famicommander Posted November 21, 2023 Share Posted November 21, 2023 2 hours ago, Thomas Jentzsch said: What is wrong with Stella? Nothing. Everything is wrong with Prosystem, though. 1 Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted November 21, 2023 Share Posted November 21, 2023 49 minutes ago, famicommander said: Nothing. Everything is wrong with Prosystem, though. Which emulator is the 2600+ using? Quote Link to comment Share on other sites More sharing options...
famicommander Posted November 21, 2023 Share Posted November 21, 2023 Just now, jaek_3 said: Which emulator is the 2600+ using? It's using an ancient version of ProSystem for 7800 games, which is why the 7800 emulation is absolutely trash. It's using a modern version of Stella for 2600 games, which is why the 2600 games which the cart dumper can actually handle run great. 3 Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted November 21, 2023 Share Posted November 21, 2023 14 minutes ago, famicommander said: It's using an ancient version of ProSystem for 7800 games, which is why the 7800 emulation is absolutely trash. How is the situation of 7800 emulators in general? Is the ProSystem frequently updated? And are there better alternatives? Quote Link to comment Share on other sites More sharing options...
+splendidnut Posted November 21, 2023 Share Posted November 21, 2023 The latest / greatest for 7800 is the A7800 emulator, which is based on MESS/MAME codebase. I've heard claims that the CPU in the Atari 2600+ is not powerful enough to run it. But I don't believe that for a second. I'm guessing that they don't want/can't afford to invest the time / effort in developing a UI to replace the crap-tastic MAME one. Quote Link to comment Share on other sites More sharing options...
zzip Posted November 21, 2023 Share Posted November 21, 2023 3 minutes ago, splendidnut said: The latest / greatest for 7800 is the A7800 emulator, which is based on MESS/MAME codebase. I've heard claims that the CPU in the Atari 2600+ is not powerful enough to run it. But I don't believe that for a second. I'm guessing that they don't want/can't afford to invest the time / effort in developing a UI to replace the crap-tastic MAME one. It is possible to run a7800 without touching the UI at all. Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted November 21, 2023 Share Posted November 21, 2023 13 minutes ago, zzip said: It is possible to run a7800 without touching the UI at all. AFAIK the 2600+ has no UI anyway. 1 Quote Link to comment Share on other sites More sharing options...
zzip Posted November 21, 2023 Share Posted November 21, 2023 Just now, Thomas Jentzsch said: AFAIK the 2600+ has no UI anyway. Yeah it wouldn't make sense, I would think you would just want it to run the dump of the cart you inserted. 1 Quote Link to comment Share on other sites More sharing options...
+karri Posted November 21, 2023 Share Posted November 21, 2023 I use the a7800 while developing. The code is C+ which is a good candidate for optimisation. The Rockchip has some very advanced features like: DMAC Micro-code programming based DMA The specific instruction set provides flexibility for programming DMA transfers Linked list DMA function is supported to complete scatter-gather transfer Support internal instruction cache Embedded DMA manager thread Embedded 4 shader cores with shared hierarchical tiler Separate vertex(geometry) and fragment(pixel) processing for maximum parallel throughput Bit Blit with Strength Blit, Simple Blit and Filter Blit Color fill with gradient fill, and pattern fill Line drawing with anti-aliasing and specified width High-performance stretch and shrink So imho you can do anything with this chip in real time. But of course there is no support for these advanced hw features in any emulator. If you just use the CPU there may be a problem. If you use the hardware features of the chip you should be able to run 7800 games at full speed. 3 Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted November 21, 2023 Share Posted November 21, 2023 16 minutes ago, karri said: High-performance stretch and shrink This is the most useful one. Stella uses SDL 2, which uses hardware acceleration. Quote Link to comment Share on other sites More sharing options...
famicommander Posted November 21, 2023 Share Posted November 21, 2023 (edited) 1 hour ago, Thomas Jentzsch said: How is the situation of 7800 emulators in general? Is the ProSystem frequently updated? And are there better alternatives? ProSystem is about as bad as you could do. It fails almost every test on the 7800 test suite and even many of the games that are marked as "working" have speed issues, control errors, graphical glitches, awful sound, etc. A7800 is the standard for 7800 emulation but apparently the CPU in the 2600+ is too big of a piece of crap to run it. The last version of Prosystem from the original developer was over 9 years ago but there have been many community enhancements since then that have been completely ignored by Atari. But based on some of the behaviors the 2600+ exhibits they may actually be using the 2009 official build instead of the 2013 official build, but again, even the 2013 build sucks. Even if they used the latest and greatest community build it would still be far worse than A7800, but it would be way better than what we got. Edited November 21, 2023 by famicommander Quote Link to comment Share on other sites More sharing options...
+karri Posted November 21, 2023 Share Posted November 21, 2023 21 minutes ago, Thomas Jentzsch said: This is the most useful one. Stella uses SDL 2, which uses hardware acceleration. Blowing up the textures into modern TV screen is one important hw feature. Another would be to program the DMA to faithfully duplicate the operations of the MARIA chip. It is micro-programmable. The interesting things with micro-programmable DMA is that you can do the processing while the data is fetched before it reaches the destination. This means insanely short delays. Almost like fpga... This is not a quick fix as you would need to write everything from scratch. 1 Quote Link to comment Share on other sites More sharing options...
zzip Posted November 21, 2023 Share Posted November 21, 2023 9 minutes ago, karri said: It is micro-programmable. The interesting things with micro-programmable DMA is that you can do the processing while the data is fetched before it reaches the destination. This means insanely short delays. Almost like fpga... But can it be implemented in Javascript? 1 Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted November 21, 2023 Share Posted November 21, 2023 10 minutes ago, karri said: Blowing up the textures into modern TV screen is one important hw feature. Another would be to program the DMA to faithfully duplicate the operations of the MARIA chip. It is micro-programmable. The interesting things with micro-programmable DMA is that you can do the processing while the data is fetched before it reaches the destination. This means insanely short delays. Almost like fpga... This is not a quick fix as you would need to write everything from scratch. I figure most emulators use a library to abstract hardware access. 1 Quote Link to comment Share on other sites More sharing options...
