You can disassemble the C64 DTV quite easily. The main board looks like this:
You can use a 7805 for regulation to 5V, this allows you to use an external power supply with about 7.5V. In my DTV, it is connected directly to the jack. Ground is being switched using the built-in switch of the jack.
Following instructions that can be found on the web, you can attach an PS/2 keyboard to your C64 DTV. Connect the clock line to the via next to R3, data line to the via next to R4. These vias have to be cleaned and have the coating removed in order to be soldered properly.
You can take GND from anywhere on the digital ground plane, for instance on the pad on the back of the board next to the power supply wires. Vcc can be taken from the corresponding power supply line. Attention! Fresh batteries could cause a Vcc of > 5.25V which my damage your keyboard. Use Ni-MH rechargeable batteries or the 5V regulator mentioned above.
The instuctions for the color fix can be found here: http://www.kahlin.net/daniel/dtv/colorfix.php. This fix is needed because the people building the PAL version haven't understood the R-2R D/A converter.
In my fix, I have used 680 ohms instead of 600 ohms, because I only have a SMD resistor set with E24 values. You then have to change 300 ohms to 340 ohms, but I used 330 ohms for the same reason.
Remove all resistors, clean pads using solder sucking wick, then add little amounts of tin to every pad. Place resistor on pads, solder from one side, solder from other side, e voila! I didn't have 0603 resistors at home, so I used 0805. I had to treat them as quasi-2-pin-BGA components and have quite little space left between the resistors, but it worked. I mounted the two extra resistors "standing" on the ground plane and wired their second end to the corresponding joints.
last edited 12.08.06 by hennichodernich
