Return to Fort Knox

(aka Raid on Fort Knox II - the revenge)

Enjoy this updated version of a classic Commodore cartdrige game!

Our little blue man is back to Fort Knox greedly looking for more and more gold bars. But this time there are more black panthers to guard the corridors, and sacking the bank is almost impossible. Help the little man predate all the new eight Fort Knox mazes. Use his new ice-ray pistol to freeze the guards making them unable to move (C= key or fire on the joystick).

A little of history.....

Raid on Fort Knox was the first video game I played on my newly bought VIC-20, back in 1984 (I was 12). At the time I hadn't a tape recorder to play games, so a friend borrowed me his cartdrige. I didn't even had a joystick, so I played using the keyboard (I was happy the game had that feature). I remember lot of playing with my older brother and my friends who came and see me to play with the VIC-20. It lasted shortly until I had to give back the cartdrige, but nonetheless the game left in me an indelible memory of those days.

Twenty-three years later, during a rainy friday afternoon, I felt compelled to disassemble to 8K-ROM file of the cartdrige game. It took me an entire weekend. On the Denial forum I wrote about it:

"I did it for the fun of it, and indeed it was a rewarding experience. At first, everything was obscure and meaningless, I didn't even know what was code and what was data, but at the end of the process every single byte was assigned to a purpose. It was challenging, I had to "enter" the head of the original programmer and see thru his eyes. So I labeled and commented the whole code, giving it a second life! I wonder if the original source code is lost or is in the hands of the original developer or perhaps in the hands of what remains of Commodore ltd".

After disassembling it, I started to optimize the code and eventually it forked into this remixed version that I called Return to Fort Knox (or Raid On Fort Knox 2 if you prefer). I increased the number of guards upto 15, added the "freezing ray", and designed a new set of eight levels. Drawing the mazes was the hardest part because of the special movement of the guards: they turn left or right when meet an obstacle, but never turn back. So I had to pay attention that every part of the maze was reached by the guards in a balanced manner, otherwise the level would have resulted too easy or too hard. The drawing thing took so long that months later I was about to give up (thanks to Nbla000 for the moral support!).

Some info about the game....

Raid On Fort Knox amazes for its smooth scrolling moving "sprites" which is unusual among VIC-20 games. That feature is achieved by having "sprites" precalculated and already put in the definable character area. This way there's no need to calculate them at run time. There are two shapes: the "man" and the "guard", each one spanning on two characters when they move, and they can have four different motions (cardinal directions). Each of these has eight different "shift" positions for smooth movement, so in total: 2 x 2 x 4 x 8 = 128 characters that eat up most of VIC 20's unexpanded memory (that's why the game needs 8K expansion).

Commodore released "Raid On Fort Knox" in 1982 but an early (and slightly different) version of the game was already marketed in 1981 as "Bank Robber".

And now the download!

Here you can download the whole Return To Fort Knox pack archive containing:

Return To Fort Knox.prg

Game executable for the 8K or 16K expanded VIC-20

additional material:
raid2.lm, chars.lm, macros.lm, maze0.lm Game assembler sources
Raid On Fort Knox.prg Original Commodore game, ROM cartdrige image
raid.lm Original Commodore game assembler sources
Raid On Fort Knox 8K.prg A relocated version of the original game for 8K/16K expansion
Bank Robber.prg The 1981 version called "bank robber", original ROM cartdrige image

Return to Fort Knox is also featured on the Brian Lyons MEGACART !



© 1998-2008 Nino Porcino