To do this, you need any HEX Editor, I recommend WinHEX.
Chicago 1930: HEX-Cheat Codes [1.01] Free Download
1: Launch the HEX-Editor program.
2: Open with it a file from the game folder CHICAGO 1930.EXE.
3: We are looking for the desired offset, change it to the code we need and save the game file.
P.S – For those who do not know, the last digit or letter in the offset means a line in the code.
Immortality:
Offset: 00107A5C Code: 909090909090
Invisibility:
Offset: 0010B186 Code: 90909090909090
Eternal Ammo:
Offset: 00099C08 Code: E9A366F6FF90
Offset: 000002B0 Code: C682C8000000638B82C8000000E94C99
Offset: 000002C0 Code: 0900
Eternal slowdown:
Offset: 001A9099 Code: E92472E5FF90
Offset: 000002C2 Code: 66C781A80A0000DB058B91A80A00
Offset: 000002D0 Code: 00E9C98D1A00