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Sinclair ZX Spectrum +2 128K

Introduction

The ZX Spectrum +2 was Amstrad's first Spectrum, coming shortly after their purchase of the Spectrum range and "Sinclair" brand in 1986.

Launched in early 1987, the machine featured an all-new grey case featuring a proper spring-loaded keyboard (at last), dual joystick ports, and a built-in cassette recorder dubbed the "Datacorder".  The Amstrad influence was obvious with its design similar to the CPC464, but was in most respects it was identical to the Sinclair ZX Spectrum 128.

The main menu screen lacked the Spectrum 128's "Tape Test" option, and the ROM was altered to account for a new 1986 Amstrad copyright message. These changes resulted in minor incompatibility problems with software that accessed ROM routines at certain addresses (this had been sorted to a certain degree by the time the Issue 2 boards were fitted in machines.

The new keyboard did not include the BASIC keyword markings that were found on earlier Spectrums, except for the keywords LOAD, CODE and RUN which were useful for loading software. This was not a major issue however, as the +2 boasted a menu system, almost identical to the ZX Spectrum 128, where one could switch between 48k BASIC programming with the keywords, and 128K BASIC programming in which all words (keywords and otherwise) must be typed out in full (although the keywords are still stored internally as one character each). Despite these changes, the layout remained identical to that of the 128.

Built in Taiwan, it became the first "Sinclair" product to be built outside the UK.  However, with Amstrads greater emphasis on quality control, it was far more reliable than any of the earlier generation Spectrums.
Production costs were lower and the retail price dropped to £149 soon after launch.

Technical Details

  • CPU: Z80A
  • Speed: 3.5MHz
  • ROM: 32KB (16K for 128K mode, 16K for 48K mode)
  • RAM: 128KB (8 x 16K banks)
  • Full-stroke 58 key Keyboard (same layout as Spectrum+)
  • Colour Graphics
  • Sound - 3 Channels, 7 Octaves
  • RGB, Keypad, RS232/Midi
  • Local price at launch: £200

Problems and Issues

My own experiences of problems with the Spectrum +2 mostly tend to centre around tape deck issues with early models with Issue one main boards.  Loading was very much a hit and miss affair with some +2's and no amount of tweaking the azimuth really helped.

Machines with Issue 2 boards do seem to be much better and I have swapped over cassette mechanisms from otherwise dead Issue 2's to Issue 1's with a lot of success.  This doesn't seem to make sense on the surface of it as the new mechanism is now in an Issue 1 board and so should be poor!  There was obviously some "invisible" upgrade made to the cassette decks (and their controllers) as well as the upgrade to the Issue 2 motherboard.

Over time without use, the main drive belt develops a pronounced and very visible (when you turn the pulley) kink where it has been parked stationary over the drive motor pully wheel, and this causes poor loading performance.  Replacing the belt is a simple task and I always have them available.  Instructions are available in my repairs section, including advice on how to check the azimuth (head alignment).

The small belt rarely gives problems, even now, and doesn't seem to perish.  Let me know if you need a replacement though.

Another common problem is the main drive wheel catching on a small spring loaded pad positioned just below it.  This causes the speed to fluctuate and again adversely affect loading performance.  Again, more details on how to put this right in the repairs section.

 

 

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