I have been trying to get what I believe to be a pl2303 serial SIM card reader/ writer to work under Linux Mint for a while now. I used it on a friend's windows computer and it worked fine. I tried WINE but no detection of hardware. All tutorials say that the driver has been in the kernel for sometime, however, I cannot access the device. Any ideas?
Below is the printout of dmesg|tail involving the device:

[ 1951.908690] pl2303 2-1.4:1.0: pl2303 converter detected
[ 1951.912779] usb 2-1.4: pl2303 converter now attached to ttyUSB0
[ 1954.373493] usb 2-1: USB disconnect, device number 2
[ 1954.373499] usb 2-1.1: USB disconnect, device number 4
[ 1954.374228] usb 2-1.4: USB disconnect, device number 5
[ 1954.377346] pl2303 ttyUSB0: pl2303 converter now disconnected from ttyUSB0
[ 1954.377374] pl2303 2-1.4:1.0: device disconnected
[ 1955.072030] usb 4-1: new full-speed USB device number 2 using ohci-pci
[ 1955.256027] usb 4-1: device descriptor read/64, error -62
[ 1955.540024] usb 4-1: device descriptor read/64, error -62

As the first line reads it seems to be detected and `lsmod|grep pl2303`
shows both kernel mods pl2303 and usbserial have been activated; still running too after device removed......ANY IDEAS??? I just need a direction, or a wonderful answer and a GUI access, but command line will do. Any help would be greatly appreciated.

Being found but disconnected suggests to me that the driver isn't available to be associated/loaded.

Take a look in /lib/firmware for a driver, if not there, you probably need to download/install it.

Looks like some SIM card readers appear as a USB serial port device to the host computer. At the moment it appears to be working and it is up to the application to access the device. A quick google did not find much searching for software. I did find monosim. http://monosim.integrazioneweb.com/

Thanks for the advice, I'll try and get back to the thread, I have heard that the pl2303 driver is in the kernel (and it is) but that some of these devices from China are pl2303x and do not work with kernel driver. I have found a patch that claims to fix it and I am working my way through the code just to be sure it really is a patch not some nasty virus.

Also, when running monosim-gtk I get the following error messages in return :
/dev/ttyS0 = WRONG RESPONSE [9F??] []
/dev/ttyS1 = WRONG RESPONSE [9F??] []
/dev/ttySX = Input / Output error

This leads me to believe the device is showing itself but perhaps I have the settings wrong...been a long time since I worked with serial port, real or make believe. Clearly though it is on /dev/ttyS0 or /dev/ttyS1 . any idea how to "talk" to a serial device command line? Thanks again.

ttyUSB0 is ID for the device and you can use minicom to communicate with it. cutecom is another terminal program for sending binary data.

Established contact with device using minicom on ttyUSB0 and ttyS0 (they seem to be linked somehow ln -s or something). But thanks, cutecom has allowed a graphical system that is more flexible then monosim, though I am continuing to try
to get monosim to work. Thanks for your quick help. I consider this issue resolved. Thanks again. If anyone else is featuring similar issues please feel free to contact me for old log files, config files etc. open source works best when we all have our minds open.