Thursday, 30 August 2018 03:08

Return to active development

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After a long hiatus (over 3 years!), I'm finally returning to give this project some love. At the end of the day, this is just a hobby, and it has to move aside when real life issues require more of my time. Although I can't promise that won't happen again in the future, circumstances have changed, and I do find myself with the time to work on this project again. At this stage I believe this will continue to be the case, and I'll be able to consistently move this emulator forward.

I'm keeping things low key for now, but I'll be putting out a new release very soon, possibly in less than 24 hours. This release will include performance and usability enhancements, a few new features, and various assorted bugfixes. This is mainly a housekeeping release, to clear the decks for bigger work to come.

I've been pondering what I should be focusing on for new development over the last few days, and I feel to stay true to the goals of this project, that has to be accuracy. Although there are a lot of new cool features and enhancements I want to build, Exodus currently falls well short of where it should be in terms of accuracy, and this is primarily down to a lack of sub-opcode level external bus timing accuracy in the 68000 core. While no other Mega Drive emulator does this correctly either, they bend the timings of other system events to work around this limitation and make mainstream games run. I have deliberately avoided doing that in Exodus, and as a result there are numerous games I know of that don't function correctly as a result. This is where I'll be focusing the next development stages, aiming to get 100% cycle accurate M68000 and VDP interaction as a priority. You need to be able to measure accuracy though, so this process will involve hardware testing, and producing test ROMs. By the end of this process, I'll deliver some ROMs which can act as a regression test and a measuring stick, to compare timing accuracy between emulators and the real hardware. I already know roughly how it's going to work, and it's going to be pretty well impossible to bodge, so it'll be interesting to see the results. If you thought OverDrive 2 was brutal on emulators, just wait for this one.....

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If you wish to make a donation to show your appreciation for this project, you can do so here. Your donation may go towards the hosting costs of the website, or equipment or reference hardware to assist in the development of Exodus. It may also go towards a bunch of flowers for my beautiful wife, to say thanks for your support and patience all those nights I stayed up late working on this project.