I built this Hummer for a friend of mine who is a huge Commodore fan.
I honestly had no idea how to use it or program the thing.
Description of components and mods:
Box for the DTV:
- I used 1/2" oak since that is what I had lying around. The outer dimensions are 5" x 5" x 2.5" which gives an interior size of 4" x 4" x 1.5". Because I used such thick wood, I had to use connectors that were mounted from the back rather than the front. Glue keeps the connectors from being pulled out. If a thinner material is used, remember to add enough space for the back of connectors sticking out over your board. The IEC connector is the deepest at around 3/4". With a plastic box I'd add at least 1/2" all around.
- Really easy to do. I first of all made sure there was no resistance across the resistor. Obviously, with a resistor there you're supposed to get some resistance. I simply removed the resister, cut the line underneath, and soldered it back. Remember to check with an ohmmeter to make the line underneath is still cut.
- I bought the 681 ohm resistors from Fry's. Remember, 681 ohms, not 681k ohms. It was easier to take the 3 681 resisters from the bottom and swap them with the 3 331 resistors from the top rather than replacing all 5 681's. The 681's I bought were very large and had trouble fitting on the soldering pads. I found the best way to make sure they contact is to add some more solder onto the pads before attempting to set them down. A very large minifying glass with alligator clips for delicate soldering work really comes in handy. It's very, very easy to lose those little resistors. I found laying down a cloth on the workbench made it easier for me to see the resistors if they fell down. I used a craft knife to move the resistors around. This was probably the most delicate work I've ever done. I thick I spent close to 3 hours messing around before I got it all done. Note to self: don't drink so much caffeine that your hands shake before doing this fix.
- I removed the potentiometer because it was sticking far out the back. I can't see any reason why I would need it.
- Stereo jack - I found that just hooking up a regular stereo jack was easier than hooking up a left and right RCA jack. I suppose I could have used just one RCA but it didn't seem as clean of a design. Besides, it's a bit confusing to use an RCA jack if you're not going to use composite video.
S-Video - so much nicer of a picture than composite. Definitely do this mod. I did find that even without the video fix it looked a lot better than the composite signal.
IEC (floppy) connector - pretty straight forward to hook up. The reset switch is connected to the IEC reset line and ground.
Keyboard - hooked up to the 5v power supply.
Joystick - hooked up to the userport lines 0 to 4 and ground.
Power Jack - I used a standard type "M" DC power jack with a 5v regulated power supply.
Power Switch - the Hummer uses a special power hook up than normal. I used a double pole, double throw switch (6 solder points on the bottom). One side of it is connected to the battery +5v line and to the other devices needing 5v (in this case just the keyboard and a power indicator LED). The other side I connected to ground, L- (on), and DIS (off).
Reset Switch - connected to RST on the board and to ground. I highly recommend one since you'll often have to reset once or twice to get the keyboard working properly. Sometimes on startup you'll hit the Basic screen but the keyboard didn't initialize properly. It's possible that I wired it wrong but I had this same problem on the DTV 1.
- With DC current there's no difference between the negative line and ground. To make my life easier I just connected one component to the next around the box and finally to the DC jack. After I did the ground lines, I hooked up the 5v lines. From the DC-in jack, I connected a line to the power switch. From the power switch, it went to the keyboard and power-on LED. LED's are completely optional and really don't serve much purpose. Keep the Hummer's LED because it won't work without it. Next, I made all the connections on the board. If you buy at least 26-gauge wire you can poke them through the other side and solder. For the userports I had to hot glue the solder joints to avoid breaking them. I found that using solid wire was easier to work with, especially poking through the board. Once the glue is set you can bend the wires around to where you want them to be and they'll stay. Finally, I put the board in the box and hooked up the connectors. I found it is best to start with the video and test it. Then proceed to sound and keyboard. Once the keyboard is connected, you can test the floppy drive connection. Feel free to use a lot of hot glue. You don't want anything to fall out or rattle around. The jacks have to stand up to a lot of abuse shoving plugs in and out. I found that the glue melts quickly off the components using a soldering iron. Don't ever try to remove a hot blob of glue with your hand. You end up with glue all over you and it burns very badly.