mjohnm

I need to detect programmatically the base address of parallel ports. It is not neat to have my users go to the hardware setup to determine such addresses. My software in VB6 should be able to run on any Windows varant since W95.

I have found some libraries that claim to do this, but they do not detect non-standard base addresses (e.g. >&h8000 for PCI cards) and appear to read the old DOS BIOS equipment information (which still exists under XP!!!) The BIOS information (1) does not support non-contiguous LPT assignments (on one of my machines Windows had assigned the two parallel ports to LPT1 and LPT3 with no LPT2) and (2) might disagree with Windows (one of my machines had a CMOS setting that was different from the setting Windows had assigned - the DOS equipment area had the CMOS base address)

I can detect which ports are known to Windows using the CreateFile API call, but do not know how to get the base address for each port found.

Thanks for any help,

John

BillSoo

Hmm..... that's a tough one.....

The methods I'm familiar with involve reading the DOS area, but it seems that this will not work for you. Since it's a setting in *Windows* you need, maybe there is some kind of Registry value that you can read. Or possibly there is something in one of the INI files (win.ini or system.ini).

mjohnm

Thank you for the suggestion. I did indeed look through the registry but the information is stored in different places in different versions of Windows (eg XP vs 98). Seems messy to have to worry about what version of Windows I am using.

Anyway, I solved my problem using third party software. Check out TVicLPT or TVicHW32 which has additional functionality. The software is very reasonably priced, has worked well for me and does everything I need and then some! In particular it detects all LPT ports and their base addresses. ALso, it can direct IO port read and write. I recommend this software. (I have no relationship with the author other than being a customer.) There are other freeware software packages that can do what I need but I have not tried them.