The ZX Spectrum Reverse Engineering and Clone Desgin Blog


A site dedicated to the reverse engineering of the ZX Spectrum and related projects.

Harlequin Schematics

Please credit the original author, Chris Smith, and provide links to this Blog in any works or projects that derive from the contents of this Blog. This not only ensures that your readers have access to the full development history of a project, but also politely attributes credit where due.

The schematics for this project will evolve over time, as will this blog. It will be important to make available all versions of the schematics as they represent points in time and key phases of the Harlequin design.

Schematics and versions are listed and downloadable below. The schematics with the same version numbers are at the same stage of development, and should be viewed together. For a complete set, view the highest version numbers of each file.

Schematic Version Date File Comment
Horizontal Control1.1Mar 20, 2007horizvideo-1.1.pdf 
 1.2Apr 05, 2007horizvideo-1.2.pdf 
 1.4Apr 24, 2007horizvideo-1.4.pdf 
 1.5May 04, 2007horizvideo-1.5.pdf 
 1.6May 20, 2007horizvideo-1.6.pdf 
 1.7May 28, 2007horizvideo-1.7.pdf 
 1.10Jun 30, 2007horizvideo-1.10.pdf 
 1.13Aug 10, 2007horizvideo-1.13.pdf 
 1.17Nov 26, 2007horizvideo-1.17.pdf 
 1.19Mar 14, 2008horizvideo-1.19.pdfClk7 synced with HC
Vertical Control1.1Mar 29, 2007vertvideo-1.1.pdf 
 1.2Mar 30, 2007vertvideo-1.2.pdf 
 1.3Apr 05, 2007vertvideo-1.3.pdf 
 1.4Apr 24, 2007vertvideo-1.4.pdf 
 1.5May 05, 2007vertvideo-1.5.pdf 
 1.6May 20, 2007vertvideo-1.6.pdf 
 1.17Nov 26, 2007vertvideo-1.17.pdfFull VSync Implementation
 1.17sNov 26, 2007vertvideoSimple-1.17.pdfCutdown VSync implementation
Video Ouput1.4Apr 29, 2007videoout-1.4.pdf 
 1.5May 04, 2007videoout-1.5.pdf 
 1.6May 20, 2007videoout-1.6.pdf 
 1.7May 28, 2007videoout-1.7.pdf 
 1.16Sep 04, 2007videoout-1.16.pdf 
 1.17Nov 26, 2007videoout-1.17.pdf 
Video Memory1.4Apr 30, 2007videomem-1.4.pdf 
 1.6May 20, 2007videomem-1.6.pdf 
 1.7May 28, 2007videomem-1.7.pdf 
 1.18Mar 10, 2008videomem-1.18.pdfDynamic RAM support
Dynamic Video Ram1.18Mar 10, 2008dynamicRam-1.18.pdf 
CPU Control1.6May 20, 2007cpucontrol-1.6.pdf 
 1.7May 28, 2007cpucontrol-1.7.pdf 
 1.8Jun 20, 2007cpucontrol-1.8.pdf 
 1.11Jul 15, 2007cpucontrol-1.11.pdf 
 1.16Oct 07, 2007cpucontrol-1.16.pdf 
Interfaces1.8Jun 20, 2007interfaces-1.8.pdf 
 1.9Jun 24, 2007interfaces-1.9.pdf 
 1.15Aug 27, 2007interfaces-1.15.pdf 
Clock1.1May 04, 2007clock-1.1.pdf 
 1.10Jun 30, 2007clock-1.10.pdf 
 1.11Jul 15, 2007clock-1.11.pdf 
 1.12Jul 28, 2007clock-1.12.pdf 
 1.16Oct 07, 2007clock-1.16.pdf 
 1.19Mar 14, 2008clock-1.19.pdfMaster Clk14
Wait Generator1.11Jul 15, 2007waitGen-1.11.pdf 
 1.12Jul 28, 2007waitGen-1.12.pdf 
 1.13Aug 10, 2007waitGen-1.13.pdf 
 1.14Aug 20, 2007waitGen-1.14.pdf 
 1.15Sep 16, 2007waitGen-1.15.pdf 
 1.16Oct 07, 2007waitGen-1.16.pdf 
 1.17Nov 26, 2007waitGen-1.17.pdf