I have a small and closing gap to do a serial port program before I get back to a design I'm doing for an inventor. Anyway this is the scoop. I am using a 56K PCI MODEM card. It is designated at Com port #3. WHen I go to Control Panel/Device Manager/Modem I look at specs to see that the I/O addresses are at D000 t0 D007. I have given permission correctly to a user mode program so there is no exception generated as per Four-F's instructions. I can read the I/O ports but I when I attempt to access this port I always get "ff". I have done frantic research and even found my particuliar brand of PCI modem card documentation which is Rockwell-Conexant and they state that Comm3 is at I/O address 3220. I tried that too with same results. I also tried traditional 3E8 address and same thing. I think I found memory buffer at 1000h (2k) and 2000h (2K) as they change constantly when on internet:
00001000 CA FA A4 F9 FC FC 77 01-8F 03 3B 05 43 09 33 0C ......w...;.C.3.
00001010 95 06 C8 F7 BD EA D1 EB-5B FA 5E 07 C7 05 77 F9 ........[.^...w.
00001020 56 F1 D8 F3 79 F8 B1 F6-B7 F2 16 F6 DA FF 19 06 V...y...........
00001030 51 05 4C 04 BB 05 C8 01-50 F4 F4 E8 C5 ED E6 FD Q.L.....P......

00001000 2E 00 D0 0F 71 0F B2 04-27 FD 80 FA 80 F7 45 F4 ....q...'.....E.
00001010 F0 F5 BF FA 68 FC C1 FB-BA FD 5E 00 94 FE 95 FB ....h.....^.....
00001020 C1 FF 28 08 45 07 8A FA-4A F1 1E F6 33 FF 7D FD ..(.E...J...3.}.

One address is xmt and one rcv I assume. I would like to verify this by reading the 16 byte FIFO and the UART it's self by polling methode at first. "Back off f0dder there is a methode to my madness". Does anyone have a handle on these multi I/O PCI shared interrupt MODEM cards?
Posted on 2004-01-29 17:00:21 by mrgone
This link explains it all. http://www.net-boy.com/

Software modems. The El cheapos. No wonder there's such a miriad of drivers even for each version of operating systems. Very interesting and informative link non-the-less.
Posted on 2004-01-30 09:36:35 by mrgone