Thanks for all the beers!

You are correct of course. But I do this mostly for my own benefits. To make my games play better, for sure. The technical side of it is great fun -- one small puzzle after another -- but that's not what rocks my boat. I am completely fascinated by the question what makes a game a good game. Stuff like risk-reward, score balance, game progression, multiplayer fairness, varied game play, etc. Maybe one day I will try to design a game from scratch. In the mean time I find that testing different ideas in existing games is a total blast. If you look at the progression of my patches --- Jungle Lord (new tricks), Pembot and TCM --- the changes have become more and more complex. I am looking forward to my next project, which will probably be a WPC.

Therefore, while I really appreciate your tips they are not necessary to keep me motivated. More important has been the input that you provided in this thread. The ideas, and also the feedback on mine, especially from the beta testers. The TCM patch would not be what it is without you!

Occasionally I get asked for the checksums of the patched ROM images for verification that the patching worked correctly. This is not necessary with the xdelta patch format, which uses internal checksum verification. However, since there are other uses for the checksums, here are the MD5 hashes for version JP-1.0:

daf15a5f960368d7ad7e917c124179fd TCM_U26.bin
208f879db303fad4367f2f85a1a7620d TCM_U27.bin

I have implemented most of the changes I want to make but there are a few things on my list left to-do. At the moment, I cannot play my game because the negative side of my high-voltage supply is still bad. Should not be very difficult to fix but I will have to order parts. So this will take a couple of weeks at least, probably longer because work is busy. Since some of the code changes are quite low level, another round of testing will be required. My goal is to send out the test version sometime in June. If all goes well and there are no serious bugs an update sometime in August looks reasonable.

I appreciate the offer! This thread describes the initial symptom and underlying problem (wrongly installed capacitor), as well as the secondary problem I am left with (insufficient voltage in the negative high-voltage side). Let's continue our discussion there.

TCM In The Wild

I'd like to share the following feedback I got as a PM for operators considering the patch:

TCM is working great! I've had it my arcade (along with 43 other pinballs) for the past 4 months. I haven't had any issues.

We added the game back in to our weekly tournament and nobody has complained. Our top tournament players know the differences and think it's fair.

Bad Cats is consistently one of our top played games at $0.50c per game, xxx-xxx plays per month.

I did disable the start-button menu.

If there are other operators running the code, please let me know. I'd like to make a post listing TCM on location.

Awesome! Thank you for letting me know.

Sure thing! Here's the link. Thank you!

When not buzzing I have been preparing a release candidate for version 1.1. One of the features I have not received any feedback on is they way TCM deals with "phantom" fish target hits. That's when the opto wheel of the fish target stops in a position where even the slightest vibration causes the opto to close. With the current code (which is almost completely identical to release version 1.0) I very rarely get any phantom closures any more, which means that the filtering works quite well on my game. Not that I think that I can do very much about this for the next release, but I still would like to know how this filtering has been working on other games.

This is something affecting mainly those who ran the LA-2 ROM before switching to TCM.

I think that this is consistent with my game: 6-7 phantom hits on a ball when the target is in the "phantom position". I consider this acceptable. With LA-2 stock ROM (or TCM AD52 set to WMS LA-2) I would get dozens and dozens of phantom hits on a single ball. If you do not like any phantom switch closures, you can set AD52 to WMS LA-5, which is what is used when you play ME-OW (hard) rules. The downside is that the fish target will be less responsive.

This does not sound normal to me. On my game the wheel gets stuck in the "bad position" maybe once every 30-50 games, not "every few games". If you get phantom hits every few games there is something else that's wrong with it, I think. (See also my next post.)

If you want to test the fish target with the glass off, you must first set AD52 to WMS LA-2 so that you actually see all the switch hits. Then you need to remove the ball from the shooter lane, because all fish switch hits are suppressed until the ball has been launched. You can now move the target and you should get a switch closure for every half rotation of the opto wheel but none otherwise. Perhaps I should make a youtube video that demonstrates how the target should react.

There is another test you can do when you think you are getting phantom hits: stop playing the game, remove the glass. Usually (but not always) you can cause additional phantom hits by bumping the playfield with your fist (not very hard). More importantly, if you move the fish target every so slightly, the phantom hits must disappear. If they don't you have a different problem.

My game used to have the same problem. Drove me nuts. For several months I "solved" the problem by trying to block LED light from interfering with the drop-target optos with cardboard "light guards" and electrical tape. These fixes always worked for a short while (a few hours to a couple of weeks). After several months of this I finally had the great idea of trying to re-seat the target-bank connectors. This solved the problem completely. My light-guard "solution" worked temporarily most likely because every time I fitted a "light guard" I touched the cables and connectors.

