Adapter-attached asynchronous ports

Each of the adapters requires a bus slot and can only be used in systems that support the required bus type.

The 128-port, ISA 8-port adapters, and PCI 8-port adapters are intelligent adapters that provide significant offload of the main system processor.

EIA 232 is the most common communication standard, but the EIA 422A (used when a longer cable distance is needed) is also supported. The EIA 422A implementation does not include device status detection capability or RS 232 modem control signals.