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1st interface in 30 yearsHi all, The last time I built a ZX Spectrum interface was 30 years ago, so today I gave it a whirl with an external rom. Switchable in/out of course…
... 's before it in the circuit.
[/QUOTE]
What ... LED that runs from the power rail would show you whether ... -
Next step for fixing my speccy?Hi guys, I've picked up my faulty Spectrum aiming to fix it. So I followed the excellent JouledperCoulomb videos on Youtube for the basics and I am …
... - this means the voltage converter circuit based around TR4 is fine ... it starts when you apply power. If you don't get ... splash giving a partial short circuit.
If it fails ... -
Next step for fixing my speccy?Hi guys, I've picked up my faulty Spectrum aiming to fix it. So I followed the excellent JouledperCoulomb videos on Youtube for the basics and I am …
... - this means the voltage converter circuit based around TR4 is fine ... it starts when you apply power. If you don't get ... splash giving a partial short circuit.
If it fails ... -
Next step for fixing my speccy?Hi guys, I've picked up my faulty Spectrum aiming to fix it. So I followed the excellent JouledperCoulomb videos on Youtube for the basics and I am …
... for the on board switching power supply for some board issues ... reliable in determining the actual circuit used.
So test ... -
Spectrum 48k ProblemsHi all Got my 48k today but it's playing up abit... First time i turn it on it was like this: [IMG]http://s26.postimg.org/hlg9d3f3d/IMG_20140830_…
... that the internal switched mode power supply inside the Spectrum is ... destruct.
So only power it up in this condition ... is part of the internal power supply circuit I talked about earlier ... -
Speccy Jam - New ZX Spectrum game development jam![IMG]http://1.bp.blogspot.com/-DYW9mHiExs4/U-fbD5oRuzI/AAAAAAAAOUg/dD0OM5DTyyM/s1600/Chuckie_Egg_2200738b.jpg[/IMG] [QUOTE]Dave from RetroYak has ju…
power ups would be so cool!< ... a great part of the circuit to plan where to overtake ... (separately or on the same circuit), also there could be some ... -
'Interesting' Issue 2 modSo I've been lurking on this forum for a while and I've got to the point where I want to see if I can repair a speccy.. so I bought me a 'broken' one…
... the on board switched mode power supply circuit has been upgraded, part ... -
48k - Why Won't it Buzzzz?Hi WOS ;) I bought a load of Spectrum games off eBay and thrown in for good measure was a 48k 1984 Issue 6a circuit board that I was told was for sp…
... the problem lies with the power convertor circuit but I'm now ... and then, replace TR4 and power the board. -
Faulty 48+ Help NeededHi, This is what I get when I plug in the spectrum, this is tuned in. Vid shows a reset. Any ideas, or pointers on the first thing to check. Keyboa…
... & TR5 test OK in circuit, power it on and measure the ... three power supply voltages at the lower ... -
Early ZX80/81 RAM Pack???Hey all I got given this RAM pack... It doesn't work (i know why now) but compared to my RAM pack this one is really strange... Is this a ZX80 RAM p…
... of the inverter circuit (the on-board switch mode power supply) is ... substantially different to the circuit used on ... the resistors. But in this circuit, the resistors are normally reliable ... -
'Interesting' Issue 2 modSo I've been lurking on this forum for a while and I've got to the point where I want to see if I can repair a speccy.. so I bought me a 'broken' one…
Honestly, I'm not sure I'd bother with rebuilding the original circuit unless there's no other option.
I'd be more inclined to replace the socket on the back with a more common molex and substitute in a Micro ATX power supply. -
Speccy Jam - New ZX Spectrum game development jam![IMG]http://1.bp.blogspot.com/-DYW9mHiExs4/U-fbD5oRuzI/AAAAAAAAOUg/dD0OM5DTyyM/s1600/Chuckie_Egg_2200738b.jpg[/IMG] [QUOTE]Dave from RetroYak has ju…
... could even be a bumper power-up for that purpose.
- minimap showing the circuit and the last car on ... could be one without ammo power-ups and just turbos, the ... -
48k Spectrum "Jail Bars" Removal?Hi all Just curious I think I saw a post here about the bars that go down the screen on some 48k's I think he referred to them as "jail bars". Any…
... the TR4/TR5/coil switching circuit
[*]Various frequencies (up to ... . There is no harm in replacing C1 to C4 with 1uF ... the TR4/TR5/coil switching circuit would also help. So on ... -
48k Spectrum "Jail Bars" Removal?Hi all Just curious I think I saw a post here about the bars that go down the screen on some 48k's I think he referred to them as "jail bars". Any…
... massive improvements in clarity after replacing C44/C45.
