8512 Troubleshooting Guide cover drive B and the 512K memory; the rest of the machine is in the Amstrad PCW 8256 Maintenance Guide and Amstrad PCW 8256 Troubleshooting Guide. The electrolytic capacitors are the same as the 8256's; see the Amstrad PCW 8256 Capacitor Replacement Guide.

The keyboards of the two machines are marked 256K and 512K but are interchangeable.[4]

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References

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  1. ↑ 1.0 1.1 1.2 1.3 1.4 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. Specification p. 2; drive flow charts and alignment checks pp. 5–14 (bracketed figures for FD2); cabinet parts list with separate 8256 and 8512 part numbers p. 23 (PDF p. 24); printer mechanical parts list, starred parts for the PCW8512 only, p. 30 (PDF p. 31); list of PCW8512 parts different to the PCW8256 p. 34 (PDF p. 35); memory options table (PDF p. 36).
  2. ↑ 2.0 2.1 Wikipedia, "Amstrad PCW" (revision 1361595210). Retrieved 2026-10-02. The PCW 8512 launched a few months after the PCW 8256; the single-sided upper drive and double-sided, double-density lower drive; Schneider's Joyce and Joyce Plus.
  3. ↑ 3.0 3.1 3.2 Amstrad, The PCW8256 and PCW8512 User Guide and Guide to Locomotive Software's LocoScript (AMSOFT, 1985). Hosted as File:Amstrad PCW8256 PCW8512 User Guide (1985).pdf, described at Amstrad PCW 8256 / PCW 8512 User Guide. Part III, Two-Drive Operation, pp. 1–8: drive A and drive B, CF-2 and CF-2DD discs, which drive can read and write which disc, error messages, formatting drive B discs with DISCKIT.
  4. ↑ 4.0 4.1 4.2 Richard Lloyd, PCW article ("Fifty two years and counting"), Amstrad CPC User Club Magazine (ACUC) issue 1, June 2022. Scan at archive.org. Retrieved 2026-10-02. The 8512's drive A the same as the 8256's; drive B uses both sides and holds 720K; CF2 discs used in drive B; the 8256 and 8512 keyboards marked 256K and 512K but interchangeable; converting an 8256 to an 8512.