LIBERTY,Sealevel Systems, a South Carolina firm that provides serial and digital input/output (I/O) solutions, has developed four new serial adapters for mobile computing applications.

The cards add a variety of mobile communications capabilities to personal data assistants and other devices that don’t have serial ports. Each offers low power consumption and easy installation, Sealevel said. Prices begin at $119.

Sealevel said the devices are compatible with various Windows platforms.