This is what I have done: 1. Download and install the D-Fend Reloaded in Portable mode onto an USB-disk (http://dfendreloaded.sourceforge.net/) 2. Download an extract the Megabuild 6 (http://home.arcor.de/h-a-l-9000/index.html) 3. Substitute the DOSBox folder installed onto the USB-disk with that …

Yippii! I tried your Megabuild 6, and it was a sucess 😀 Thanx again!

Thanx for your reply. Which SVN build would you recommend?

I run an old DOS-based PLC-programming tool in DOSBox 0.74. The programming tool seems to work well in the PC itself. But when I am trying to use the tool in order to communicate with an external PLC through the embedded COM-port, I get "communication error". Part of my dosbox.conf: [serial] serial1 …