ZX Spectrum +2
|CPU||Z80A @ 3.5469MHz|
|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
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
- 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.
- Distinguishing features: Fitted with radial capacitors, 2 bodge resistors and a capacitor on the rear of the PCB.
- 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)
- A six digit number proceeded by a U
- U-102726: 8632
- 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.
- 3886 (1986 Week 38): Bodge resistor on bottom left hand corner of the board (R86?)
- 8640 (1986 Week 40): Colour of capacitors change  (Ben Verstee)
- 8645 (1986 Week 45): Colour of capacitors change, different diodes, changes to resistors in bottom left corner of the board  (Tom Dalby)
- A six digit number followed by a T, e.g.:
0500 (Z70500 is on the rear side)
- Comments: A later variant 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.
- UK (1986 Week 37):  (Tom Dalby)
- UK 8641A (1986 week 41): Amstrad 4056 instead of PCF1306P  (nightfall crew)
- France (1986): The modulator and associated components are not fitted, French ROM (40068) (moo5)
Serial numbers: A six digit number proceeded by a U