Topic: Asteroids hardware

So I've taken Mike's excellent Asteroids code, actually it's Asteroids Deluxe and ported it to my own hardware driving a small vector monitor that I built using a VGA DAC to generate the X, Y and Z signals. I've modified the code and have the original Asteroids running, save for a few of the sound effects that I still need to model, IMHO the original is a superior game to Deluxe. Lunar Lander also uses extremely similar hardware, however I've hit a wall in my attempts to get that to run, the watchdog just keeps resetting it. I've examined it in Isim and it seems to behave logically at first, reading the program ROM, looping through a routine that initializes every location in the zero page RAM, then it starts reading from the vector ROM and writing to various locations in the vector RAM and then somewhere it ends up off in the weeds and resets. I've poured over the schematics and the code and can't find anything I've missed but maybe I've just been staring at it for too long.

Has anyone tried getting Lunar Lander running or would anyone like to take a crack at getting my code to work? While I'm not running on Replay hardware here, I'd be happy to backport any of my changes to the Asteroids core for the replay.

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Re: Asteroids hardware

Nice. I've got this pretty much ready to go on the Replay. The delay was in the rasterizer, I needed to add burst write capability to the memory controller.

StarWars is the one to get running smile

Re: Asteroids hardware

Star Wars would be awesome! Tempest is my personal favorite, and I like Quantum too. The latter has a powerful 68000 unlike any of the other Atari games of the era but I have not looked at how closely the rest of the architecture compares to the other games.

I've chopped off the rasterizer and used a VGA DAC to output X, Y and Z signals directly but as most people don't have a vector monitor laying around the rasterizer does make it more accessible. It could be handy for development too, it's easy to damage the deflection amplifiers if the game is misbehaving.

4 (edited by Gorf 2017-01-16 14:32:34)

Re: Asteroids hardware

I have a REAL cockpit Star Wars Arcade( I modded it to allow a switch out of roms to play Empire Strikes Back !) big_smile I would like to definitely see Star Wars and Empire Strikes Back run on the FPGA Replay board.... it would then justify me selling my arcade and being able to afford a Replay board. OF course I would like to see the Replay be able to handle the original controllers... all of which are digital so no A/D would be required. IT uses X,Y encoders for the steering yoke and should be a cinch for the Replay....using Grey's code I would imagine.

Re: Asteroids hardware

Awesome! Well, we'll have to add the vector driver to the Jamma board then, and get you to test it. Don't get rid of the cockpit yet.

Re: Asteroids hardware

Ditto!  I love the old vector games!

Re: Asteroids hardware

Star Wars does not use encoders, it uses ordinary pots in the flight yoke. I'm well familiar with that because I had to replace the pots in mine several times before I found some good ones that would hold up. There's no reason an FPGA implementation couldn't be made to work with encoders but that's not how the arcade cabinet worked.

The cockpits are awesome, especially with the 25" Amplifone monitor they originally came with. A friend of mine had one years ago that someone had stuck a 19" monitor in. We made a 25" using the yoke from a WG 19K6100 on a 25" TV tube and ran it all from an Amplifone deflection and HV board.

Re: Asteroids hardware

wow!
There are four analog inputs in the Replay board (direct into the ARM). How many pots are we looking at?

Re: Asteroids hardware

Just two, the flight yoke only has two axis.

There is some interesting info about it and the other Atari vector games on Jed Margolin's site.  http://www.jmargolin.com/vgens/vgens.htm

Re: Asteroids hardware

Yeah, I really enjoyed reading Jed's stuff. I had a really interesting email exchange with him as well which I seem to have lost now I look for it sad

Re: Asteroids hardware

I'd set this aside for a while but recently started playing with it again. Anyone interested in coding the missing sound effects from the original Asteroids? I tinkered with that for a while but was not happy with what I was able to get. Deluxe uses a POKEY, the original has additional analog circuits for the saucer sounds.

I still have no idea why Lunar Lander won't run either, everything looks fine in the HDL and simulating it things start out ok initializing the RAM and whatnot then the code runs off into the tumbleweeds and the watchdog trips. I suspect there's something stupidly simple that I'm overlooking.