CONNECTING A STAMP TO A LAPTOP COMPUTER

ver: 03-apr-00

Some laptops have difficulty communicating with the BASIC Stamp 1 because their parallel port does not have sufficient voltage drive. Symptoms are "Hardware Not Found" errors with a Stamp board and cable that work when connected to a desktop computer.

To remedy the solution, you need to construct a special Stamp interface cable that boosts the voltage drive of the laptop parallel port to acceptable levels. The key component is an optical isolator.

Construct the cable by direct soldering to the 4N35 pins and to the resistors. After testing, wrap the whole thing in gobs of electrical tape to prevent shorts.

Happy Stamping!