The software itself is a classic example of DOS-based and early Windows engineering tools. It utilized a serial connection (RS-232) to communicate with the CPU. It was known for its "ladder logic" interface—a graphical programming language that resembles electrical relay logic diagrams.
If you have a GE Series 90-30 PLC sitting in a rack and you cannot find a working copy of LM90, what are your options? logic master lm90 software download zip 2021
Some GitHub users have uploaded "abandonware" industrial software for preservation. Search for lm90 or ge-fanuc-lm90 . Always check the license and readme files. The software itself is a classic example of