A tally on the number of successful builds of the Harlequin

edited March 2015 in Hardware
A tally on the number of successful builds of the Harlequin.

Please post your successes below :-)
rune wrote: »
Would it be too late to add a poll to show the count?
Yes, but as long as people post one post with details of each successful build and don't post any other separate entries, the number of replies to the thread will give the number built ;-)

Post edited by 1024MAK on


    edited May 2014
    One Harlequin built, 100% alive.
  • edited May 2014
    Add another Harlequin - built with no issues :)



    The Spectrum Resuscitation Thread - bringing dead Spectrums back to life
    zx-diagnostics - Fixing ZX Spectrums in the 21st Century (wiki)
    Sinclair FAQ Wiki
  • edited May 2014
    And another, only problems were my own making. 100% working now.

    Would it be too late to add a poll to show the count?
  • ZupZup
    edited May 2014
    I built mine with one of the boards manufactured by flopping. It has composite video output, a "dual" EPROM with a switch to change between lower and upper 16k halves and was placed in a ZX Spectrum + case.

    The manufacturing process went fine, paying attention to the documented problems for that board (cut some traces and rewire them, and the power connector didn't fit well in place).

    After building I had problems with keyboard and cassette input, but after replacing U6 (from an LS to an HCT variant) it works fine.
    I was there, too
    An' you know what they said?
    Well, some of it was true!
  • edited May 2014
    One Harlequin built, tested and used frequently!

  • edited May 2014
    rune wrote: »

    Would it be too late to add a poll to show the count?

    Oops, sorry 1024mak, but What a great idea! Please, could a moderator delete this?
  • edited May 2014
    One Harlequin working fine here (and thanks to Ingo for identifying a faulty Z80 - odd that, as I was careful and took static precautions).

    I'll do the R48 mod this weekend - hopefully that'll cure the rolling screen problem I have on one of my TVs.

  • edited May 2014
    One build, no difficulties, working perfect right away. Tried one monitor, one LED TV
    Now attached to Opus Discovery for a while.
  • edited May 2014
    One built and working successfully

  • edited May 2014
    One built, 100% working, with R48 mod.

  • edited May 2014
    One built, 100% working (once I realised I had to add a jumper, doh!).

    Slowly adding pictures I took during the build here:
  • edited May 2014
    Mine's built and working :) @ at 16K.

    Awaiting a replacement RAM to bring me back up to 48K.

  • edited May 2014
    One built and working (needed an extra cap on U13).
  • edited May 2014
    one working (built by Ingo himself :-) )
  • edited May 2014
    Seeing this a new thread to count the number of working Harlequins, mine is also working as posted in the "Harlequin clone...PCB manufactured! thread".

    For the Harlequin owners who have not read the thread :

    After the assembly of my Harlequin, it did not start up. I traced the problem to the oscillator with U13. I used a NXP 74HC04N and it does not want to oscillate. I tried a ST and Goldstar 74HC04 and with both components the Harlequin boots correctly. The NXP 74HC04 test correctly on my IC tester, but does not want to work as an oscillator in the circuit at that specific frequency.
  • edited May 2014
    Mine is also working perfectly. Please do not forget to modify one pin connection of R48 as discribed in other Harlequin thread. The one pin of R48 next to the Cinch jack (initially connected to VCC) has to be desoldered and has to be connected to ground. This is necessary to prevent DC offset at sync line of SCART and to enable a DC path for the sync driver in case of using a CGA-VGA converter or any SCART using device with no DC path at sync line.

    Note also that there is no +/-12V and -5V at the associated pins of the edge connector of the Harlequin. This is the reason why the serial port of IF1 may not work properly or the Beta Disk interface which uses also the +12V line. An additional DC-DC converter can solve the problem.
    I will start a "mod thread" for the Harlequin next days with usefull tips for mods (not much I hope).

  • edited May 2014
    The Harlequin of Norbert, the organizer of the annual Spectrum meeting in Wittenberg/Germany (every year in August) works also perfectly after making it. I made this for him.

  • edited May 2014
    I am pleased to report that my first Harlequin is up and running!




    I still need to do the R48 mod, solder in the loudspeaker and some keyboard headers and run the tests, but a signal out means not much can be wrong! :) Yay!

    It's time to design the case! (And maybe figure out what is wrong with my Issue One as well....)

