Mauvila Posted September 4, 2007 Share Posted September 4, 2007 Hey folks, I maintain the JStella project at Sourceforge, but I must admit--I know next to nothing about homebrew games for 2600. So I was wondering whether anyone has an original (non-derivative) 2600 game that they will allow to be used as a demo for the JStella 2600 emulator applet? It would have to be completely legit for distribution. As I'm currently planning it, I will put a link on the SourceForge site to another site to display the Java applet (unless someone wants to set up the applet on their own site). (Sourceforge doesn't allow demo stuff on their servers). It would be nice if the game(s) was very Atari looking, appropriate for all ages, and of course, not in violation of any copyright laws. Thanks, JLA Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted September 4, 2007 Share Posted September 4, 2007 (edited) There are plenty of homebrews for download here at AtariAge. Go here and select Homebrew as rarity. All games with the Pac-Man symbol are for download. You got my permission for Thrust+, Jammed and SWOOPS! for anything that is not commercial or put on real carts. Edited September 4, 2007 by Thomas Jentzsch Quote Link to comment Share on other sites More sharing options...
Mauvila Posted September 4, 2007 Author Share Posted September 4, 2007 There are plenty of homebrews for download here at AtariAge. Go here and select Homebrew as rarity. All games with the Pac-Man symbol are for download. You got my permission for Thrust+, Jammed and SWOOPS! These happen to be the games (that I've run across) that don't yet work on JStella...they work on Stella though. I tried to get Thrust to work a couple of weeks ago, and I added support for another unofficial opcode, but then it came across the unrecognized opcode 0x2, which I don't know if this is another unofficial one or whether something got messed up in the CPU's IP or what...do you use the rla instruction, and is there such thing as 0x2? If yes to the former and no to the latter, then I probably botched the rla instruction... Thanks, JLA Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted September 4, 2007 Share Posted September 4, 2007 I tried to get Thrust to work a couple of weeks ago, and I added support for another unofficial opcode, but then it came across the unrecognized opcode 0x2, which I don't know if this is another unofficial one or whether something got messed up in the CPU's IP or what... do you use the rla instruction, and is there such thing as 0x2? If yes to the former and no to the latter, then I probably botched the rla instruction... 0x2 is no valid instruction. It causes the CPU to jam. But I don't use RLA. Those are the ones I use in Thrust+: $af ; illegal opcode for lax absolute $a7 ; illegal opcode for lax ZP $b3 ; illegal opcode for lax(),y $bf ; illegal opcode for lax,y $0c ; nop absolute Quote Link to comment Share on other sites More sharing options...
+batari Posted September 4, 2007 Share Posted September 4, 2007 I tried to get Thrust to work a couple of weeks ago, and I added support for another unofficial opcode, but then it came across the unrecognized opcode 0x2, which I don't know if this is another unofficial one or whether something got messed up in the CPU's IP or what... do you use the rla instruction, and is there such thing as 0x2? If yes to the former and no to the latter, then I probably botched the rla instruction... 0x2 is no valid instruction. It causes the CPU to jam. But I don't use RLA. Those are the ones I use in Thrust+: $af ; illegal opcode for lax absolute $a7 ; illegal opcode for lax ZP $b3 ; illegal opcode for lax(),y $bf ; illegal opcode for lax,y $0c ; nop absolute It seems that Thrust should work. I spent a few minutes trying to figure out what is so unusual about it, and the only thing that jumped out at me was the use of TIM1024, which I think very few games use. Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted September 4, 2007 Share Posted September 4, 2007 It seems that Thrust should work. I spent a few minutes trying to figure out what is so unusual about it, and the only thing that jumped out at me was the use of TIM1024, which I think very few games use. But it doesn't use TIM1024. Quote Link to comment Share on other sites More sharing options...
+batari Posted September 4, 2007 Share Posted September 4, 2007 It seems that Thrust should work. I spent a few minutes trying to figure out what is so unusual about it, and the only thing that jumped out at me was the use of TIM1024, which I think very few games use. But it doesn't use TIM1024. Found this in the last bank (thanks to Stella debugger): Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted September 4, 2007 Share Posted September 4, 2007 You are right. Quote Link to comment Share on other sites More sharing options...
Mauvila Posted September 4, 2007 Author Share Posted September 4, 2007 You are right. Fixed 'em all -- the culprit : a bug in the J6507 (CPU emulation), specifically with the stack pointer. Since Java doesn't use unsigned bytes, everything is in integers...had to add some things to mask out those extra bits. All 3 work now. Thanks, JLA Quote Link to comment Share on other sites More sharing options...
+atari2600land Posted September 4, 2007 Share Posted September 4, 2007 (edited) If you want to use GoSub, just PM me. Edited September 4, 2007 by atari2600land Quote Link to comment Share on other sites More sharing options...
supercat Posted September 5, 2007 Share Posted September 5, 2007 It seems that Thrust should work. I spent a few minutes trying to figure out what is so unusual about it, and the only thing that jumped out at me was the use of TIM1024, which I think very few games use. The TIM64T timer doesn't run long enough to time a whole frame. Especially during kernel development I like to set T1024T near the start of the frame (so it will expire in time for VSYNC) rather than setting TIM64T nearer the end of the frame. Doing the former means that adding or dropping lines in the kernel won't affect the frame rate. Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted September 5, 2007 Share Posted September 5, 2007 All 3 work now. Great! Quote Link to comment Share on other sites More sharing options...
+SpiceWare Posted September 5, 2007 Share Posted September 5, 2007 You're more than welcome to use Medieval Mayhem. The final NTSC ROM canbe found here. However, you may wish to use this ROM instead - I've set it to default to Player=1 and Flash=No. Quote Link to comment Share on other sites More sharing options...
