ZX Spectrum +2

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.

• 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 [1] Mid (1987? Week 21): ROM has text rotated on it, date code 8721 [2](image nvg)

Serial numbers:

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

Photos

• [3]

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 [4] (Ben Verstee)
• 8645 (1986 Week 45): Colour of capacitors change, different diodes, changes to resistors in bottom left corner of the board [5] (Tom Dalby)

Serial numbers:

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

[6]:

• 005711T: (3886)
• [7]: (8645?)
• [8]:

Photos

• [9]
• [10]

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.

Variants:

• UK (1986 Week 37): [11] (Tom Dalby)
• UK 8641A (1986 week 41): Amstrad 4056 instead of PCF1306P [12] (nightfall crew)
• France (1986): The modulator and associated components are not fitted, French ROM (40068)[13] (moo5)

Serial numbers: A six digit number proceeded by a U

• U-091998: 8639 [14]
• U205749: 8641A [15]

Photos

• Nightfall crew
• MatGubbins