norbert_kehrer Posted February 23, 2013 Share Posted February 23, 2013 After my version for the Atari 800XL, I now made also an Asteroids emulator for the Commodore 64. The original program of the Atari arcade machine, which is 6502 based, is directly executed by the C64's 6510 CPU. The graphics and sound hardware of the original machine is (more or less) exactly simulated by the C64 in software. The main challenge was (and a little bit still is) to accomplish an acceptable and constant speed. If you are interested, you can visit my homepage for a description, screenshots, a video, and the download of the PRG file: http://web.utanet.at/nkehrer/ Have fun! Norbert 7 Quote Link to comment Share on other sites More sharing options...
desiv Posted February 23, 2013 Share Posted February 23, 2013 Nice.. Is it just me? I'm not hearing sound on your vid of the emulator on the Atari 800 version, but I am on the C64 version? Anyway, nice job!! Looks very impressive!!! I would have bought that back in the day easily!!! desiv Quote Link to comment Share on other sites More sharing options...
Kurt_Woloch Posted February 23, 2013 Share Posted February 23, 2013 Nice job... but as you said, there are speed problems. Are you drawing all those asteroids as lines? Maybe the speed would be better if you'd intercept the drawing routines earlier and draw the asteroids as sprites or soft sprites. I know the C-64 only has 8 sprites, and that's not enough to draw all the sprites that can possibly be on screen. So maybe it would be the best thing to draw the biggest objects using sprites and using soft sprites for the smaller objects. Another technique would be to multiplex the sprites like Darrel Spice, Jr. has done in "Space Rocks" for the Atari 2600. Quote Link to comment Share on other sites More sharing options...
The Usotsuki Posted February 23, 2013 Share Posted February 23, 2013 I wonder how hard it would be to do something like this on the Apple ][... Quote Link to comment Share on other sites More sharing options...
Keatah Posted February 24, 2013 Share Posted February 24, 2013 Natively written asteroids? Very nice. There's some clones which look good as it is. Emulation asteroids? Probably pretty difficult. You have no custom chips to help out. What about sound? Sound is too CPU intensive. But good luck to anyone that gives it a go. Quote Link to comment Share on other sites More sharing options...
The Usotsuki Posted February 24, 2013 Share Posted February 24, 2013 There's always the Mockingboard. xD Quote Link to comment Share on other sites More sharing options...
JamesD Posted February 24, 2013 Share Posted February 24, 2013 There's always the Mockingboard. xD Where have I heard that before? Quote Link to comment Share on other sites More sharing options...
norbert_kehrer Posted February 24, 2013 Author Share Posted February 24, 2013 Nice.. Is it just me? I'm not hearing sound on your vid of the emulator on the Atari 800 version, but I am on the C64 version? Thanks to all posters for the nice feedback. The video for the Atari 800 version lacks sound (due to a problem with my Altirra installation I suppose), but the actual emulator supports sound also on the Atari 800. Norbert Quote Link to comment Share on other sites More sharing options...
Keatah Posted February 24, 2013 Share Posted February 24, 2013 (edited) Imagine having this back-in-the-day! Very nicely done. Soon enough we'll be playing MAME on the VIC-20. And running Windows on the Timex-Sinclair 1000. Edited February 24, 2013 by Keatah Quote Link to comment Share on other sites More sharing options...
+save2600 Posted February 24, 2013 Share Posted February 24, 2013 (edited) Love it! Awesome job... are you still working on optimizing for speed or is this it for the C64 you think? Edited February 24, 2013 by save2600 Quote Link to comment Share on other sites More sharing options...
JamesD Posted February 24, 2013 Share Posted February 24, 2013 It's sad that the original arcade source code was never shared with licensees back in the day or we could have seen lots of arcade accurate games like this. Quote Link to comment Share on other sites More sharing options...
Hatta Posted February 24, 2013 Share Posted February 24, 2013 Have you considered a port to the C128? The extra speed makes a huge difference for the C128 port of Elite, I bet you could make good use of it too. Quote Link to comment Share on other sites More sharing options...
amiman99 Posted February 25, 2013 Share Posted February 25, 2013 I'll try the C64 version tonight, btw, the Atari 800 version runs nice on real 130XE. Quote Link to comment Share on other sites More sharing options...
norbert_kehrer Posted February 26, 2013 Author Share Posted February 26, 2013 Love it! Awesome job... are you still working on optimizing for speed or is this it for the C64 you think? Thanks to all for the feedback. I put a version with improved sound and a little speedup online yesterday on my homepage, and I will now try to further improve the speed on the C64. Norbert 1 Quote Link to comment Share on other sites More sharing options...
amiman99 Posted February 28, 2013 Share Posted February 28, 2013 I played the game on real C64C, works great! A bit slow, but great. Nice job, how about porting Tempest to A800 or C64? It runs on same processor 6502 running at 1.5mhz and the ROM size is 20k. Quote Link to comment Share on other sites More sharing options...
norbert_kehrer Posted March 6, 2013 Author Share Posted March 6, 2013 (edited) Have you considered a port to the C128? The extra speed makes a huge difference for the C128 port of Elite, I bet you could make good use of it too. Thanks for your proposal, Hatta. I made an update of the Asteroids Emulator. The program now checks, if it is running on a C128 in C64 mode, and in that case it switches to the 2 MHz clock frequency, when the raster beam is in the border. This method allows a speedup of approximately 30% compared to the genuine C64 and results in smoother movements in the game. Those, who are interested, can download the new version from http://web.utanet.at/nkehrer/ Best regards Norbert Edited March 6, 2013 by norbert_kehrer 1 Quote Link to comment Share on other sites More sharing options...
Keatah Posted March 7, 2013 Share Posted March 7, 2013 (edited) never mind.. Edited March 7, 2013 by Keatah Quote Link to comment Share on other sites More sharing options...
+JAC! Posted May 10, 2013 Share Posted May 10, 2013 Hi Norbert, just found this by incident when I saw this and have to say I'm impressed. Amazing multi-platform effort! Quote Link to comment Share on other sites More sharing options...
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