DOS32A (DOS/32 Advanced DOS Extender) is a free and open source software that can be used to replace the DOS4GW.EXE DOS Extender file that many DOS games use.
Once a game uses this (although see note), it is expected to run faster and better in DOSBox.
Some games do not work with DOS32A at all. For example, Shadowcaster is incompatible with it because RAVEN.EXE run with DOS32A is unable to find the A32SBDG.DLL file that is in the same directory, while with DOS4GW it can.
- If a game uses DOS4GW.EXE, be sure to try using DOS32A instead, but always back up the original file first.