Make this my favourite ZX NUCLEON 512KB - clone ZX Spectrum 128KB and Pentagon 128/512 into ZX Spectrum case - DIY Kit

Retro Computers >> Sinclair >> Sinclair ZX Spectrum >> Hardware >> General / Add-Ons
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Seller location:
Karlovy Vary, Drahovice, Czech Republic
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Latest buyer:
d***a (0)
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Buyer Value Date and hour Quantity bought
d***a (0) $89.40 USD 04/01/2020 18:06:54 1
s***a (0) $82.00 USD 01/01/2020 17:25:10 1
Z***a (0) $99.50 USD 23/11/2019 05:40:58 1

Item Number : 39841

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Fixed price: $99.00 USD
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ZX NUCLEON 512KB - Pentagon (ZX Spectrum) clone

New version with improved picture quality and other improvements!

Self home-made DIY Kit (PCB and all components, not soldered)


Tested with DivIDE 2k14 (Lotharek version), DivMMC Lite (Bytedelight version)

ATTENTION! Please excuse the delay in shipping due to illness.
Orders will be processed at the end of January 2020.
Thank you and I wish you all the best for 2020!
The current PCB color is RED or GREEN!


CAUTION Important! If you would like to build a kit yourself, please note that you agree to the following purchase
notice: It is a very complicated design, the components are very densely mounted on the PCB, to build it requires
high skills in electronics and high knowledge and instrumentation, if by chance the board does not work on the first
switch-on! Unfortunately, I myself have no time to provide help-line either personally or remotely! Therefore,
please purchase the kit only if you know that you are able to find a possible problem yourself and solder extremely
complex constructions. Thank you.


ZX NUCLEON 512KB is a new clone of ZX Spectrum computer, respectively Pentagon 128KB/512KB computer. The motherboard is the same size as the ZX Spectrum 48KB computer board and will fit into his case.

Electrical wiring is largely based on Pentagon 128KB/512KB computer and keeps timing important parts of the computer! ZX NUCLEON 512KB uses modern SRAM memory instead of historical dynamic RAM. There are also some minor modifications, bug fixes, and a better video part including RGB video output. The computer also contains a program sound generator AY-3-8910A.

Important improvements opposite all competing projects: All I / O signals between the CPU and the bus are amplified by drivers!
This means greater capabilities and reliability with connected external peripherals and CPU protection against damage.


Why buy ZX NUCLEON 512KB and not another, competitive project?

The vast majority of the best quality software from the 199x-20xx period comes from the countries of the ex-USSR. This software largely uses Pentagon timing and does not work on ZX Spectrum and its derivatives. That's why ZX NUCLEON is the best choice for the future.



- CPU tact frequency 3,500MHz (classic Pentagon mode), Pentagon video timing

- 512KB fast RAM, 32KB classic 128's ROM

- RAM paging compatible with Pentagon 512KB or 128KB or Spectrum 128KB (bits 0,1,2,6,7 on port 32765d)

- Function blocking 512KB with switch (128KB forced mode)

- Build on quality LS/ALS integrated circuits

- Two video output formats: S-VHS (PAL) and analog RGB (NTSC not supported)

- Mixed audio stereo output: AY-3-8910 (switchable ABC or ACB mode) + BEEP + Tape in/out

- Tape in amplifier

- Original ZX Spectrum rubber keyboard supporting

- All I/O signals between the CPU and the bus are amplified by drivers

- Classic power source from ZX Spectrum (9VDC with central negative pole)


Link for documents download:

Link for my web about ZX Spectrum projects:


Thank you for your support and have a nice day :-) CSS Electronics

Overview photos, real PCB can be equipped with compatible components of other brands:

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Item Location:
Karlovy Vary, Drahovice, Czech Republic
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Buyer pays shipping expenses
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  • To Czech Republic :
  • First Class Post : $8.00 USD For initial item, $1.00 USD Per additional item
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  • Airmail Post : $16.00 USD For initial item, $1.00 USD Per additional item
  • To Europe (Non EU) :
  • Airmail Post : $16.00 USD For initial item, $1.00 USD Per additional item
  • To Americas :
  • Airmail Post : $20.00 USD For initial item, $3.00 USD Per additional item
  • To Rest of World :
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