Update: I've got a period (mid-1990s) PC running Windows 3.1 on top of MS-DOS 6.22. I installed the DOS and Windows 3.1 versions of Lego Control Lab 1.3. But there are two problems:
1. Both versions boot to an error message saying it doesn't see the hardware box. The PC has a real serial port which, AFAIK, works properly. I've got a null-modem cable connecting it to the 9751 interface box which is powered on.
2. I can't figure out how to access the menus! The usual "alt" and "ctrl" keys do not get me to the top menus. In the Windows version, the mouse doesn't operate in the Lego window; the cursor doesn't even appear there. No clue why or how to proceed! In the 1980s version of TC Logo (on my Apple II), you press something like ctrl-U (for 'up') and ctrl-D to go up/down between the main menu and the console. That also didn't work here in the DOS/Windows versions. So, again, I have no idea how to proceed! Does anyone know?
3. I will see if this machine's old HDD has enough space for Windows 95 and then try that version of the Lego software. But the Windows 3.1 version is the one I care about.