If this can happen to the drop target optos, it probably can happen to the fish target, too. So if you have trouble, you should try to reseat that connector as well.

That's how it's supposed to work, one or two is great.

Thanks for the tip about cracked pins --- I'll check that later today.

If you installed the original Williams LA-2 ROMs for the test, you are fine. If you did the test with the TCM patch installed but with the BAD FISH handler set to WMS LA-2, on the other hand, then your test did not do what you thought it did, because even with this setting the software suppresses some switch hits it knows to be bad. For example when the skill shot is active. If you want to really test the hardware and nothing but the hardware, you should first use the switch test from the diagnostics. If that works and you still have doubts, you can install the original LA-2 ROM, which does not filter the switch target at all. For every full rotation of the opto wheel you should get exactly 4 fish target hits, two for the switch closures and two for the switch openings.

I suspect that you probably burned the PinMAME ROM image, which is 16KB, into a 27256 EPROM, which is a 32KB chip. This won't work. There are two different solutions:

1. Double up your PinMAME U26 ROM image to create a 32KB file that contains the L2 code twice and burn this file on a 27256 EPROM chip.
2. Use a 27128 instead of a 27256 EPROM instead. (Williams used two 27256 EPROM chips for Bad Cats, likely because of cost reasons.)

UPDATE -- Change Log for Release JP1.1

No more known bugs to fix and I have implemented the last of my planned improvements. I am planning to do some more testing this week and, hopefully, send a version out to the testers next week. This post describes the changes since the initial release version (JP1.0).

Game Rules Changes

All game rules changes should be considered tentative. Feedback is particularly welcome on these!

1. The Curiosity Spin is disabled (outlane lamps turned off) when an Extra Ball is awarded while Curiosity Spin is lit. The idea is that the CS should not be enabled for 2 balls, which it is with custom code and JP1.0 when you score an EB on ball 3 without cashing in the CS. (An alternative solution would be to keep the CS lit but do not light it when playing the EB. While writing this, I am beginning to wonder if this would be a fairer solution, because it enables the CS for exactly one ball.)
2. When playing with TCM easy rules (SEAFOOD) and the 20M shot it lit, the unlimited 1M shot remains lit until the 20M shot is scored (no change from JP1.0). In version JP1.0 the Trashcan shot was disabled during this progression so that the player would remain focused on the 20M. In version 1.1 the Goldfish Ramp and Drop Targets are disabled as well, for the same reason. (I don't think that it is necessary to disable the inlanes or Fish Target, but I can be persuaded otherwise.)
3. I have integrated the timer and singles-award rules for the drop targets. This change is particularly important when playing with hard (MEOW) or tournament rules. With JP1.0, drop target timers are always started when playing TCM with hard rules, or after the first Jackpot has been lit when playing normal or easy. With JP1.1 the timers are only started when more than one target is hit simultaneously. Essentially, this extends the TCM idea of the single targets as more valuable to the hard rules. The main side effect is that it has become somewhat easier to drop the 3 bank in hard mode, because accidentally dropping the three targets as singles only is not very rare. For me, the updated rules make the timed 5-bank (birds) much more interesting.
4. I tried but will not include the idea to change the target banks to award a letter with the first drop when playing easy rules, instead of pre-lighting the B-A-D letters. Most importantly, this change unbalances the game quite badly: For all but the most novice players, it makes lighting the Jackpot super fast, as it essentially just adds another letter to each target bank award. As a result, the Jackpot becomes much easier than the Extra Ball and 5M shot, which means that the game becomes much more linear. For the novice, the change does not aid progress toward the Jackpot. All it does it give them two quick, easy and totally random letter awards early in the game, followed by no more awards, even though they hit the same shots again.

Cosmetic Improvements

1. Bird-bank and 20M flasher threads react more quickly to outlane drains.
2. Several cosmetic improvements to the Cat Nap, including turning off all flashers.
3. Display FX no longer freeze during ball launch.
4. With stock ROM and JP1.0 there sometimes is a long delay before Curiosity Spin is started. This always happens when the Unlimited Million mode is running but also occasionally at other times. Two separate fixes were implemented to address this issue. Testing will tell whether I nailed it or not.

