Retrochallenge Update: Hacman Moves!


This is a delayed update, but I finally have first motion in my game.  I’ve been recreating a Pac-Man clone I first wrote as a high-school student for a text-mode terminal on our school’s PDP-11/60 running RSTS/E.

I’ll provide another update with more technical details, but this is great progress.  The only major parts of the game I need to finish are the ghost AI routines and the sprite collision routines;  the latter routines are almost trivial, so that leaves the AI.  This will either be doable—or not—and I am thinking it’s doable, so I expect that when the Retrochallenge ends for July,  I will have a working game!

In my game, presently, I can move the Hac-Man character.  It eats dots and pills, and the ghosts, while not moving, do change appearance, and change back.  Hac-Man can use the tunnel.  Points add up and the game logic correctly recognizes each level’s completeness.   I only need to add a fruit—my original game had two different fruits.  The levels top out at 255, in a homage to the original game (though it does not crash as the original game did.)

I deviated from history just a bit in the design of the maze:  The original game worked on a VT-52, and an ADDS terminal (the model number of which I do not remember and which is not on Bitsavers either).  Neither of them had line-drawing characters, only blocks (of a sort) that, as one commenter put it, made the game look more like the old Unix text classic Dungeon, rather than the casual maze of Pac-Man, and my clone.

Salem High just missed the VT-100 by that much, having gotten our system circa 1976;  the VT-100 was already available by the time I wrote my game in 1980.  I think its new appearance is worth any historical infidelity it may cause, since my program logic hasn’t changed any.    If there is still a PDP-11 running RSTS/E somewhere, it can run my game as long as it talks to a VT-100 or compatible.

Technical details will follow in my next post, and expect more frequent updates as I have more time to work on the game and explain even more of the details.

Wakka wakka wakka!


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s