"0" will allow you to play without having to insert the CD!
CDCheckEnable - Toggles whether or not the game will check for the S&K Collection CD-ROM.NoSoundEffect - Toggles whether or not sound effects will be disabled.Screenshots are saved as "Cap(5-digit_number).bmp" in the game's directory. EnableFrameCapture - "1" allows you to take a screenshot of the game screen at any time by pressing F9.This will obstruct the game screen, but if debug mode is turned on then the game screen will be shifted down the window to allow the FPS counter to display without covering anything up. ShowFrameCount - Displays the FPS in-game when enabled.MukaiDropFrame - Basically functions in the reverse fashion of EnableFrameDrop.Set this to "1" and you can play in windowed mode at a perfectly playable speed.
However, the timings used by full screen mode are based on the monitor's refresh rate, so the game can be played at the correct speed at a 60 Hz refresh rate on any modern system.
However, you can properly enable it by creating a file named "S3K.ini" in your C:\WINDOWS directory (where C:\ is the main partition used for Windows) and typing the following into the file:
Though you can enter the debug menu code in-game, you cannot use any object placement functions as controls are limited to four directions and a single key for jumping. In Sonic & Knuckles, this method must be done on the pulley lifts in Mushroom Hill Zone. The method of unlocking the level select in Sonic 3 & Knuckles apparently works in Sonic 3 alone (a good thing, too, considering it's a lot easier to unlock this way) though debug mode won't be unlocked along with it and you can select any Sonic 3 zone as usual (but not Flying Battery, Mushroom Valley, Sandopolis, or Bonus). Press Alt + R to reset the game and from the title screen press Up to reveal "SOUND TEST" and press Enter. A ring sound will play if you did it right. Go to Angel Island 1, grab onto a swinging vine, and press Left, Left, Left, Right, Right, Right, Up, Up, Up.