Mauvila Posted September 6, 2007 Author Share Posted September 6, 2007 You're more than welcome to use Medieval Mayhem. The final NTSC ROM canbe found here. However, you may wish to use this ROM instead - I've set it to default to Player=1 and Flash=No. My reservation with MM is that the first impression it gives is Warlords, which might cause some bored corporate lawyer to send out a cease & desist... Quote Link to comment Share on other sites More sharing options...
Mauvila Posted September 6, 2007 Author Share Posted September 6, 2007 There are plenty of homebrews for download here at AtariAge. Go here and select Homebrew as rarity. All games with the Pac-Man symbol are for download. You got my permission for Thrust+, Jammed and SWOOPS! for anything that is not commercial or put on real carts. Thrust might be good to use-it's got the space-ship feel of Atari games... but unfortunately, there is still a bug somewhere...the game automatically starts upon loading, without the start screen. Also, the graphics look a little too good, better than those that most people remember about the 2600... Quote Link to comment Share on other sites More sharing options...
Steril707 Posted September 6, 2007 Share Posted September 6, 2007 Also, the graphics look a little too good, better than those that most people remember about the 2600... that's true..shame on you, Thomas... Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted September 6, 2007 Share Posted September 6, 2007 that's true..shame on you, Thomas... Sorry. Quote Link to comment Share on other sites More sharing options...
+SpiceWare Posted September 6, 2007 Share Posted September 6, 2007 (edited) My reservation with MM is that the first impression it gives is Warlords, which might cause some bored corporate lawyer to send out a cease & desist... I wouldn't expect a problem - if I remember correctly, somebody at Atari told Al that he was impressed with the graphics. Al could probably clarify that when he returns from his vacation. As an alternative, you could have a list of "JStella in action" and include links to AtariTimes.com, SpiceWare.org and AtariAge.com whenever Al gets around to adding JStella to the store front. Edited September 6, 2007 by SpiceWare Quote Link to comment Share on other sites More sharing options...
mos6507 Posted September 6, 2007 Share Posted September 6, 2007 You're more than welcome to use Medieval Mayhem. The final NTSC ROM canbe found here. However, you may wish to use this ROM instead - I've set it to default to Player=1 and Flash=No. My reservation with MM is that the first impression it gives is Warlords, which might cause some bored corporate lawyer to send out a cease & desist... And Thrust of Gravitar? Quote Link to comment Share on other sites More sharing options...
Mauvila Posted September 6, 2007 Author Share Posted September 6, 2007 You're more than welcome to use Medieval Mayhem. The final NTSC ROM canbe found here. However, you may wish to use this ROM instead - I've set it to default to Player=1 and Flash=No. My reservation with MM is that the first impression it gives is Warlords, which might cause some bored corporate lawyer to send out a cease & desist... And Thrust of Gravitar? As far as a Rorschach impression goes, Gravitar (2600) didn't immediately pop into my head... although I'm wondering if Atari's current incarnation still owns the copyright to Warlords etc, or did they buy just the name and logo? Quote Link to comment Share on other sites More sharing options...
Mauvila Posted September 6, 2007 Author Share Posted September 6, 2007 My reservation with MM is that the first impression it gives is Warlords, which might cause some bored corporate lawyer to send out a cease & desist... I wouldn't expect a problem - if I remember correctly, somebody at Atari told Al that he was impressed with the graphics. Al could probably clarify that when he returns from his vacation. As an alternative, you could have a list of "JStella in action" and include links to AtariTimes.com, SpiceWare.org and AtariAge.com whenever Al gets around to adding JStella to the store front. I think it would be great to link to other sites, but I would want explicit permission from the website owner...I don't know what type of traffic/scrutiny a SourceForge link would bring... Do I take it you consent to the Spiceware JStella page being targeted by a link? Thanks JLA Quote Link to comment Share on other sites More sharing options...
+SpiceWare Posted September 7, 2007 Share Posted September 7, 2007 (edited) And Thrust of Gravitar? Actually, Thrust looks a lot like Thrust Edited September 7, 2007 by SpiceWare Quote Link to comment Share on other sites More sharing options...
+SpiceWare Posted September 7, 2007 Share Posted September 7, 2007 although I'm wondering if Atari's current incarnation still owns the copyright to Warlords etc, or did they buy just the name and logo? I don't know. I think it would be great to link to other sites, but I would want explicit permission from the website owner...I don't know what type of traffic/scrutiny a SourceForge link would bring...Do I take it you consent to the Spiceware JStella page being targeted by a link? Yep, that would be A-OK with me. Quote Link to comment Share on other sites More sharing options...
Mauvila Posted September 13, 2007 Author Share Posted September 13, 2007 Put up a few links to JStella applets running homebrews, including Spiceware. The current version for some reason isn't running thrust as it should...it doesn't hold when it gets to the opening screen...it flies right into the game. Does anyone know why it might be doing this? Or what is different about thrust versus other games as far as this opening screen goes. To see the behavior, you can check out the applet online at this address. Quote Link to comment Share on other sites More sharing options...
+SpiceWare Posted September 13, 2007 Share Posted September 13, 2007 (edited) Thrust supports the CBS Booster Grip, which adds 2 extra buttons that are wired to the paddle inputs. Thrust uses the extra buttons as Fire and Thrust. I bet the paddle readings are coming across if those buttons were pressed. There's also http://www.ataritimes.com/jstella Also the Atari's pixels are fat compared to other systems. The applet width x height should normally be set to 320 x 192 or 640 x 384 instead of 480 x 480. Edited September 13, 2007 by SpiceWare Quote Link to comment Share on other sites More sharing options...
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