Wednesday, 22 January 2014

Space Invaders ... completed.

The game is basically finished, coming in at exactly 1,000 bytes, slightly less than half the ROM space of the TMS1100.......

I'll update all the code and stuff after I've tested it a bit more, but it seems to basically work fine.

Space Invaders Session 4

It's now basically playable. The screen shows a game in progress.

You can shoot the invaders - they shoot back.

There's no end of level, or invaders landing test yet, and if you are hit the game just freezes.

But that's for another session, tidying up, displaying the score and lives, and so on.

Current code size is about 900 bytes of a 2k ROM, and just over 1000 lines of TMS1x00 assembler in four files. The current version (zipped) is downloadable from the links on the right, obviously it isn't finished yet.

I haven't tried it on the MESS emulator yet, I did try Bomber and that works fine. It should actually work better because MESS emulates the pixel latency properly, mine's a short cut.

In other, err.... news, Sean has decapped a BlockBuster and examined the PLA, confirming visually what we thought was the case anyway, that the PLA inverts the output on Vegas Slots (or to be more precise, every other game so far inverts the outputs !)

Space Invaders, session 3

Not Microvision Graphics btw.
I can now shoot the invaders, and keep score. Now need to get them shooting back - and tidy up - check for level over, landing, shot etc.