If you've got a Pocket Mini Computer Kit, you've probably noticed that the "Experimenter's Port" on the right side is labeled P12-P14. The reasoning for this is that the Propeller microprocessor (The CPU used for this project) has a lot of great existing games and programs already written that support TV output.
This Instructable will teach you how to create the "World's Simplest Video Card" for your Pocket Mini Computer.
Don't know what a Pocket Mini Computer is? The Pocket Mini Computer is a simple open source computer that runs an 80's style BASIC that you can build from scratch or assemble from a kit. For more information on the PMC project, see this Instructable.
Step 1: Required Hardware
- Parallax RCA Breadboard Adapter
- 1.1k resistor (Brown, Brown, Red)
- 560 ohm resistor (Green, Blue, Brown)
- 270 ohm resistor (Red, Violet, Brown)
- 5pin male, right-angle header
- A small piece of "perf" board
- A piece of wire.
The perf board I used was cut down to 7x11 rows.
Take your time while building this project, while it's a simple board, it's fine work.
Step 2: Making the Connections
Insert the resistors as shown in the photograph:
(From left to right, facing forward)
- 270ohm (Red, Violet, Brown)
- 560ohm (Green, Blue, Brown)
- 1.1k (Brown, Brown, Red)
- Solder each resistor to one pin of the right-angle header at the bottom (see backside picture)
- The other side of the resistors all connect to "SIG" on the Parallax RCA Breadboard Adapter
- Skipping a pin, connect the 5th pin (Vss) to "GND" on the Parallax RCA Breadboard Adapter
Step 3: Testing the Circuit
Insert the board with the RCA connector facing outward and toward the rear of the Pocket Mini Computer.
Open the Propeller Tool, and load Graphics Demo from the "Propeller Library - Demos" on the left panel.
Press F10 to send the program to the RAM of the Pocket Mini Computer.
You should see a screen that looks like the picture.
If the colors look wrong, check to make sure each resistor is soldered into place, and that none of them are touching at the bottom side where they connect to the pin header.
Want a version of COLOR BASIC that works with the TV?
Here's both TVBASIC.BIN and the source for COLOR BASIC version L converted to TV.
(There's also a number of compatible game binaries. (and their sources) in the same folder.) -Enjoy!!