+batari Posted September 17, 2015 Share Posted September 17, 2015 What type of errors would these conflicts cause? I imagine the Concerto has several of the same components that the XM module does, mainly extra on board RAM and Hokey/Pokey. I thought of this as well: Since the XM uses a slightly different address compared to native carts, could a "dual Pokey" homebrew sound demo could be created to utilize both the Concerto and XM Pokey? As you probably guessed, the sig is to stop XM from mapping hardware at the same locations that Concerto does, such as the XM's POKEY, extra RAM, and HSC (if XM is so equipped; I can't remember.) I don't know if a dual Pokey would work. With just audio out, no damage is possible. I don't know how it would sound, though. Link to comment Share on other sites More sharing options...
+batari Posted September 17, 2015 Share Posted September 17, 2015 Oh yeah, I forgot to ask you all something. I understand the CC2 does not support the A78 files that the emulators require, but instead uses .bin files, which lack a header with information about the game, so the CC2 uses a menu.cc2 configuration file instead that has all the bankswitching information for all the .bin files. A78 files have bankswitch information in a header, though, so no configuration file is necessary with them, and since emulators generally require A78 (as far as I know), Concerto currently requires A78 files too. However, I know there are going to be some who just want to pop their MMC card from their CC2 into Concerto and expect their mixed bag of .bin files to "just work," and will be unhappy if they don't. The problem is it's hard enough to properly detect the bankswitching type of those Atari 2600 .bin files (we use heuristics), but with Atari 7800 files in the mix that are the same size as larger 2600 games, detection could be much more difficult, which may take up space that could be used for other features of Concerto down the road. So I'm wondering, does anyone (other than CC2 users, and those who burn EPROMs, etc) actually use Atari 7800 .bin files anymore? Link to comment Share on other sites More sharing options...
Andromeda Stardust Posted September 17, 2015 Share Posted September 17, 2015 bin extension is generally used for 2600 ROMs though a26 is also used. My no intro set used a26 file extension instead of bin. Regardless, that would make quite a conundrum if both formats used the same file extension. Also aside from utilising TIA audio, 7800 and 2600 are totally different formats. Just curious, how does one switch back into 2600 mode once the console is booted to the menu as a 7800? Obviously CC2 and Concerto are both capable of this. Also are hybrid ROMs possible, for instance a ROM using the TIA for video output instead of the Maria, and the 7800/6502's expanded address space for RAM/ROM? That would be cool... Link to comment Share on other sites More sharing options...
+batari Posted September 17, 2015 Share Posted September 17, 2015 You write a value to INPTCTRL to switch to 2600 mode (offhand, I recall the value is $1D or something like that). Once in 2600 mode, you can't go back to 7800 mode without a power cycle as the hardware prevents this. The 7800 can also be locked into 7800 mode, but comes out of BIOS unlocked. Thankfully the creators of the 7800 did not lock it on boot. I think the only hybrid mode possible is 7800 mode with Maria disabled and TIA enabled, but as best as I can tell, only about half the TIA registers are available in this mode so it's not terribly useful, though it might be an interesting exercise to see what is possible under those circumstances. Link to comment Share on other sites More sharing options...
RevEng Posted September 17, 2015 Share Posted September 17, 2015 A78 files have bankswitch information in a header, though, so no configuration file is necessary with them, and since emulators generally require A78 (as far as I know), Concerto currently requires A78 files too. However, I know there are going to be some who just want to pop their MMC card from their CC2 into Concerto and expect their mixed bag of .bin files to "just work," and will be unhappy if they don't. I think A78-only support is the way to go, and you should spend your time and ROM on other features. These days all homebrew authors provide A78 files with their games, and all of the original commercial games are easily found with headers. Technically the emulators can be made to work with BIN files, but anything other than vanilla hardware has the user providing all of the info that would have otherwise been provided through the A78 header. If there's really a need to transition CC2 users, it would be better just to have an external utility that opens the menu file and creates A78 files from their BINs. Just to make sure you're aware, last year a header bit for pokey@$450 was defined, and the old bit was made to specify pokey@$4000. This was added to MESS/MAME at that time. 5 Link to comment Share on other sites More sharing options...
