5. Results

5.1 Performance

The game performs well despite the limited amount of video that is updated in each frame. We allocated almost all of our available 2048 bytes of SRAM to program variables and used nearly 50% of the 32 Kbytes of flash. The explosions that are drawn for intercepts are executed smoothly without a noticeable flicker.

5.2 Safety

From the designer's perspective, the circuitry involved uses voltages below 15-V and there are few connections that have to be made beyond the prototype board circuitry. Once this is completed, the game designer uses exposed wires to connect the signal generation pins on the prototype board to the television. However, these wires are safe to touch and there is no excessive electrocution risk. Structurally, the components are small and safe to handle.

5.3 Interference

The noise emitted from our signals is not enough to interfere with FCC regulated transmission, so we are not concerned with interfering with RF devices. However, our game may interfere with the player's motivation to do something more productive with their time. Nevertheless, this is a small price to pay for such a valuable historical teaching tool.

5.4 Usability

Missile Command is easily usable by sighted individuals with average motor control. Although the title, menu, and score information is written in English, the simplicity of the interface and intuitive nature of game play makes it likely that anyone will be able to pick-up the game quickly. The two MCUs are attached together and are easily portable. This hardware can be connected to any NTSC television with an appropriately spliced video-in connection. The hardware also interfaces with a standard PS/2 mouse.