ZX Spectrum +2

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Infobox: ZX Spectrum +2
Manufacturer Amstrad
Mfg. volume
CPU Z80A @ 3.5469MHz
ROM 64KB
RAM 128KB
as pages 8×16KB
Gfx Res 256×192
Gfx Colours 15 (2 per 8×8 cell)
  • This article is about the early "Grey +2". For the later "Black +2" (+2A and +2B) see ZX Spectrum +3/2A/2B


Hardware Revisions

This is an attempt to pin down the various hardware revisions of the +2 Grey. There seem to be three main revisions of the PCB, within these there appear to be separate date coded batches

Z70500

  • Comments: Presumably the earliest versions of this board were created prior to the Sinclair takeover
  • Place of manufacture: These boards appear to have been manufactured in Taiwan, this is embossed on the underside of the case.
  • Date of manufacture (batch): The date code for the PCB batch is recorded on the top right corner on the rear of the PCB in the traces, in this case 32nd Week of 1986: [1]
  • Distinguishing features: Fitted with radial capacitors, 2 bodge resistors and a capacitor on the rear of the PCB.
  • Problems:
    • Requires TR4 mod for misplaced transistor.
    • Not only should TR4 be rotated but also TR7. If TR7 is mounted in the false direction then the transistor, which normally acts as an emitter follower, only acts as a diode. The base-collector-diode together with R65 realizes the OR function. But in this case A0 is loaded by 470 Ohm which would be avoided if TR7 would be mounted correct. (Ingo)
  • Variants:

Standard 8632 (1986 Week 32)/ 8642 (1986 week 42): Schematic [2] Mid (1987? Week 21): ROM has text rotated on it, date code 8721 [3](image nvg)

Serial numbers:

  • A six digit number proceeded by a U
  • U-102726: 8632

Photos

Z70700

  • Comments: Manufactured in the UK once stocks of the toast rack PCB were used up?
  • Place of manufacture: These boards appear to have been manufactured in UK, this is embossed on the underside of the case.
  • Date of manufacture (batch): The date code for the PCB batch is recorded on the bottom left corner on the PCB in the silkscreen
  • Distinguishing features: Fitted with axial capacitors (excess stock left over from the toast rack?). Lots of small coloured stickers on the modulator and elsewhere in the case.

Variants:

  • 3886 (1986 Week 38): Bodge resistor on bottom left hand corner of the board (R86?)
  • 8640 (1986 Week 40): Colour of capacitors change [5] (Ben Verstee)
  • 8645 (1986 Week 45): Colour of capacitors change, different diodes, changes to resistors in bottom left corner of the board [6] (Tom Dalby)

Serial numbers:

  • A six digit number followed by a T, e.g.:

[7]:

  • 005711T: (3886)
  • [8]: (8645?)
  • [9]:

Photos

0500 (Z70500 is on the rear side)

  • Comments: A later varient of the Z70500 (see also) possibly originally for the French market, but UK versions also exist.
  • Place of manufacture: Taiwan (embossed on bottom of case and PSU sticker).
  • Date of manufacture (batch): ? 8641A listed on the front bottom silkscreen of later revisions
  • Distinguishing features: Encased inductor, capacitor colour change, rear-side bodges of Z70500 corrected and paced on the front. Fixed HAL chip.

Variants:

  • UK (1986 Week 37): [12] (Tom Dalby)
  • UK 8641A (1986 week 41): Amstrad 4056 instead of PCF1306P [13] (nightfall crew)
  • France (1986): The modulator and associated components are not fitted, French ROM (40068)[14] (moo5)

Serial numbers: A six digit number proceeded by a U


Photos