Available in three versions, the 4I32 consists of a high-performance, four-channel asynchronous serial port on a stackable PC/104 card. It comes as a quad RS-232, quad RS-422/485, or as a model with two RS-232 and two RS-422/485 channels. The card uses enhanced 16C550-compatible FIFO UARTs with many added features. The UARTs have 128-kbyte receive and transmit FIFOs for lower overhead or to support higher baud rates, which are supported with RS-422 or RS-485 and up to 230K baud with RS-232 models. The UARTs also support automatic hardware or software flow control. Automatic direction is provided for half duplex RS-485 type applications. Each of the four serial ports can use any of the 11 available AT bus interrupts. The product can be operated in full duplex or half duplex RS-485 mode and requires 5V for operation. Pricing is $135 each/100.