Techie Thing
You can use this in conjunction with the Alt-= cheat below
ctrl-alt-rshift-f12 to find your current coordinates

Customer Cheat
B-I-G for health and jetpack power

Codes
The following work in v1.1 of Harry only
CTRL-R-E-N activates all weapons, activates god mode for less than 1 minute. This mode gets disabled at the end of each level. This mode must be active to use other modes.

ALT-L beep will sound and display will freeze, type 11, 12, 13, 14, or 15 to warp to respective level 1.1, 1.2, 1.3, 1.4, 1.5
typing wrong level numbers will dump program to DOS.

ALT-= (type coordinates to change location)
Start the game with the command line password 'skip' (ie; hh1 skip) and the game will start directly at the main menu.