OK then Sherman, follow me into the wayback machine.
You didn't say which PLC you're trying to work with. It could be the Series One, Series Five, or Series Six. You also didn't say which version of Workmaster you have. Those pieces of information are necessary to identify the batch file that you need to run Logicmaster software. For example, when running Logicmaster 6 on the original Workmaster I computer, you'd need to run the file LM6WM.BAT
For Logicmaster 6 on a Workmaster II computer, the file is LM6PC.BAT
For a Series 1 PLC, it's L1FWM or L1FPC
If Logicmaster is already installed on the Workmaster's hard drive, then what you need to do is create a file called AUTOEXEC.BAT. DOS automatically looks for this file on boot, and executes the commands contained in it. Assuming that you want to run Logicmaster 6 on a Workmaster II computer, and that Logicmaster 6 has been installed to the subdirectory LM6, your AUTOEXEC.BAT file will need the following lines:
cd\LM6
LM6PC
It is also possible to run Logicmaster from floppies, but if you have a hard drive, I'd recommend running the software from it. It's much faster. If you feel you must run Logicmaster from floppies, then replace the 'cd\LM6' line with 'A:'. In that case you'll also need to modify the Workmaster's boot sequence to tell it NOT to look for a system disk in the A drive on boot.
Once you get the software running, I expect you'll be back with questions about connecting it to a PLC.
Please provide as much information as possible in future questions. I have a Workmaster II computer here, and a Series One and Series Six that I can connect it to, so I may be able to give you specific instructions to get you going.