Please excuse me for replying in English...
It seems that linking via Google translate doesn't always work, here's the page untranslated:
Painkilla's blogIn case neither this work, then go to the bottom of that page and click on
page 14 of the blog.
Where did you find that schematic ? I'd like to know more about how it works. Thanks
Ok, so in that blog it refers to a MSX forum (Paran... something) which unfortunately can't be browsed without a registration, anyway with the thread name (in korean characters) and a few key names I was able to get the schematic.
How does it work?
The first chip (74LS74) is connected to the H sync of the VGA connector and its output changes state every time there's a new H pulse.
The switch (TL32PO) selects if we want to erase the even or the odd lines
The 2nd chip (74LS125N) connects the R,G and B lines to GND (so it produces a black line) when there's an active pulse coming from the first IC.
If someone wants variable dimming (instead of just ON/OFF) has only to add 3x potentiometers between GND and the input pins of the '125.
Pas la source des composants à utiliser, ni du schéma de montage par contre.
Components to use are 2 ICs named above and a switch for a basic ON/OFF effect, a complete schematic isn't really needed as it wouldn't be much more than the above.
I can show you a couple photos of a built circuit:
But don't be intimidated by all the wires, it looks more complicated that it really is. Most of the wires visible are needed to bring the signal from one VGA connector to the other.
Sharksym is the person who designed the circuit above, and this is the page of his blog from where the 2 pictures above were taken (sorry but also in Korean):
Sharksym's Blog
