Unlike Maxwell’s demon, Szilard’s demon does not require the result of a measurement in order to perform the appropriate action. This paper devises a simplified version of the original Szilad’s engine that permits a simpler analysis.
Landauer and Bennett (cited in the paper) concluded that there is an entropy increase in the erasure step required for a measurement. This paper claims to pinpoint the sub-step in which the entropy increase could occur.
Rolf Landauer did not like this paper at all, and we exchanged quite a few letters. I did not keep all of them, and I would have to read my paper carefully in order to understand what the discussion is about, but in case you are fond of archeology, I have scanned the correspondence and you can download it from here.