Hello all, my mind's been getting rusty lately, I need information on programming the comm ports directly (hardware level) and hopefully also be able to do autodetection of any modems and comm ports (including IRQ's).
Now what I remember is that the I/O ports are located at pretty standard places, and that in general I want to be able to respond quickly to received characters (which means using IRQ's). Each port has four registers I think, but they take up 8 addresses because they're repeated (I think). They used to have pretty standard IRQ's but no longer.
Now my idea of autodetection of IRQ's is to first determine the I/O addresses (which are pretty standard) and setup a loopback function, then trap each candidate IRQ and send a byte, which should be received immediately and call the IRQ. Is this process correct? How stable is this operation? How reliable is it?
Detection of modems I think should be easy, just send "AT\0xd\0xa" and check if you received an "OK".
"Information has a tendency to be free. Which means someone will always tell you something you don't want to know."
Now what I remember is that the I/O ports are located at pretty standard places, and that in general I want to be able to respond quickly to received characters (which means using IRQ's). Each port has four registers I think, but they take up 8 addresses because they're repeated (I think). They used to have pretty standard IRQ's but no longer.
Now my idea of autodetection of IRQ's is to first determine the I/O addresses (which are pretty standard) and setup a loopback function, then trap each candidate IRQ and send a byte, which should be received immediately and call the IRQ. Is this process correct? How stable is this operation? How reliable is it?
Detection of modems I think should be easy, just send "AT\0xd\0xa" and check if you received an "OK".
"Information has a tendency to be free. Which means someone will always tell you something you don't want to know."
