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Possibly daft Harlequin composite question... :SHi; My Harlequin Rev. F works fine apart from one aspect: there's no composite out... :( I have checked continuity and the discrete components. I.…
Yep, no need to set PAL/NTSC jumpers as the appropriate options are already linked on the PCB.
Silly question - is the AD724 soldered in the right way round, and free of shorts between pins?
B -
Possibly daft Harlequin composite question... :SHi; My Harlequin Rev. F works fine apart from one aspect: there's no composite out... :( I have checked continuity and the discrete components. I.…
Hi, Balford - the AD724 is mounted with the notch facing J9 as per Ingo's photographs. I shall check for shorts again now, but didn't find any last time... :) -
Possibly daft Harlequin composite question... :SHi; My Harlequin Rev. F works fine apart from one aspect: there's no composite out... :( I have checked continuity and the discrete components. I.…
can you make photos of top and bottom PCB of the section around the AD724 and show it here?
Ingo. -
Possibly daft Harlequin composite question... :SHi; My Harlequin Rev. F works fine apart from one aspect: there's no composite out... :( I have checked continuity and the discrete components. I.…
... could send you a new AD724.
Removing the old one ... -
Possibly daft Harlequin composite question... :SHi; My Harlequin Rev. F works fine apart from one aspect: there's no composite out... :( I have checked continuity and the discrete components. I.…
... the socket pole and the AD724 as I don't have ... -
Possibly daft Harlequin composite question... :SHi; My Harlequin Rev. F works fine apart from one aspect: there's no composite out... :( I have checked continuity and the discrete components. I.…
... problems with some chips of AD724 to start-up oscillation. I ... the composite output of the AD724.
I would be ... -
Possibly daft Harlequin composite question... :SHi; My Harlequin Rev. F works fine apart from one aspect: there's no composite out... :( I have checked continuity and the discrete components. I.…
As I told before, I could send you a new AD724 (in an envelope) or you can send me the PCB for repairing it.
Greets Ingo. -
Possibly daft Harlequin composite question... :SHi; My Harlequin Rev. F works fine apart from one aspect: there's no composite out... :( I have checked continuity and the discrete components. I.…
... knacker the board desoldering the AD724.
I'll practice ... -
important Harlequin modWhile searching for a better solution for avoiding undesired spikes that corrupt the screen RAM at Harlequin I found a final solution. No additional …
... because inside the PAL coder AD724 the composite sync signal is ... -
Harlequin Rev. G - Composite video problem.What I'm about to describe I'm not experiencing it by myself, so the probable answer to any "have you tested this or that" question is no, I don't, b…
... same, a problem around the AD724 (RGB to CVBS) but do ... -
Harlequin Rev. G - Composite video problem.What I'm about to describe I'm not experiencing it by myself, so the probable answer to any "have you tested this or that" question is no, I don't, b…
... question that poped reading the AD724 datasheet.. If what has happened ... -
Harlequin Rev. G - Composite video problem.What I'm about to describe I'm not experiencing it by myself, so the probable answer to any "have you tested this or that" question is no, I don't, b…
... in the datasheet of the AD724. It was found by experiment ... the oscillator pin of the AD724 was touched after powering up ... for any brand of the AD724 but it was found not ... -
A tally on the number of successful builds of the Harlequin[SIZE=4][COLOR=Green][U][B]A tally on the number of successful builds of the Harlequin.[/B][/U][/COLOR][/SIZE] Please post your successes below :-) …
... [/b] SMD parts as the AD724 (video coder), the switching regulator ... -
A tally on the number of successful builds of the Harlequin[SIZE=4][COLOR=Green][U][B]A tally on the number of successful builds of the Harlequin.[/B][/U][/COLOR][/SIZE] Please post your successes below :-) …
Harlequin clone...PCB manufactured!Using Chris Smith's detailed schematics and project notes from the Harlequin... a Speccy fan in the United States by the name of Don (Superfo) has de…
... bad hence considering redoing the AD724. I should have practiced some ...Harlequin clone...PCB manufactured!Using Chris Smith's detailed schematics and project notes from the Harlequin... a Speccy fan in the United States by the name of Don (Superfo) has de…
... if pin 15 of the AD724 is isolated to +5V. The ... a detailed photo of the AD724 and around?
Greetings ...Harlequin clone...PCB manufactured!Using Chris Smith's detailed schematics and project notes from the Harlequin... a Speccy fan in the United States by the name of Don (Superfo) has de…
... if pin 15 of the AD724 is isolated to +5V. The ... a detailed photo of the AD724 and around?
Greetings ... too embarrassed) to show the AD724 up close. If it's ...128 +2 grey, no video but still beepsGot a grey 128 from ebay, im using a 48k spectrum powers supply, all voltages seem ok. I cant get compostie video using the normal mod or from the 8…
... i might try getting an ad724 chip which may be able ...RGB InterfaceSeen a few of these on eBay recently, are there any modern solutions to RGB on the 48K? Were all busy composite modding, but wouldn't RGB be far bet…
I think the harlequin spectrum could do rgb without the surface mounted ad724 video composite chip.
that would make it cheaper to build. Plus you could pull the z80 from your old speccy. So it would still have the same personality so to speak.So for my first trick...I'm sure people have already used the AD724 or AD725 on other 8 bit machines, and i know the Harlequin uses the 724, but not seen anyone trying to us…
... an independant xtal, but the AD724 is virtually identical (just doesnt ...So for my first trick...I'm sure people have already used the AD724 or AD725 on other 8 bit machines, and i know the Harlequin uses the 724, but not seen anyone trying to us…
... a working TEA2000 by a AD724/5. Both chips have the ...So for my first trick...I'm sure people have already used the AD724 or AD725 on other 8 bit machines, and i know the Harlequin uses the 724, but not seen anyone trying to us…
... a filter. In addition the AD724/725 internally implement a delay ...Small batch of ZX-Unos outside SpainI am a member of the ZX-Uno team. We have launched a sucessfully crowdfunding campaign of 250 ZX-Uno, but they are all sold (mostly in Spain). I apol…
... view of hardware. Because the AD724 has both NTSC and PAL ...Newly Acquired +3 in the USAI just acquired (rather accidentally, was looking for an empty Spectrum + case!) a pretty nice Spectrum +3, and a US-spec PSU. As far as I can tell …
... the 40056 ULA does. The AD724 would be better fit for ...ZX Speccy +2A - B&W & snowy RF output + other issuesHi All, I am new to this forum and I am back to the Spectrum world after 25 years. Recently I've bought a second hand +2A (+2B board - Z70833 Issu…
... S-Video output using the AD724 or something like it.Spectrum +2 grey RF removalHi everyone. If I were to remove RF output from a +2, just intending to keep Composite video out from TEA2000, then all the components that make t…
Removing those parts should be fine. If you want a really good svideo output, i'd replace the TEA2000 completely with an AD724 or AD725 based circuit.Spectrum +2 grey RF removalHi everyone. If I were to remove RF output from a +2, just intending to keep Composite video out from TEA2000, then all the components that make t…
... the TEA2000 completely with an AD724 or AD725 based circuit. [/quote ... am not familiar with the AD724/725 IC's. Maybe on ...Spectrum +2 grey RF removalHi everyone. If I were to remove RF output from a +2, just intending to keep Composite video out from TEA2000, then all the components that make t…
... am not familiar with the AD724/725 IC's. Maybe on ... ]
No problem. The AD724 and AD725 are quite easy ...