1. Typo in AD14 string.
2. Incorrect display of 20M score in AD22.
3. Blinking cat-eyes included Extra Ball lamp and had some other cosmetic problems.
4. Starting new game while running the Seafood wheel no longer keeps wheel spinning indefinitely. (Bad Cats stock ROM bug.)
5. When playing with the Fish Special (AD44 NORMAL and AD07 SCORE, or AD44 EASY), the probability of the Special award from the wheel in version JP1.0 continuously increases from game to game, thus awarding the Special more and more frequently until the game is reset to default adjustments (Factory Reset).
6. In JP1.0 both the Jackpot and 5M values are sometimes displayed incorrectly (or not at all) during scoring, even though the correct score is awarded.
7. Consistent with the game manual, AD15 now limits the maximum number of Extra Balls per game. (Bad Cats stock ROM bug.)
8. In JP1.0 it was possible for the 20M FX thread to be killed, leaving the game completely muted until a new start was started.
9. Playing easy rules in JP-1.0 causes a few thread-system overflows every game, when threads that should be started are not. Most of the threads that are not started are ball-search threads, which can be ignored safely since there is one started with every score event. Most of the non-ball saver threads affected are display FX threads, which also are not important for game play. Every once in a while, however, a Jackpot increase or a letter award can be missed. The fact that nobody noticed anything during testing suggests that these glitches only happen when there is a lot going on game-play wise, which makes sense. In have solved this problem by introducing killable "background threads" to the Sys 11 thread system. When a thread has to be spawned and the thread list is full, the system kills a background thread to make space. Later, when the thread system is no longer fulll, the background thread is restarted. I have not managed to force a thread-system overflow with the glass on or off since implementing this final change.

1. Ensure that game is always unmuted on a ball drain, in case there is another bug affecting the 20M Shot FX.
2. Minor improvement to the bad fish handler.
3. Added code to ensure integrity of Jackpot temporary storage. (Not related to a known bug.)
4. Removed pointless call related to percentage Extra Ball award where the result is not used.
5. Carry out a "blind wheel spin" at the end of every wheel-spin-less game in order to avoid stacking high-value awards after multiple games are played without a wheel spin.
   

You can increase that yourself with AD12.

A bad solder joint like Tuukka suggested could explain that. I re-flowed my drop target connector joints yesterday, because I started getting the phantom switch hits back. I'll post here if the problems return.

My game cannot get above 10, either, but I thought that your game should be able to, because I assumed it was a European game. (According to the Bad Cats manual, both French and Western European games have AD12 defaults above 10.) Based on the code, if you have a "language" jumper installed at W7 the maximum limit is 99, otherwise it is 10. I have not seen this documented anywhere.

Yes, that is normal behavior. 20 seconds after any scoring event the ball search kicks in unless the game has the ball search disabled in the mean time. The shooter-lane switch disables the ball search when a ball is served. But when you touched the sling you caused a scoring event, and this first re-enables the ball search before sleeping for 20s and then firing the eject solenoids. The game will try three this times before giving up.

Since we're on the topic: in my game the ball search is 100% useless. There are a few ways the ball can get stuck but none of them in a way that it could be freed with any of the solenoids. I'll probably get rid of it on my own game and see if that changes anything, for better or for worse.

In both Pin Bot and Bad Cats, reading the jumper is one of the first things that the reset handler does, so this is done on every game boot. The code is identical in both games:

LDAA    PIA_2800(diagnosticIO_data)

STAA    W7_language_jumper

After this, the sign flag of _W7_language_jumper is set when a jumper is installed. In Pin Bot the jumper selects German Language. In Bad Cats, the only thing it does is increase the max credits limit. I do not know why this limit is there, but I'd like to keep it, because it is consistent with the manual and because in general I try to not change things that I do not have to change.

Nice patch idea, but the opcode for LDAA with a 16-bit address is $B6, so you'll have to increase the operand of the patch LDAA to $57, I think. I never worry about the check sum, though, because 7eleven deals with that automatically:

checksum_block_B000: .DB @CHECKSUM_BYTE

Thank you for checking! I don't have my game at home, but now that I am here I verified I also have a jumper installed at W7. But doesn't this mean that your patch would have worked after all?

Clever trick for keeping the checksum constant!

I have added two more changes to the list for version 1.1:

1. There is now a nice little acknowledgment FX during the bonus count when the bonus multiplier has been maxed out.

2. Sometimes I like aborting a lousy game while the last ball is still draining. With TCM 1.0 I lose the ball saver on ball 1 of the new game when doing that. I have begun implementing a cleaner way to abort a running game so that the new game is only started once the ball from the aborted game has drained.