Copy ProtectionThe 688 Attack Sub box stated that the game was NOT copy protected. However, in order to start a mission you had to transmit a code to fleet command which consisted of looking up a sub name in the manual and finding the corresponding code. The codes were scattered all through the manual making pirating difficult.
ExtrasThe first edition release came with a nice 688 Hunter / Killer patch underneath the outer shrinkwrap.
GameplayYou could play for either the American or Soviet navy. Different graphics were used for the subs on each side with Soviet text optionally appearing in a Cyrillic font (but still in English).
InstallationThe first time you install the game, it asked you for your first name. Your name was then saved onto the game disk so all future installs would use this name. There was no option to change it.
Additional information contributed by gametrader