Eckhard Stolberg Posted August 29, 2005 Share Posted August 29, 2005 Accesses to $1FF8 are harmless until the first access to the range $1000-$10FF. I believe accesses to $1FF9 are harmless, but won't return correct data; not sure about that one, though. Accesses to $1FF8 will always change the state of the SC to whatever value was in the write buffer last. If $1000-$10FF wouldn't get accessed at all, that would be the initial value of the write buffer. But since the SC BIOS needs to access the 'load trigger' addresses during the loading process of the game, the value in the write buffer at the start of your game will depend on which byte was read from tape last. You are correct about $1FF9 though. That byte only returns the audio input in bit 7. Accessing it doesn't change anything in the SC config. I wonder if there's any technical reason Arcadia/Starpath couldn't have used $0800-$08FF as the 'load trigger' hot-spot and e.g. $0FFF as the bank-switch hotspot? 920517[/snapback] I don't think there are any technical reasons for Starpath's choice of trigger addresses. They probably just were carefull when chosing only addresses in the cart's address space, since they had to reverse engineer the inner workings of the VCS and didn't know exactly what all those unused addresses in the lower half of the VCS's address space were doing. Ciao, Eckhard Stolberg Quote Link to comment Share on other sites More sharing options...
supercat Posted August 29, 2005 Share Posted August 29, 2005 Accesses to $1FF8 will always change the state of the SC to whatever value was in the write buffer last. Wouldn't the last thing in the write buffer be the value that the BIOS loaded into $1FF8 just before starting user code execution? I don't think there are any technical reasons for Starpath's choice of trigger addresses. They probably just were carefull when chosing only addresses in the cart's address space, since they had to reverse engineer the inner workings of the VCS and didn't know exactly what all those unused addresses in the lower half of the VCS's address space were doing. Well, they probably didn't think about the fact that even though there are no addresses that can usefully return any data below $1000, there are lots of addresses which don't do anything notable when read. A continuity tester would pretty well show how address mirroring had to work (given that many address wires don't connect to the TIA or RIOT). Quote Link to comment Share on other sites More sharing options...
Eckhard Stolberg Posted August 29, 2005 Share Posted August 29, 2005 Wouldn't the last thing in the write buffer be the value that the BIOS loaded into $1FF8 just before starting user code execution? 920927[/snapback] Yes, you are right. The last thing the BIOS does is to place the control byte value in the write buffer and then jump to some code in RIOT RAM that accesses $1FF8 and then jumps to the game's start address from the header. So accessing $1FF8 indeed is harmless if your game hasn't accessed $1000-$10FF at all before. But like $1FF9 you probably wouldn't get the proper byte back from a read of $1FF8. Ciao, Eckhard Stolberg Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted August 30, 2005 Author Share Posted August 30, 2005 Interesting. And now solve the occasional screen rolling problem in Splatform. Quote Link to comment Share on other sites More sharing options...
DEBRO Posted August 30, 2005 Share Posted August 30, 2005 Interesting. And now solve the occasional screen rolling problem in Splatform. Did you not get my last e-mail yesterday? Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted August 30, 2005 Author Share Posted August 30, 2005 Did you not get my last e-mail yesterday? The VBLANK related one? Yup, got it! Any further results from your experiments? Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted September 20, 2005 Author Share Posted September 20, 2005 Dennis found the problem and with a little help from [stella] I was able to fix it. Thanks to Dennis for testing the result. Anyway, here is the result. If you don't find any further bugs, this is going to be the final one. Swoops_.zip Quote Link to comment Share on other sites More sharing options...
vdub_bobby Posted September 20, 2005 Share Posted September 20, 2005 Stella Pro entry: "Cartridge.MD5" "278f14887d601b5e5b620f1870bc09f6" "Cartridge.Name" "Swoops! (v0.96) (Thomas Jentzsch)" "Cartridge.Note" "Uses the Joystick (L) and Paddle (R) Controllers" "Controller.Left" "Joystick" "Controller.Right" "Paddles" "Display.Format" "NTSC" "Display.YStart" "28" "" Quote Link to comment Share on other sites More sharing options...
Albert Posted September 20, 2005 Share Posted September 20, 2005 Stella Pro entry: "Cartridge.MD5" "278f14887d601b5e5b620f1870bc09f6" "Cartridge.Name" "Swoops! (v0.96) (Thomas Jentzsch)" "Cartridge.Note" "Uses the Joystick (L) and Paddle (R) Controllers" "Controller.Left" "Joystick" "Controller.Right" "Paddles" "Display.Format" "NTSC" "Display.YStart" "28" "" 935064[/snapback] That's handy, thanks! I need to try this with two Stelladaptors, one with a joystick plugged in and the other with a pair of paddles.. ..Al Quote Link to comment Share on other sites More sharing options...
