Jonas Hirvonen produced the All Seeing Eye, an automapping and general utility for Eye of the Beholder 1 & 2. Currently it won't work for EoB III.
It can be found at:http://personal.inet.fi/koti/jhirvonen/ase/
This page shows the ASE in action.
Needs a refresh function, currently once something is mapped, it stays mapped.
One approach is to make a backup copy of each Explored_##.dat file whenever you save the game. Then when you need to load, you shut down ASE and replace the relevant Explored_##.dat files with the backup copies. These files are found in the EOB1 or EOB2 folder (of ASE) as the case may be.
Deleting the Explored_##.dat file will get rid of the map for that level altogether. If you initially explore a new level after the last save is made, if you reload you will need to get rid of the map for the new level.
Saving, there may be up to six EOBData#.sav save game files at once. ASE can detect which was the last one saved. You would want one folder for each set of Explored_##.dat files.
Loading, a menu will appear and the default choice will be the last game that was saved.
Needs ability to add finishing touches, walls where the party could not reach. There is an Explore Level function which explores the whole level, but it is excessive when you only want to tidy a few loose walls.
(Post edited to improve clarity.)