I want to make a software which can send message to others from pc through a usb (attached to computer) and usb is having a sim card in it.I have searched a lot but couldnt find any API which can provide access to the sim in that usb.any Gsm sim card can be inserted into usb. Can any one help me out in finding this API I will be greatful.
Are you talking about a HSDPA access device as in this link. If so, you need to send/receive AT commands to USB port. If this is the case, let me know so I can help you further.
Well its not exactly similar to it but a sort of.I will be connecting a normal USB device (Sim Card is inserted into it,see the picture link )to USB ports of the computer and then i am planning to use AT Commands to communicate (Send/recieve both) with it. So you can help me in this regard and i Am really thankful to you.
I'm clear now. It is a usb sim card reader. The product page that you have given doesn't contain any technical detail about the protocol. However I'm sure it uses PC/SC standard. See this link for a similar product that supports PC/SC standard. The basic technology for communication between personal computers and smart cards is PC/SC, defined by the PC/SC Workgroup. PC/SC Workgroup - Developer Downloads contains lots of information required for you on communicating with this device. MUSCLE is a nice group that develops a driver under linux and some other OSs. They provide driver source codes, etc... - Go to (Information -> Tutorial) for command set, etc... - Go to (Software) for Drivers, source codes, etc... I'm sure now you have enough to give a start. Taken from here.