Emehr Posted September 22, 2005 Share Posted September 22, 2005 Tested the latest build with my unmodified Supercharger and 4-switch woody. The death scene rolling in Splatform has been fixed! Steady as a rock. Unfortunately, when I go to hit select to change games, everything goes haywire: garbage video and low buzzing. This only happens when hitting Select during Splatform, by the way. - Jason Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted September 22, 2005 Author Share Posted September 22, 2005 Unfortunately, when I go to hit select to change games, everything goes haywire: garbage video and low buzzing. This only happens when hitting Select during Splatform, by the way. That's "intentional", the game is not meant to work on unmodifyied SCs. Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted October 28, 2005 Author Share Posted October 28, 2005 Time to unstick this topic. Thanks! Quote Link to comment Share on other sites More sharing options...
carpecarne Posted October 28, 2005 Share Posted October 28, 2005 Oh yay! Is there a cartridge coming out soon! Oh boy oh boy! Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted October 28, 2005 Author Share Posted October 28, 2005 Oh yay! Is there a cartridge coming out soon! Oh boy oh boy! 955841[/snapback] Yup! And I am sure, Albert can post an impressive picture soon. Quote Link to comment Share on other sites More sharing options...
Albert Posted October 28, 2005 Share Posted October 28, 2005 Oh yay! Is there a cartridge coming out soon! Oh boy oh boy! 955841[/snapback] Yup! And I am sure, Albert can post an impressive picture soon. 955898[/snapback] I posted this to another thread already, but I don't think many people get down to the Events forum. So here's a picture I took yesterday of a completed Swoops! cartridge: Dave Exton did a fantastic job, as always. ..Al Quote Link to comment Share on other sites More sharing options...
carpecarne Posted October 28, 2005 Share Posted October 28, 2005 (edited) Hey Thomas, I'm playing the Swoops version of Splatform and it seems to be different from the version I'm used to which is v1.01. In my opinion, the latter version has less bugs in it. For instance, there are no (VBLANK?) lines on the far left and when you go off screen at the end of a level, the little face doesn't reappear on the other side. In anycase it's a great game, I was just wondering why these choices were made (code optimization perhaps?) PS: I'm using the Swoops ROM from this thread and I'm using Stella 2.01 on a mac. Edited October 28, 2005 by carpecarne Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted October 28, 2005 Author Share Posted October 28, 2005 PS: I'm using the Swoops ROM from this thread and I'm using Stella 2.01 on a mac. Don't worry too much, this is just an emulator bug. On real hardware (or with z26), there are no VBLANK lines visible on the left and Toto also does not reappear there. It is a bug with positioning the ball which should blank the left 8 pixels. The Stella guys are working on fixing it... Quote Link to comment Share on other sites More sharing options...
carpecarne Posted October 28, 2005 Share Posted October 28, 2005 Oh ok, I remember you talking about that. I just found it weird how differently it behaved with 2 similar ROMs. Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted October 28, 2005 Author Share Posted October 28, 2005 Oh ok, I remember you talking about that. I just found it weird how differently it behaved with 2 similar ROMs. 956036[/snapback] I had to do some code modifications to fit in the menu and make the three games work together. Quote Link to comment Share on other sites More sharing options...
davepesc Posted November 10, 2005 Share Posted November 10, 2005 Can anyone post a few screenshots? I think I want to pick this up at VGXPO, but I would like to see what it looks like. Thanks! Quote Link to comment Share on other sites More sharing options...
+Nathan Strum Posted November 10, 2005 Share Posted November 10, 2005 http://www.atariage.com/features/shows/vgp.../new_games.html Quote Link to comment Share on other sites More sharing options...
davepesc Posted November 10, 2005 Share Posted November 10, 2005 Looks great, as does the minigame multicart. RPS might be the best label ever, but I don't think I'd get much play out of that one. Quote Link to comment Share on other sites More sharing options...
+Nathan Strum Posted November 10, 2005 Share Posted November 10, 2005 RPS might be the best label ever, but I don't think I'd get much play out of that one. Then buy it for the label. (and thanks for the compliment!) Quote Link to comment Share on other sites More sharing options...
Room 34 Posted November 10, 2005 Share Posted November 10, 2005 (edited) Just downloaded this... these games are great! Very nice work. Cave is fun and challenging, and very well done. Splatform reminds me of a certain part of Super Mario Bros. 3. Another one that's really well-done. I haven't tried Crash 'n Dive yet, because I'm terrible at controlling paddle games with the mouse (or even worse, the trackpad, which is my present situation), but I'm sure it's great too. I just wish I had a way to play this on a real 2600! Edited November 10, 2005 by Room 34 Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted November 11, 2005 Author Share Posted November 11, 2005 I just wish I had a way to play this on a real 2600! Carts are available in the store right after vgXpo. Quote Link to comment Share on other sites More sharing options...
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