42bs Posted February 28, 2023 Share Posted February 28, 2023 After a hint from @CyranoJ I made a super fast bootloader. https://github.com/42Bastian/new_bjl/tree/main/fastboot 8 Quote Link to comment Share on other sites More sharing options...
Cyprian Posted March 1, 2023 Share Posted March 1, 2023 Is it somehow connected with https://github.com/42Bastian/new_bjl/tree/main/fastboot? Quote Link to comment Share on other sites More sharing options...
42bs Posted March 1, 2023 Author Share Posted March 1, 2023 27 minutes ago, Cyprian said: Is it somehow connected with https://github.com/42Bastian/new_bjl/tree/main/fastboot? Not sure what you mean, it is the same link?! Quote Link to comment Share on other sites More sharing options...
Cyprian Posted March 1, 2023 Share Posted March 1, 2023 I mean the process of a fastboot, is it similar or no. Anyway, can you please explain how your fast boot works? Quote Link to comment Share on other sites More sharing options...
42bs Posted March 1, 2023 Author Share Posted March 1, 2023 1st it skips the logo screen by setting the diagnosis flag, then it copies the code added behind into RAM, sets the $3d0dead flag to notify that everything is ok and stops the GPU. The BIOS then jumps to the copied 68k code. The.BIOS decrypts the header in chunks of 64 bytes. So the loader is trimmed to use only a single chunk. A different version is in jagniccc2000_reloaded, there I directly stop the 68k from GPU and copy the main GPU code to RAM and continue there. A third version (posted on discord) is even simpler and directs the code to $80040c. 4 Quote Link to comment Share on other sites More sharing options...
42bs Posted March 1, 2023 Author Share Posted March 1, 2023 Just place the code linked for $80040c behind this header. fastboot.XXX 3 Quote Link to comment Share on other sites More sharing options...
Cyprian Posted March 1, 2023 Share Posted March 1, 2023 thanks Quote Link to comment Share on other sites More sharing options...
Tursi Posted March 4, 2023 Share Posted March 4, 2023 On 3/1/2023 at 1:11 PM, 42bs said: 1st it skips the logo screen by setting the diagnosis flag, then it copies the code added behind into RAM, sets the $3d0dead flag to notify that everything is ok and stops the GPU. The BIOS then jumps to the copied 68k code. The.BIOS decrypts the header in chunks of 64 bytes. So the loader is trimmed to use only a single chunk. A different version is in jagniccc2000_reloaded, there I directly stop the 68k from GPU and copy the main GPU code to RAM and continue there. A third version (posted on discord) is even simpler and directs the code to $80040c. If you're only using a single chunk, then I don't think it will work with the JagCD plugged in - did you try that? You can check my notes here, but I'm curious if you got around that https://github.com/tursilion/makefastboot http://tursilion.blogspot.com/2016/09/atari-jaguar-programming-causes-brain.html 2 Quote Link to comment Share on other sites More sharing options...
42bs Posted March 5, 2023 Author Share Posted March 5, 2023 Hi, no it won't. As you write, the CD ROM decrypts two chunks and enters at a different address. But then, careing about three or was it four JagCD owners? (I am one, but it is buried under a pile of Atari ST,TT and STe, some Apple II, Quadra etc). But I may take the challenge 🙂 1 1 Quote Link to comment Share on other sites More sharing options...
+cubanismo Posted March 6, 2023 Share Posted March 6, 2023 (edited) Uhg. Hope this doesn't get used in distributed ROMs then. I'm 1/4, 2/4, and 3/4 of those JagCD uses, and it's a pain to detach them. Edited March 6, 2023 by cubanismo still, cool code. Quote Link to comment Share on other sites More sharing options...
42bs Posted March 6, 2023 Author Share Posted March 6, 2023 8 minutes ago, cubanismo said: Uhg. Hope this doesn't get used in distributed ROMs then. I'm 1/4, 2/4, and 3/4 of those JagCD uses, and it's a pain to detach them. Oh. I detached mine some 20yrs ago. I think CJ likes to add it to JS. So I need to investigate. Unfortunately BPE does not allow to have "CD ROM" unit attached and boot a card. So it means, I really need to find my CD unit in the pile ... Quote Link to comment Share on other sites More sharing options...
Cyprian Posted March 6, 2023 Share Posted March 6, 2023 (edited) On 3/1/2023 at 7:28 PM, 42bs said: Not sure what you mean, it is the same link?! ugh, I just realized that I pasted the wrong link, it should be that @Tursi one: https://github.com/tursilion/makefastboot 😬 Edited March 6, 2023 by Cyprian Quote Link to comment Share on other sites More sharing options...
42bs Posted March 6, 2023 Author Share Posted March 6, 2023 Hmm, does JagGD work with Jaguar CD? I dag out mine CD. Games work, Skunk works but JagGD only shows the title screen?! Quote Link to comment Share on other sites More sharing options...
42bs Posted March 6, 2023 Author Share Posted March 6, 2023 😞 FAQ says, it does not work. Hope there is/will be a work around. Quote Link to comment Share on other sites More sharing options...
+cubanismo Posted March 6, 2023 Share Posted March 6, 2023 Yeah, the 4th Jaguar I use regularly doesn't have a JagCD. It has a GameDrive that I occasionally use to emulate a JagCD 😁 First world problems abound over here. Quote Link to comment Share on other sites More sharing options...
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