I ... 've done these and the power supply ones, you might as ... -
Hot plugable edge connector?Could the spectrum's edge connector have been made hot plugable without adding much to the manifacturing costs? I was thinking along the lines of a…
... /> The usual problem is that power supply rails are shorted to ... voltage converter circuit (and so destroys the lower RAM) or power is ... , an upper RAM IC when power is applied to its data ... -
Hot plugable edge connector?Could the spectrum's edge connector have been made hot plugable without adding much to the manifacturing costs? I was thinking along the lines of a…
... block the spectrum power plug completely and provide power to the spectrum ... properly seated before it allows power to be applied to the ... to one another) then the circuit is not too complex. But ... -
'Interesting' Issue 2 modSo I've been lurking on this forum for a while and I've got to the point where I want to see if I can repair a speccy.. so I bought me a 'broken' one…
... the internal inverter / switch mode power supply circuit (TR4, TR5 and the ... carry resistance tests with the power unplugged, otherwise you will get ... -
New video about S-video modification on Issue two 48K Spectrum.I just finished an s-video modification on an Issue two 48K Spectrum so I made a video about it. Most of the technical details are in the video; if y…
... , inductance and capacitance of a circuit. As the frequency of a ... what you may think, maximum power transfer occurs when the effective ... are not pumping lots of power around, so what this means ... ]
To reduce signal and power loss, the cable used should ... -
New video about S-video modification on Issue two 48K Spectrum.I just finished an s-video modification on an Issue two 48K Spectrum so I made a video about it. Most of the technical details are in the video; if y…
... , inductance and capacitance of a circuit. As the frequency of a ... what you may think, maximum power transfer occurs when the effective ... are not pumping lots of power around, so what this means ... ]
To reduce signal and power loss, the cable used should ... -
'Interesting' Issue 2 modSo I've been lurking on this forum for a while and I've got to the point where I want to see if I can repair a speccy.. so I bought me a 'broken' one…
... [*]8x fried upper ram
[*]Power coil likely broken (no noise ... a lot more may need replacing, I figure I'll ... start by replacing the coil, TR4 and ... if I can get the power rails back to where ... this works, look at replacing the RAM and ULA and ... -
Modern PSUHello everyone, I'm looking for a modern PSU for my Spectrums and my dual set of 3.5'' floppy drive+HxC floppy emulator. The one for Spectrum should …
... wire and without any feedback circuit between the primary and ... input. With the feedback circuit you can use optical feedback ... if fed to a regulation circuit. The advantage is that ... circuit protection will be an added benefit. Over current and voltage power ... -
Modern PSUHello everyone, I'm looking for a modern PSU for my Spectrums and my dual set of 3.5'' floppy drive+HxC floppy emulator. The one for Spectrum should …
... nominal 9V DC unregulated external power supply unit (PSU). So if ... limiting (over current/overload/short circuit protection) is part of the ... -
Modern PSUHello everyone, I'm looking for a modern PSU for my Spectrums and my dual set of 3.5'' floppy drive+HxC floppy emulator. The one for Spectrum should …
... 12v...[/QUOTE]
The circuit for the internal DC-DC ... not have the improved internal power circuitry and don't use ... any power supply that has a on ... -
UK National Grid StatusInteresting. I thought so anyway. [url]http://www.gridwatch.templar.co.uk/[/url]
... it's certainly source of power that's going to fluctuate ... the prospect of renewables ever replacing coal and nuclear, which provide ... -
UK National Grid StatusInteresting. I thought so anyway. [url]http://www.gridwatch.templar.co.uk/[/url]
... it's certainly source of power that's going to fluctuate ... the prospect of renewables ever replacing coal and nuclear[/B], which ... -
UK National Grid StatusInteresting. I thought so anyway. [url]http://www.gridwatch.templar.co.uk/[/url]
... 'll give you very little power some of the time and ... as part of a diverse power grid but, unless we're ... technologies to supplement them in replacing fossil fuels and nuclear power. -
How important is the 9V line?I'm in the middle of resurrecting an Opus Discovery. The transformer is gone so Im using a small switched mode PSU from a PC. My plan is to bypass …
... .
Now, the -5V power... Am I correct in thinking ... , does anyone have a good circuit diagram for the Opus Discovery? -
PlusDlite v2014.1 - problems with floppy power supplyI received a small batch of boards of the new PlusDlite design, which is similar to the original PlusD, with GAL etc. The main differences with the o…
... problem is solved!
Replacing the 74HCT126 with this LS ... the problem with the external power supply for the floppydrive.
power supplies, than the LS ones ... -
Dodgey R62 / D16 on Issue 2?Hello all, I am still beavering away trying to work out why my Issue 2 fails and after a much closer visual inspection I noticed what looks like som…
... .
After replacing these parts, check all three power rails +5V, +12V ... damaged to me. If the power rails test okay, then D16 ... -
UK National Grid StatusInteresting. I thought so anyway. [url]http://www.gridwatch.templar.co.uk/[/url]
... it's certainly source of power that's going to fluctuate ... the prospect of renewables ever replacing coal and nuclear, which provide ... energy needs from wind power alone. It sold power to the European ... (think it was Monday) wind power generated 15% of the UK ...
