Tobias let me know that he’s released his IDLEHLT16 driver for these early OS/2 versions. If anyone has run them in an emulator, you’ll know they’ll easily soak up 100% of the CPU they are given. This process will call the HLT opcode found in later (well compared to the 80286!) processors allowing them to ‘sleep’.
Needless to say, for fans of the beleaguered 16-bit OS, this is a great thing to have!
If anyone wants to know why there isn’t one for OS/2 2.0 and above, it doesn’t need one, it can sleep fine on it’s own.