Here is a list of the EPROM numbers fitted to the Smartstep, Denstep and Nextstep controller cards.
All the machines were supplied with DOS software before 2000 and a change over to the current VR Turning and VR Milling software in late 2000.
To identify what software will run on your controller you can simply check the version of the EPROM fitted to the control card.
If you have a DOS EPROM then you cannot use the latest VR Software without replacing the EPROM