I have a legacy dos program that reads/writes on serial ports com1-com4 using phyisical port addresses(0x3f8, 0x2f8, 0x3e8, 0x2e8). But to read from com5 port onwards where can I get port addresses information?
While DOS allows to add more COM ports, proprietary drivers are needed since the system supports 1-4 by its own. Anyway if you are running your legacy application under Windows XP NTVDM subsystem, you are forced to access COM1 - COM4 only and that is just magic, believe me.
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