Source code is unavailable, but the executable contains several class
names, which can be seen starting at 0xDD91A
.
C3134583482E92B3F26E1FA44D8114DC91441A2F (Petz II.EXE)
Using a Windows resource viewer, one can find Window 110.
It seems like a serial number generator was used by the devs at
one point, as one can be found in the executable as Window 181.