On Doom 1.0 (first shareware release to be precise), at times, it'll feel like there's run mode enabled....randomly, despite not holding down shift at all
Tested with 386 interpreter, 486 interpreter, 486 recompiler, Pentium recompiler, on AMI386 clone and AMI486 clone
Does not affect Doom 1.1, 1.2, 1.666, 1.8, 1.9
Alleviated if you rebind run (default rshift) to another key, like n, so something somewhere is triggering the shift key, which may or may not be related to the spectre vr dos bug
One notable difference between 1.0 and 1.1 is the slightly older DOS4GW (1.94a), may or may not be relevant
Doom v1.0 erratic player movement
Re: Doom v1.0 erratic player movement
Did you try using real hardware?