Shift838 Posted August 14, 2015 Share Posted August 14, 2015 I think I found a bug on GAMECART5 for MunchMan. while attempting to conquer the high score. I noticed that I could not get past level 1! The entire screen has the chainlink laid down but it never goes to the next level. I tested it on actual hardware and classic 99 with the same results. See screenshot. I don't see anywhere a link is not completed. Anyone else have this issue ? Quote Link to comment Share on other sites More sharing options...
Opry99er Posted August 14, 2015 Share Posted August 14, 2015 Hmmm... Do the levels increase in difficulty/speed? If not, that version should probably not be played for the High Score contest. Quote Link to comment Share on other sites More sharing options...
Shift838 Posted August 14, 2015 Author Share Posted August 14, 2015 i have been playing my EA#5 version, which is the one I posted and it works. Quote Link to comment Share on other sites More sharing options...
+save2600 Posted August 14, 2015 Share Posted August 14, 2015 Yep, it's borked alright! Quote Link to comment Share on other sites More sharing options...
Tursi Posted August 14, 2015 Share Posted August 14, 2015 This is (likely) the bug we found when doing the scratchpad loader. Munchman has a bug where it counts down the number of dots left (or links left) as a byte, but compares to zero as a word. If the other byte in scratchpad was not zero when Munchman started, you can never finish the level. 1 Quote Link to comment Share on other sites More sharing options...
Shift838 Posted August 14, 2015 Author Share Posted August 14, 2015 This is (likely) the bug we found when doing the scratchpad loader. Munchman has a bug where it counts down the number of dots left (or links left) as a byte, but compares to zero as a word. If the other byte in scratchpad was not zero when Munchman started, you can never finish the level. Is there a fix for it? Quote Link to comment Share on other sites More sharing options...
Tursi Posted August 14, 2015 Share Posted August 14, 2015 Is there a fix for it? Just making sure your loader zeros scratchpad... we didn't code a fix for it since everyone already has a binary. I went and hunted down the message where we described the bug over on the SWPB group on Yahoo: https://groups.yahoo.com/neo/groups/SWPB/conversations/topics/2280 Here's the skinny: I had ONE problem left which I have finally identified -- it is a bug inMunchman. Munchman uses the byte at >8335 to count how many links you have laid down. It uses a MOVB to initialize it. However, it uses INC @>8334 to increment it, which would probably be okay, but it ALSO uses C, rather than CB, to test it. Meaning if >8334, which Munchman /never/ initializes, is not >00, you can never clear the level. And that is what is happening. So, to fix, we just need to make sure >8334 is cleared before Munchman starts. It can go anywhere since it only needs to be done once. I dunno how many versions of Munchman are floating around out there, though.. I can patch the copy I have but will it do any good for anyone? Quote Link to comment Share on other sites More sharing options...
Shift838 Posted August 14, 2015 Author Share Posted August 14, 2015 Is there something we can just change in the binary eprom image with a hex editor? If so then I can do it for mine and report back. I just need to be told what to change. Quote Link to comment Share on other sites More sharing options...
Tursi Posted August 15, 2015 Share Posted August 15, 2015 I don't know anything about GAMES5... In theory, of course, the answer is yes, but you need to find somewhere to insert an extra instruction or two. Is it online here somewhere? I can take a quick peek. Quote Link to comment Share on other sites More sharing options...
Shift838 Posted August 15, 2015 Author Share Posted August 15, 2015 I don't know anything about GAMES5... In theory, of course, the answer is yes, but you need to find somewhere to insert an extra instruction or two. Is it online here somewhere? I can take a quick peek. Here you go.. Gamecart5.bin Quote Link to comment Share on other sites More sharing options...
Tursi Posted August 15, 2015 Share Posted August 15, 2015 It was tough to find a good place to put the clear... both the menu and Munchman are tightly packed and all the copy code is hard coded. I ultimately opted to put it in the copy loop itself, changing the bank switch code out to make room. This appears to work. It should not affect anything but Munchman. Because I shifted code around, it's more than a couple of bytes, but there's a text file included that shows what I changed. Gamecart5_TursiMunchmanHack.zip 1 Quote Link to comment Share on other sites More sharing options...
Shift838 Posted August 15, 2015 Author Share Posted August 15, 2015 It was tough to find a good place to put the clear... both the menu and Munchman are tightly packed and all the copy code is hard coded. I ultimately opted to put it in the copy loop itself, changing the bank switch code out to make room. This appears to work. It should not affect anything but Munchman. Because I shifted code around, it's more than a couple of bytes, but there's a text file included that shows what I changed. Gamecart5_TursiMunchmanHack.zip Thanks Tursi! Works like a charm.. Quote Link to comment Share on other sites More sharing options...
+arcadeshopper Posted August 18, 2015 Share Posted August 18, 2015 It was tough to find a good place to put the clear... both the menu and Munchman are tightly packed and all the copy code is hard coded. I ultimately opted to put it in the copy loop itself, changing the bank switch code out to make room. This appears to work. It should not affect anything but Munchman. Because I shifted code around, it's more than a couple of bytes, but there's a text file included that shows what I changed. Gamecart5_TursiMunchmanHack.zip Quote Link to comment Share on other sites More sharing options...
Gazoo Posted August 31, 2015 Share Posted August 31, 2015 Just now seeing this, wish someone would have sent me a PM. Thanks for the patch, Tursi. Always nice to see an alternate way of doing things. I've integrated the fix into the 1 meg gamecart as well. Gazoo 1megGames08312015.bin Quote Link to comment Share on other sites More sharing options...
Shift838 Posted September 1, 2015 Author Share Posted September 1, 2015 Just now seeing this, wish someone would have sent me a PM. Thanks for the patch, Tursi. Always nice to see an alternate way of doing things. I've integrated the fix into the 1 meg gamecart as well. Gazoo 1megGames08312015.bin Sorry Gazoo. I should have sent you over a PM. I dropped the ball on that one. Quote Link to comment Share on other sites More sharing options...
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