CableMAX CM-4S1PRS232 4S1P PCIe x1 expansion card

Legacy I/O expansion

The CableMAX CM-4S1PRS232 is a PCI Express x1 add-in card that adds four RS-232 serial ports and one IEEE1284 parallel port to a desktop system. It targets integrators and technicians who must connect legacy industrial equipment, point-of-sale hardware or older peripherals to modern motherboards that lack native COM and LPT headers. The card fits any standard PCIe x1 slot and operates with 5V or 3.3V signalling tolerance.

Sustained throughput

Each of the four UART channels uses a 16C950-compatible controller with 128-byte FIFO buffers per transmitter and receiver, supporting baud rates up to 921.6Kbps and automated in-band and out-of-band flow control. The PCI Express 1.0a interface delivers full x1 throughput of 250Mbytes/sec, so sustained multi-port traffic does not saturate the bus. Advanced error reporting with ECRC support helps maintain data integrity during long transfers.

Port count decides fit

The single specification that determines suitability is the combination of four serial ports plus one parallel port on a single bracket. Systems that need fewer serial channels, a different connector type or no parallel port should select an alternative card, while applications requiring more than four COM ports will need additional expansion.