ARB GMS 3 und Sargon 3.5 sind emuliert, wieder dank an Berger =)
3.5 was provided as an upgrade to GMS 3 by Sandy Electronic. See:
https://www.schach-computer.info/wik...ARB_Sargon_3.5
I only did a hex compare of the files, but I believe they're completely different (not a minor bugfix update).
There are also no noticeable similarities between 3.5 and 4.0 when comparing the files.