Ubuntu comes with most USB to RS232 drives, all we have to do is find the device name that corresponds to the device.
Enter LSUSB under the terminal to list the USB devices identified by the system
$ Lsusb
Bus 008 Device 001:id 1d6b:0002 Linux Foundation 2.0 root Hub
Bus 003 Device 002:id 064e:a103 suyin Corp.
Bus 003 Device 001:id 1d6b:0002 Linux Foundation 2.0 root Hub
Bus 007 Device 001:id 1d6b:0001 Linux Foundation 1.1 root Hub
Bus 006 Device 001:id 1d6b:0001 Linux Foundation 1.1 root Hub
Bus 005 Device 003:id 062a:0001 Creative Labs Notebook optical Mouse
Bus 005 Device 001:id 1d6b:0001 Linux Foundation 1.1 root Hub
Bus 004 Device 005:id 067b:2303 Prolific Technology, Inc. PL2303 Port
Bus 004 Device 001:id 1d6b:0001 Linux Foundation 1.1 root Hub
Bus 002 Device 001:id 1d6b:0001 Linux Foundation 1.1 root Hub
Bus 001 Device 001:id 1d6b:0001 Linux Foundation 1.1 root Hub
Enter DMESG to display the connection device name (red font part)
[668.252084] USB 5-1: New full speed USB device using UHCI_HCD and address 2
[668.413928] USB 5-1: Configuration #1 chosen from 1 choice
[668.692862] usbcore:registered new Interface driver usbserial
[668.692900] USBSERIAL:USB serial support registered for generic
[668.692968] usbcore:registered new Interface driver Usbserial_generic
[668.692973] USBSERIAL:USB serial Driver Core
[668.704495] USBSERIAL:USB serial support registered for pl2303
[668.716444] USB 5-1: pl2303 Converter now attached to ttyUSB0
[668.716491] usbcore:registered new Interface driver pl2303
[670.016108] USB 5-1: USB Disconnect, Address 2
[671.008120] USB 4-1: USB Disconnect, address 4
[672.740055] USB 4-1: New full speed USB device using UHCI_HCD and address 5
[672.904865] USB 4-1: Configuration #1 chosen from 1 choice
[672.928071] USB 4-1: pl2303 Converter now attached to ttyUSB0
Use this device name in minicom
from:http://99dev.net/archives/564