AtariLeaf Posted November 21, 2023 Share Posted November 21, 2023 16 minutes ago, famicommander said: ProSystem is about as bad as you could do. It fails almost every test on the 7800 test suite and even many of the games that are marked as "working" have speed issues, control errors, graphical glitches, awful sound, etc. A7800 is the standard for 7800 emulation but apparently the CPU in the 2600+ is too big of a piece of crap to run it. Well that's disappointing as 7800 support was a big draw for this over, say, the retron. I've personally only tried 4 games, centipede, food fight, and donkey kong run fine but asteroids is unplayable with the phantom random hyperspace jumps without a button press. I would assume other two button games may exhibit odd behavior but have yet to try them Quote Link to comment Share on other sites More sharing options...
zzip Posted November 21, 2023 Share Posted November 21, 2023 2 minutes ago, Thomas Jentzsch said: I figure most emulators use a library to abstract hardware access. Most likely, if you tried to do it this low-level with DMA access, might the processor's endieness become an issue? Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted November 21, 2023 Share Posted November 21, 2023 1 minute ago, AtariLeaf said: Well that's disappointing as 7800 support was a big draw for this over, say, the retron. Fortunately I am more retro than you. But even the 2600 section needs improvement. Fortunately a lot of things can be updated. 1 Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted November 21, 2023 Share Posted November 21, 2023 1 minute ago, zzip said: Most likely, if you tried to do it this low-level with DMA access, might the processor's endieness become an issue? Low-level everything is an issue. Quote Link to comment Share on other sites More sharing options...
+karri Posted November 21, 2023 Share Posted November 21, 2023 1 minute ago, Thomas Jentzsch said: I figure most emulators use a library to abstract hardware access. True. But everything does not always fit into libraries. If we restrict us to libraries there is accelerator libraries available for this chip. The Rockchip has a lot of features. I don't know what would be the best library. And can this library be used for a PC also? Or would the implementation by 2600+ specific? But it is the same development that has happened in other equipment. Vulcan optimizes the use of the hardware instead of focusing on drawing primitives. But you get more speed the closed to the hw you program. Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted November 21, 2023 Share Posted November 21, 2023 7 minutes ago, karri said: But you get more speed the closed to the hw you program. Yes, but someone has to pay this development. And that's a lot! Quote Link to comment Share on other sites More sharing options...
Emehr Posted November 21, 2023 Share Posted November 21, 2023 17 minutes ago, AtariLeaf said: asteroids is unplayable with the phantom random hyperspace jumps without a button press This brought back a core memory playing 7800 Asteroids on real hardware. Is this the bug where your ship is in a constant hyperspace loop? If I remember correctly (and I could very well be mistaken) this would happen when I had a 2600 joystick plugged into my 7800. I'd double check but my 7800 is on the fritz 😞 Quote Link to comment Share on other sites More sharing options...
AtariLeaf Posted November 21, 2023 Share Posted November 21, 2023 3 minutes ago, Emehr said: This brought back a core memory playing 7800 Asteroids on real hardware. Is this the bug where your ship is in a constant hyperspace loop? If I remember correctly (and I could very well be mistaken) this would happen when I had a 2600 joystick plugged into my 7800. I'd double check but my 7800 is on the fritz 😞 I've never noticed it on a real 7800. On the 2600+, I tried a europad and two modded nes pads but the warps were random in intervals. Sometimes a few seconds apart, sometimes a minute or more. Quote Link to comment Share on other sites More sharing options...
Giles N Posted November 21, 2023 Share Posted November 21, 2023 (edited) @Blinky You could’ve warned us fainthearted, this thread contained explicit images of a cut-open console, with all interiors showing as it undergoes surgical dissection… This is hard to watch, man, really hard… Edited November 21, 2023 by Giles N Quote Link to comment Share on other sites More sharing options...
+karri Posted November 21, 2023 Share Posted November 21, 2023 59 minutes ago, Thomas Jentzsch said: Yes, but someone has to pay this development. And that's a lot! True. Quote Link to comment Share on other sites More sharing options...
tradyblix Posted November 21, 2023 Share Posted November 21, 2023 (edited) 4 hours ago, Thomas Jentzsch said: How is the situation of 7800 emulators in general? Is the ProSystem frequently updated? And are there better alternatives? Personally speaking there's kinda 2 camps here. There's average users, like me, for which all my 7800 games (so far) I care about that are NTSC work acceptably for me. I only just got it tho so that might change if random reboots happen a lot but so far they haven't. Also I had some sound corruption in Jungle Hunt, and that was a Stella game, so stella isn't scott free yet either. Also I noticed some finickyness with how it loads stuff, so that might vary on a unit by unit basis. Then there are enthusiasts, like some of you here, who care about cycle accuracy and bugs and stuff and they are more critical. That's probably totally valid, I wouldn't know, but it didn't stop me getting to level 13 in robotron today and having a blast. So, I think one should have some perspective. Although the PAL issues suck and certainly i'd never get in the way of improvements to the emulation. Edited November 21, 2023 by tradyblix Quote Link to comment Share on other sites More sharing options...
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