ZX Spectrum Harlequin

After spending a good few hours reading up on retro computers and wanting to relive my childhood I’ve decided to give the ZX Spectrum Harlequin a go.

Yes, I know its probably cheaper to buy a complete assembled board or even a ZX Spectrum from eBay, but where is the fun in that!

There are many blogs and sites out there with a wealth on info so this should be a fun journey.

From ByteDelight:

A couple of years ago, Chris Smith reverse engineered the ZX Spectrum ULA (you can obtain the ZX Spectrum ULA Book to read about that).
Chris also developed the Harlequin: a ZX Spectrum 48K clone based on parts that replace the ULA, so no ULA is needed.
ZX Spectrum fans continued on this development which resulted in the design that is now known as the ‘Harlequin Superfo’. The current rev G is the most stable one.
You can now assemble a complete and 100% compatible ZX Spectrum 48K clone yourself!


I’ve decided to try and do this as cheaply as possibly and source the components from various locations.

First order of business. Order stuff!

  • Ordered Harlequin PCB from eBay for £15

  • Ordered ZX Spectrum case and keyboard from eBay for £10
  • For the parts list I started of with a bill of materials that Sergey Kiselev posted on his blog.

I already had some of these components  so managed to trim the list down. The remainder of the items I ordered from Mouser and eBay.  (Components mostly from China shipping time will be long but prepared to wait)

Link to my  Spectrum Harlequin BOM with prices.

I’ve also ordered a AT28C256 instead of the EPROM as this lets you reprogram the chip. The AT27C256 is a OTP.

Next, while I wait for parts I need to look it an Arduino based EEPROM programmer. Simple EEPROM Programmer from this site looks interesting.



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