78001987 Posted September 17, 2015 Share Posted September 17, 2015 Oh yeah, I forgot to ask you all something. I understand the CC2 does not support the A78 files that the emulators require, but instead uses .bin files, which lack a header with information about the game, so the CC2 uses a menu.cc2 configuration file instead that has all the bankswitching information for all the .bin files. A78 files have bankswitch information in a header, though, so no configuration file is necessary with them, and since emulators generally require A78 (as far as I know), Concerto currently requires A78 files too. However, I know there are going to be some who just want to pop their MMC card from their CC2 into Concerto and expect their mixed bag of .bin files to "just work," and will be unhappy if they don't. The problem is it's hard enough to properly detect the bankswitching type of those Atari 2600 .bin files (we use heuristics), but with Atari 7800 files in the mix that are the same size as larger 2600 games, detection could be much more difficult, which may take up space that could be used for other features of Concerto down the road. So I'm wondering, does anyone (other than CC2 users, and those who burn EPROMs, etc) actually use Atari 7800 .bin files anymore? one google search would bring someone to a myriad of links to the entire 7800 romset in .a78 format, which is about 10Mb. total. If someone can't be bothered to do that after spending $100 or $150 on a device like this, shame on them. Link to comment Share on other sites More sharing options...
+FujiSkunk Posted September 17, 2015 Share Posted September 17, 2015 I wonder if someone could write a script that takes a directory full of BIN files and a CC2-menu-formatted text file and creates A78 files out of them. At any rate, I imagine that kind of venture would be a lot easier than writing new firmware to support autodetection. And even that's assuming people don't have the A78's in their collection already. I'm all for making the Concerto A78-only. Link to comment Share on other sites More sharing options...
Andromeda Stardust Posted September 17, 2015 Share Posted September 17, 2015 Just use a78 for 7800 ROMs and allow either a26 or bin for 2600 ROMs (in addition to the Harmony supported extensions). Link to comment Share on other sites More sharing options...
78001987 Posted September 17, 2015 Share Posted September 17, 2015 Aren't the vast majority of a78 roms hosted right here at AA? Link to comment Share on other sites More sharing options...
+Mitch Posted September 18, 2015 Share Posted September 18, 2015 Just handling A78 files should be fine. Unfortunately, there's a few out there with bad headers, Commando seems to be the worst one. I have a complete set of clean A78 files for all the original games if anyone needs them. 7800 bin files are not that bad though since there is only a couple of non-standard banking boards (Absolute 64K and Activision 128K). Stuff with extra RAM or audio chips would be more difficult. Incidentally, are you supporting the old Activision ROMs or the new dumps? Mitch Link to comment Share on other sites More sharing options...
+DrVenkman Posted September 18, 2015 Share Posted September 18, 2015 I have the set of A78's that periodically get posted in the MESS/MAME 7800 posts that Trebor makes. Are those the "good" or "bad" header versions, and "new" or "old" Activision dumps? Inquiring minds and all that. Link to comment Share on other sites More sharing options...
+Mitch Posted September 18, 2015 Share Posted September 18, 2015 Unless something has changed, I think they are using my set so they should be good. As far as I know, nothing supports the new Activison dumps yet. You most likely have the old dumps. Mitch Link to comment Share on other sites More sharing options...
Shawn Posted September 19, 2015 Share Posted September 19, 2015 .a78 is fine by me Link to comment Share on other sites More sharing options...
Shawn Posted September 19, 2015 Share Posted September 19, 2015 Just use a78 for 7800 ROMs and allow either a26 or bin for 2600 ROMs (in addition to the Harmony supported extensions). .a26 is nothing more than a re-named bin. There is no data associated with it. Link to comment Share on other sites More sharing options...
Andromeda Stardust Posted September 19, 2015 Share Posted September 19, 2015 .a26 is nothing more than a re-named bin. There is no data associated with it. I'm well aware of that. Both are common usage. Some ROM sets have one file extension and others something else. Renaming 1000s of files is a pain in the ass and isn't necessary unless you're so cheap you're using the same SD card in multiple flash carts for different systems and can't reorganise them into separate folders. Most flash cards need the ROMs separated by alphabet or other nemonic anyway as there's typically a limit of 250 or so file listings per directory. Link to comment Share on other sites More sharing options...
Andromeda Stardust Posted September 19, 2015 Share Posted September 19, 2015 Unless something has changed, I think they are using my set so they should be good. As far as I know, nothing supports the new Activison dumps yet. You most likely have the old dumps. Mitch What are the "new" dumps supposed to be for? A ROM is a ROM. It's either a good dump or a bad one. If it don't match what's on the actual ROM chip, it's bad. Link to comment Share on other sites More sharing options...