    General feedback:

    0. @Ingo: Thank you for organizing everything, communicating the whole way through, providing top-quality components and providing support during everyone's build.
    1. The build quality of the PCB is excellent - really top level stuff! :)
    2. I have to learn how to drag-solder: that first SMD was a pain.
    3. I was wondering whether there was a through-hole equivalent for the large inductor? Any technical reason why a SMD device was chosen? Just curious.
    4. Runs really cool and quiet; having been working on the Issue One with its toasty regulator and loud buzzing, I was quite surprised at how cool and quiet this thing is. Amazing.
    5. Are there plans for a revision "G"? ;)

    @Ingo: I get no picture from composite, which I guess is the fault of not having done the R48 mod?
  • edited May 2014
    One Harlequin working here! not tested loading from tape as yet but working fine with divide. just done the R48 mod tonight but need to sort the resistor network devices since I ordered incorrect parts (temp mod on back of pcb)


  • laklak
    edited May 2014
    With bad eyes and shaky hands, my board became self aware after replacing the CD4040s (4Mhz too slow ?) with 74HC4040s.
    It now lives inside an old Spectrum+ case.
    Lotharek DivIDE 2K14 works nicely with the Z80 CPU that comes free with my small packet order. Thanks Ingo!
    Just need to shorten those reset pins to close the case nicely.

    Self declared Last Spectrum Owner in Singapore.
  • edited May 2014
    Two Harlequins up and running.
  • edited May 2014
    Simon_Carr wrote: »
    Oops, sorry 1024mak, but What a great idea! Please, could a moderator delete this?
    Added a poll to the thread, if you want it altered in any way please let me know.
    I wanna tell you a story 'bout a woman I know...
  • edited May 2014
    one build and working.
  • edited May 2014
    Assembled and working perfectly.
  • edited June 2014
    It took me a while, but i've finally got my Harlequin assembled. R48 mod included. It started with the testrom, and after moving the J12 jumper the ( C ) 1982 Sinclair Research Ltd came up as expected. After hooking a keyboard up, i did the Print Peek 23732+256*Peek 23733 which reported 65535, excellent...
    The composite image looks great.
    As i final test, i hooked up my old danish floppy interface CS-DISK and it worked beautifully...

    Again thanks to Ingo for the gargantuan effort.
  • edited July 2014
    It took me a lot of time but finally my Harlequin is up and running without any issues. Well, that's not 100% true because I didn't realize that the D12 bridge is not properly drawn on the board and I put the + down instead of right pin 4. After make this change everything worked ok.


    I didn't make the R48 mod and in my case it works on my old TV, I have not tested yet on my flat TV. RGB and Composite video output are excellent...Now is time to do some tests :)

    Thank you very much to Ingo who provided me the kit.
  • edited September 2014
    This weekend I finally took the time to build my Harlequin.
    Works perfectly. RGB picture is perfect!
  • edited September 2014
    Mine is running fine as well.
    I did a modification regarding the same output level of RGB and composite video and I added a S-Video output which can be obtained easily just with two additional wires and two resistors for free (non connected outputs of AD724).

    It's described in detail here:
  • edited November 2014
    I've finally got around to building my Harlequin, unfortunately it has a couple of issues.

    1. The loudspeaker doesn't work, I must have damaged it when soldering it in as connecting an external speaker to MIC work OK.

    2. Screen corruption. It looks like accessing the upper RAM can cause corruption on the screen. The screen is corrupted straight after reset but if I type CLEAR 32767 followed by NEW there is no corruption at the Sinclair prompt. Running 48K software eventually results in a crash or reset but 16K software seems to work OK.


  • edited November 2014
    Hi JonS,

    this is a known issue. The RAMs are ok.
    Look if at the bottom side there is a SMD capacitor between pins 14 and 15 of U42. If yes remove it. Instead solder a capacitor of about 100 pF between pins 12 and 13 of U24.
    The reason for this issue is that the circuitry around U17 and U24 produces small spikes at the output of U24D (pin 11) that causes undesired RAM access.

    The addidtional capacitor reduces the spikes. I found that a capacitor of 100pF between pins 12 and 13 of U24 OR a caapcitor of 1nF between pins 14 and 15 of U42 (depending on the brand of the logic chips) solves the problem.

    Also substituting U24 by a 74LS08 may help in some cases but I prefer the capacitor.

    Greets Ingo.
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