Atari Video Touch Pad
The Atari Video Touch Pad was bundled with the Star Raiders cartridge for the Atari 2600. It connects to an Atari-compatible control port and the Commodore 64 can be programmed to use it.
Keypad[edit | edit source]
Like the built-in keyboard, the keypad on the controller is wired as a matrix of switches. It has four rows and three columns, and the switches are arranged in the obvious way: the switches in each physical row have the same row connection, and the switches in each column have the same column connection.
Connector[edit | edit source]
The connector uses all seven I/O pins on the control port. The four pins for the joystick direction connect to the rows. The pin for the joystick button and the pins for the paddles connect to the columns. The column pins that connect to paddle inputs have 4.7 kilohm resistors connected to the +5V line.
Because the paddle pins can only function as inputs, controlling software must drive the rows as outputs. This usage is contrary to how the joystick works; but the pins are directly connected to the CIA with no buffering, so the pins can be reconfigured without any problems.
The connector connects to the keypad as follows. Rows are numbered from the top, and columns from the left.
| Pin | Signal | Joystick | Remarks |
|---|---|---|---|
| 1 | Row 1 | Joy A0/B0 | |
| 2 | Row 2 | Joy A1/B1 | |
| 3 | Row 3 | Joy A2/B2 | |
| 4 | Row 4 | Joy A3/B3 | |
| 5 | Col 1 | Pot AY/BY | |
| 6 | Col 3 | Button A/B | |
| 7 | + 5V | 4.7 kΩ pullup to 5 and 9 | |
| 8 | GND | Not connected | |
| 9 | Col 2 | Pot AX/BX |
Emulated SIDs[edit | edit source]
Two of the columns connect to paddle inputs. Some emulated SIDs do not support the paddles. These will not support the Video Touch Pad, either.
