We are developing an application that needs an interface to a satellite communications modem (5 kHz DAMA). The modem requires synchronous communications and uses modem control lines, RTS and CTS, for accepting input data from the application. The host platform for the application is Windows NT. An NT solution would need to include a synchronous serial device (ISA, PCI, or PCMCIA) and an NT kernel mode device driver. We identified several candidate devices but none with NT device drivers. I found the list of NT device driver development requirements, i.e., versions of NT, development subscriptions, toolkits, etc. a bit more than I wanted to deal with. Since we have not been able to find an NT solution for the required interface we have been exploring Linux possibilities. I developed a pipe-like application that passes data between a socket and a serial device to allow the NT application to talk to the modem over a network. Our current test suite utilizes this pipe-like application running on a Linux box that talks asynchronously, using the linux serial driver, to the modem via a synch/async converter. This works fine except for the start and stop bits inserted in the synchronous data stream. Other devices that our application will communicate with will be synchronous and won't know what to do with the asynch framing bits. We have concluded that we should build/buy a synchronous serial device and Linux device driver. While writing a device driver is far removed from my expertise I have bought Rubini's book and I'm entertaining the thought of making the attempt. I don't really want do reinvent the wheel. Does anyone know of an existing synchronous serial device and driver that we should investigate? My approach to device driver development will be to start with an existing driver, e.g., serial.c and modify it for the TBD synchronous device. What are the pitfalls with this approach? I noticed that some of the Linux network device drivers support synchronous devices. If I do attempt to write a driver would it be better to start with one of the network drivers or the serial driver? Do software toolkits that support Linux device driver development exist? Can anyone recommend sources: information, people, and/or companies that might help? Any comments, requests for clarification, and/or corrections about faulty statements are also welcome. -- john ------------------------------------------------------------------------ John Florence, Mathematician, VSS Group, 25-162 Phone: 240-228-6685 JHU/APL, Johns Hopkins Road, Laurel, MD 20723 FAX: 240-228-6663 [EMAIL PROTECTED] - To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to [EMAIL PROTECTED]
