In 1984, Tom O'Hanlan designed the first RS-422/485 communication adapter for the IBM PC. From that moment of inspiration, Tom and his wife Susan saw an ever-growing industry-wide need--and began work to fulfill it. In 1986, they formed Sealevel Systems committed to providing communication adapters for the IBM PC and compatibles. Today, they manufacture more than 300 standard I/O products with ISO 9001: 2000 registration and a standard lifetime warranty.