HexCheat:

 First use UNP.EXE to decompress D.EXE. Now load D.EXE into the
 Hex editor and

 search for        66 29 06 64 D5
 and change it to  90 90 90 90 90

 for unlimited energy.

 Search for        66 29 06 5C D5
 and change it to  90 90 90 90 90

 for unlimited shields.

 Search for        66 81 2E 64 D5 FA 00
 and change it to  66 81 2E 64 D5 00 00

 for full phaser energy.