+batari Posted September 19, 2015 Share Posted September 19, 2015 Just handling A78 files should be fine. Unfortunately, there's a few out there with bad headers, Commando seems to be the worst one. I have a complete set of clean A78 files for all the original games if anyone needs them. 7800 bin files are not that bad though since there is only a couple of non-standard banking boards (Absolute 64K and Activision 128K). Stuff with extra RAM or audio chips would be more difficult. Incidentally, are you supporting the old Activision ROMs or the new dumps? Mitch I suspect the old ones, as I have had most of these files for a while. I will check once I am at my computer. The problem with bin files wasn't necessarily that bankswitch detection would be hard, but I was worried about discerning them from 2600 bin files. I did figure out a heuristic for that last night though: While it only detected about 90% of 7800 bin files properly, of 2000+ 2600 games, not a single one was detected as a 7800 game. Now in just need to find the space for it in the Concerto bios. Also, I have found some weird a78 files. Some are (for example) exactly 32k and not 32k+128 bytes as they should be, and naturally these do not load right, so I need to add another check for these too. 1 Link to comment Share on other sites More sharing options...
Mord Posted September 19, 2015 Share Posted September 19, 2015 So I'm wondering, does anyone (other than CC2 users, and those who burn EPROMs, etc) actually use Atari 7800 .bin files anymore? Being stuck with emulators myself, naturally I just use the a78 files. Anything that makes it easier to get a game to Just Work is ok by me. Link to comment Share on other sites More sharing options...
RevEng Posted September 19, 2015 Share Posted September 19, 2015 [...]Also, I have found some weird a78 files. Some are (for example) exactly 32k and not 32k+128 bytes as they should be, and naturally these do not load right, so I need to add another check for these too.Do they actually have headers and run in MAME/MESS? I've run across bins that were just renamed to have the .a78 extension, but have no header. Link to comment Share on other sites More sharing options...
Andromeda Stardust Posted September 19, 2015 Share Posted September 19, 2015 (edited) Do they actually have headers and run in MAME/MESS? I've run across bins that were just renamed to have the .a78 extension, but have no header. Problem with emulators is they store the checksum of known ROMs and if they come across the a78 or *insert format* with a missing or incorrect header, they just run the game anyway with proper settings since the ROM was properly detected. So unless the game is a hack, homebrew, or proto, the emulator already knows how to run it. It only actually needs the header if the game isn't in the database. Even then, the emu can use heuristics to detect the appropriate mapper and get it to run. This would be a big problem on flash carts without "infinite" resources like a PC or mobile device. The flashcart has basically one shot to get it right upon load, and don't have the luxury of a checksum database or advanced heuristic algorithms. The fact that Harmony loads 99% of Atari 2600 ROMs without headers and all sorts of crazy bank schemes is a miracle in and of itself. Edited September 19, 2015 by stardust4ever Link to comment Share on other sites More sharing options...
RevEng Posted September 19, 2015 Share Posted September 19, 2015 Problem with emulators is they store the checksum of known ROMs and if they come across the a78 or *insert format* with a missing or incorrect header, they just run the game anyway with proper settings since the ROM was properly detected. So unless the game is a hack, homebrew, or proto, the emulator already knows how to run it. This isn't true at all for MAME/MESS. It will only run a headerless bin if the file matches the filename+extension+checksum stored in its database, is actually stored in your roms directory, and you launch MAME/MESS with the "software name" rather than the file name. Otherwise it will only run ROMs with valid A78 headers, so if an A78 file runs you can be sure it has a good header. Link to comment Share on other sites More sharing options...
+Mitch Posted September 19, 2015 Share Posted September 19, 2015 Do they actually have headers and run in MAME/MESS? I've run across bins that were just renamed to have the .a78 extension, but have no header. I suspect this is correct. Someone thought they were like 2600 ROMs and just changed the file extension. Mitch Link to comment Share on other sites More sharing options...
Andromeda Stardust Posted September 20, 2015 Share Posted September 20, 2015 (edited) You can easily check based on the file size using the properties tab in Windows Explorer. You can view these easily by displaying "details" under the view menu. IE if the ROM is listed as 16.1 or 32.1 or 48.1 kbytes, then it has the 128 byte header. If Windows says the ROM is 16.0 or 32.0 or 48.0 kbytes, then the header is missing. Either way the ROM should be some integer multiple of 16kbyte ie N*16,384 bytes plus 128 if it the ROM is valid with a proper header. Edited September 20, 2015 by stardust4ever Link to comment Share on other sites More sharing options...
+batari Posted September 20, 2015 Share Posted September 20, 2015 Yes, I am doing !((size-128)%16384) for size, but also checking for a valid A78 header to be sure. As for headerless A78, I will verify that is the case when I am back at my computer. So how many checksums are in MESS? Harmony BIOS uses md5 for some games so there's no reason why I couldn't do that for Concerto too, provided there aren't too many. Link to comment Share on other sites More sharing options...
CPUWIZ Posted September 20, 2015 Share Posted September 20, 2015 IMHO, checksums inside the cart are crap, that removes the ability for people to make graphics hacks, trainers, etc.! 1 Link to comment Share on other sites More sharing options...
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