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tim.

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About tim.

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    Australia
  1. tim.

    Atari 2600 RGB mod

    I don't recommend it. If you bend the pin away then bend it back the metal will have fatigued and the pin may break off. If you are dead set on doing this make sure you remove the TIA, bend the pins, then solder it back to the motherboard. It's made from high temperature polymer. You won't put your soldering iron through it any faster that you'd put it through a fibreglass PCB. With the current PCB layout I would have had to use an adapter board. The combined height of a socket + pins + adapter board + pins + 2600RGB is too heigh to fit into the space available, even if the TIA was soldered to the 2600RGB board. The only options were to have a different board design for the Jr model or use a flexible adapter. The choice was pretty clear to me... The need to cut some chip pins is unfortunate, but it is safe and easy compared to trying to desolder the TIA.
  2. tim.

    Atari 2600 RGB mod

    It's not the they don't fit. I need to connect to these four signals on both the TIA and the motherboard and break the connection between. This way the 2600RGB board can (slightly) modify the data that is sent to the PPU.
  3. tim.

    Atari 2600 RGB mod

    The 2600 Jr. version of this mod is available now.
  4. tim.

    Atari 2600 RGB mod

    These machined pin headers are round. They don't fit well in a dual wipe IC socket because it's designed for a pin with a flat side, not a round one. If you use the round pin headers you might have connection problems and it may not be able to hold the weight of the 2600RGB board in the socket without falling out. A round pin header in a round pin socket makes the best connection, but when the dual wipe socket is provided, the square pin header is the one to use.
  5. tim.

    Atari 2600 RGB mod

    Driving controllers are fine, they don't connect to left/right at all. From brief research, it appears a 2600 trackball or supporting games don't actually exist (???).
  6. tim.

    Atari 2600 RGB mod

    The first 128 bytes is the header. It's not used so just set all values to zero. Then just append palette files as needed. A palette file is almost the same format as the Stella emulator uses. The only difference is there is no SECAM palette information. For reference, The palette file must be 768 bytes long. Colours are stored in 24-bit RGB, with the first byte for red, the second for green, the third for blue, for a total of 3 bytes per colour. The first 384 bytes of the file (128 * 3) will be used for the NTSC palette. The next 384 bytes (128 * 3) will be for the PAL palette. Minimum 1 file, maximum 6 files. If the next palette it tries to load is set all to 0xFF then it assumes it's at the end and wraps around. Current user selected PAL and NTSC palettes are remembered separately.
  7. tim.

    Atari 2600 RGB mod

    No, you misunderstand. Pressing the extra button on the controller is the equivalent of pressing both left and right on the joystick at once. It doesn't do anything at all by itself, only in combination with one of the three other signals. For example, to change the palette press extra + fire (equivalent to left + right + fire). The 2600RGB doesn't interfere with any 2600 controllers that I could find documented. I've attached an audio buffer circuit you can build. It's made from a cheap dual op-amp and some passive components. It's not so simple. There's very little space in the Jr model so the TIA must remain attached to the PCB.
  8. tim.

    Atari 2600 RGB mod

    The pins are open collector outputs so a pull up resistor to the +5V supply is required to get any output. I don't recommend connecting the pin straight to the outside world like this. It's too easy to damage the TIA because there's no protection from ESD and other environmental dangers. Ideally, you should use a buffer-amplifier between the two audio signals and the outside world. It can be simple, a pair of transistors or dual op-amp would do.
  9. tim.

    Atari 2600 RGB mod

    I will have one eventually, but not in the immediate future. It's different to my usual adapter board. To fit in needs to be made from flexible material and fold around the edge of the motherboard. It's a different process and a bit more expensive. The 'stereo' audio was deliberately not included. The vast majority of games were not designed with a thought to sound channel separation. Whether it sounds better or worse with the separation it just a matter of luck. It's also not possible with PAL consoles.
  10. tim.

    Atari 2600 RGB mod

    You can try installing it if you can't wait, just be aware that the replacement board does not come with any other parts from the kit. The bug is related to the clocking system. During the start up process the main clock is switched from the internal RC oscillator to the PLL. The original software had a timeout on the PLL. If it did not lock within a certain period of time it would got to an error handler which was just an infinite loop. It was hidden in some library code so I didn't know about it previously. I don't recommend using the buggy version in a permanent installation because it relies on the speed of the Atari's oscillator start up and this can change with factors like temperature. The most obvious sign that you are seeing this bug is the LED on the 2600RGB board doesn't blink when the power is switched on. Normally it blinks once for a NTSC console, twice for a PAL console. Anyway, if it doesn't start you can get it going with a manual reset. There is a 5 pin programming header (at least plated holes for one) next to JP2. Pin 1 is marked with a circle. Switch the Atari on, then momentarily short pins 2 and 3 with something conductive. The 2600RGB board should now start and blink the LED. You will need to press reset on the Atari to reinitialise the game so the colours are correct. A few games won't work properly this way. For example Ms Pacman only draws the maze once at power up, not on reset.
  11. tim.

    Atari 2600 RGB mod

    I have put some photos up here http://etim.net.au/2600rgb/screenshots/ One is from the Stella emulator. The other two were from this forum - the Nabuko palette and the Trebor palette. I have uploaded them all here for you to try on your favourite emulator.
  12. tim.

    Atari 2600 RGB mod

    Yes. I'm not working on it currently, but it's fairly high on the priority list. Sometime next year probably. I don't think anybody's going to price it before they've done it. I don't offer installation services myself - I'm too busy and too far away. It's already compatible. The usual warning of "don't expect it to work on a HDTV" applies. I'll put some up on the web page tomorrow.
  13. tim.

    Atari 2600 RGB mod

    Hello everybody. I'm Tim Worthington, creator of this mod. You can disable the automatic PAL/NTSC palette switching. It's possible to use the original RF output. You need to hold how the palette button while switching on the console. This effectively disables the 2600RGB board operation and lets the Atari work as it did before. There's no 'stereo' sound separation feature because it does not work on PAL consoles and I personally don't think it's much of an improvement. Anybody is welcome to order from me directly, but be aware that I am in Australia. If you are in the US, I do recommend taking advantage of the US distributor section, fulfilled by Yurkie, as you will receive your order faster (and cheaper) this way.
  14. For anybody interested in some of the technical details of these things, I have a page dedicated to just that. Sega Master System/Game Gear clone ASIC page
  15. tim.

    Joystick rebuild

    I've fixed a few atari joysticks, the problem is the cheapo metal button things are held to a piece of citcuit board with tape and this tape comes off and the buton stops responding (be it left, right, up, down or fire). I don't think you'd need metal discs form ebay to fix it. but the standard atari joysticks are pretty crappy to begin with...
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