I have run across a machine with an HMI per the picture below. It has a label with the following information on it.
2125-L
GL-OWS
QC/4LN/VF/64K/115VAC
C796280 0748.
Who makes it and what do you use to program it?
DosBox was originally made for the gaming industry, this was so they could run old games on newer PC's... I started using it in around 2005 for programming AB 100's and 150 running PCIS, 20 years later still using it and it works great
Private message me and I will send you a vmware virtual machine with dos and the gus software installed. You can use vmware player to run the virtual machine.