for Notebook with Mini PCI slot

PCI one chip solution( SystemBase SB16C1052PCI)

It's real COM Port in your computer, not USB to COM port
  high compatible with serial type device.

Mini PCI 2 Serial  RS422/RS485 in  Windows XP Device Manager

* Fully compliant with PCI Local Bus Specification Rev 2.3
* Built-in TWO IMPROVED  16C1050 UART with 256-byte Deep FIFO128K byte DMA software FIFO
* Software/Hardware Flow Control & Xoff Re-Transmit Function
* Easy Plug and Play Installation
 
System Requirements:

 * Windows® 98/2000, XP, Server 2003 ,Vista ,Win7 and Linux 2.4& 2.6

 * Mini PCI slot

Accessories:

1 x Manual, 1 x Driver CD, 2 x 9pin serial cable