Daveyh wrote:

The parallel port is a real port on a PCI card, not a USB dongle.

So far so good.

Is this Win7 x64? Are you using PortTalk or InpOut32?

my bad, it's XP SP3 32bit. The parallel port is the one on the motherboard (Dell tower, Xeon processor)

It's using the standard windows driver parport.sys. I did a standard windows install and then copied over the application from an old win98 PC. I had to change the port config to 'configuration6 IO 0378 to match the software. Added to the config file: parallel1=reallpt realbase:0378

I'm not familiar with PortTalk nor InpOut32 . Should I be using those?

Thanks!

Windows XP and later are much more restrictive than Windows 98 about what programs (including DOSBox and anything running within DOSBox) can do with the parallel port. PortTalk and InpOut32 are means of circumventing these restrictions.

It looks like the SVN Daum build actually includes InpOut32 at the moment. I reckon the problem you're having might have something to do with that, though I have no idea what it would be.

I suppose it would be a good idea to test an older version. I think you can use "Megabuild 6" (which is very old at this point) with PortTalk, especially since you're using 32-bit Windows. See the threads at Parallel port passthrough (Windows only) and Printing from DOSBox for starters.

Standard caveat: DOSBox is primarily intended for games and applications requiring parallel port passthrough are generally not supported.

I switched to Megabuild 6 which solved the issue of not being able to re-open the port. 😀 But I also use a second port that is a PCI port at address CCC8. It worked fine with SVN Daum but Megabuild 6 doesn't recognize it. Used the same settings in the config file.

Daum is broken and the Megabuild is very old. Also note that this forum is for official DOSBox. Take a look at vDos, which is intended for applications instead of games. http://www.vdos.info/

If your application needs direct hardware access to the parallel port, vDos won't work; Daum or Megabuild are probably the best solutions. But if you're only sending print data to LPT1 or LPT2, then vDos can be made to work. Until the new version of vDos is ready, vDos is downloadable from:

https://sourceforge.net/projects/vdos/

When the new version is ready, it will be at the link in collector's message (www.vdos.info). Right now, that link has some information, but no download.