Gernot's tiny hacks

[Gernot]

...and not that tiny ones.

 

Since i was advised a couple of times to open the hacking thread in the programming sub-forum i decided now to do it.

 

As a first entry a little fix, it is known that Pac-Man counts the points of the fruit bonus double i fixed this by changing the values in the bonus table, certainly there is a multiplier but it's not to tell where or what if you can't disassemble the program, to find the table was quite easy because i knew which values i had to look for or a division of them, one can assume that instead of i.e. 100 points 10 points are listed and multiplied with 10 or a similar method.

 

I picked a possible multiplier which works for all values, in this case 20 and divided the bonus points by this to find the table (i.e. the first entry in the table is originally 10, points rewarded in the unaltered program are 200 which equals to a multiplier of 20, probably it is multiplied simply double and the multiplier would be the obvious 10).

 

Since the ATARI and the INTV release are exactly the same except for the hacked title screen in the INTV release you can apply this macro to the config file of both releases.

[macro]
; fixed bonus points (actual points equal displayed points)
p 78d5   5 ; (cherry 100 pts)
p 78d6   f ; (strawberry 300 pts)
p 78d7  19 ; (peach 500 pts)
p 78d8  23 ; (apple 700 pts)
p 78d9  32 ; (pineapple 1000 pts)
p 78da  96 ; (bell 3000 pts)
p 78db  96 ; (bell 3000 pts)
p 78dc  fa ; (key 5000 pts)
p 78dd  fa ; (key 5000 pts)

Of course you could enter any values in the table but keep in mind that they won't be displayed.

 

Yes i know we could have made use of this decades ago

 

---

 

Next will be an extended BRICKOUT hack, i know i posted it already and it is even present in my hacking blog but i added a couple of things to this proggy which i use as a sandbox.

Mainly i used it now to get comfortable with setting up the GRAM table and to toy around with the carts in it.

Edited July 28, 2021 by Gernot

[Zendocon]

I was thinking of doing just that, halving the point values of the prizes to offset the "double point value" bug.  Somebody else had hacked Pac-Man to make the ghosts slow and stupid, and this isn't one I ever got around to hacking myself.  I'm glad you saved me the trouble.

[Gernot]

Wasn't much trouble - rather a pleasure.

Who would like slower Ghosts?

I guess some would like them less predictable.

Not especially me i never was a brilliant Pac-Man player but neither i like the games to easy, arcade games are designed to be hard the rule of thumb if i remember this right was that a mediocre player should not play longer as three minutes with one credit.

I guess the Intellivision version can be annoying since the Ghosts are faster in comparison to Pac-Man compared to the arcade game, i assume they leak in behave and this is to balance this leak. Means the coin-op differs in behave for the Ghosts but i have the impression that they don't differ in the Intellivision Pac-Man which obviously makes the game easier. The slowest one can be surprising hard because he will change direction often while "Akabei" (the red one) hunts you and leads you in the arms of "Pinky".

A slower Ghost mustn't be easier to evade - at least not for the coin-op.

I feel they are very predictable in the Intellivison release, i'm not the one with the photographic memory like one of my friends in my youth but i can see it, if one take himself a little time he certainly would find a not to beat path for this game (like it was for the intentional Pac-Man as i've read back then). At least i follow a given path to start a level this could be extended with some patience.

Since Pac-Man is the only old game one of my very young comrades plays i even play it more often or watch while he plays (and utter stupid advises ).

He even took the opportunity to play the 256 Pac-Man and had blisters on his fingers after the first 128 - lol.

 

[Gernot]

A rather cosmetic fix, some games open with an olive screen instead of the intended black, e.g. (or the recent two ones are) "Thunder Castle" and "Vectron", this appears on my PAL hardware (dunno for NTSC) and as well in MAME or if run them in jzIntv with the sears exec (neither i can tell if this will be the case on the hardware, i just own a PAL inty and mainly therefore this fix i made).

 

Thunder Castle as it appears in MAME and on my PAL Intellivision.

 

and as it should and does now... apart from the altered credits of course, it was a "must" because it is a beautiful game, really it is.

 

Interesting is that the prototype "Mystic Castle" does not show this misbehave, sure it is right from the start quite different. Further there is an "easter egg" listed for "Thunder Castle" but i guess this will only work for the INTV cartridge release, it looks a bit to me that the electronically published "Thunder Castle" is hacked to remove the credits and alter the copyright back to "Mattel", pressing zero as for most INTV titles won't show the credits for this game but they are present in the code, the former titlecode is disabled and the date/title as well as start of game seems to me re-positioned (there is a very large unused block at start of the code). If there is some interest to revive the original credits i can see if i can achieve this. To tint the title black for this game gave me some headaches and i almost gave it up unless i made an error which leaded to what i liked to achieve, without this error i couldn't have made it.

 

Vectron:

 

The reason is a bit strange, the routine to tint the screen in a color depends on hierarchy and all games for which this routine is placed early in the titlecode will show this error. The fix itself is quite simple search a position roundabout 100 decles after the date entry this will work for MAME, sears (as far as the emulation let's me judge) and most of all for my hardware. Never mind that i re-positioned or altered the copyright it's just cosmetic. Also the hack itself is a cosmetic one and has no influence on the game (some changes i made for a different hack as just this cosmetic one).

 

 

For Vectron i altered the typing it won't show the grey letters in the setup screen and splatters the letters on the screen just like for the intermediate screen, further i added the possibility to change the amount of energy blocks and made it possible to speed up or slow down the game. I'm aware that "nobody" likes this game except me - i always loved it.

 

If interested you will find the altered configuration files in my blog "Intellivision Hacks" (after a cigi or two).

 

 

A little question pointed to "Zendocon" i applied your Vectron hack but the easter egg message "Marc Urbaniec sez watch your aim" won't appear at all or at least not after every level (however, maybe i will find out why). How i added the additional gfx for this game was a "first try of a different idea", usually i repeated the whole gfx cards section to add my smiley for this time i tried to move the new cards out in an unused section, it was only possible because the original gfx card block isn't to far from the end of the code and the rather large blank section, since it is only followed by sfx it would have been as well possible to outsource a sfx or two and use the new free space for the additional cards. Vectron opens now with the "energy block destroyed" sound but i listed all addresses for sfx and you can use the one you like most (or silence). To repeat the whole block would have been a treat the cards/mob section is very large for this game, very very large, it is large for "Thunder Castle" but Vectron uses easy about double of space for all gfx in the game. Yes for sure i made an altered title showing "YourSoft"...

 

 

For Thunder Castle i changed nothing except the cosmetic title screen hack the game is good as it is imho and i start to like it much. Perhaps i will update it to alter the amount of lives you have but on the other hand it seems fine to me.

 

For many games which i already posted in "Intellivision Hacks" i changed the copyright notice to the developer(s) (or part-wisely) to some i added a special title font for the title like this one;

 

 

maybe you have Battlestar but i have the font ;)

 

 

[Zendocon]

17 hours ago, Gernot said:

A little question pointed to "Zendocon" i applied your Vectron hack but the easter egg message "Marc Urbaniec sez watch your aim" won't appear at all or at least not after every level (however, maybe i will find out why).

I'm not entirely sure what went wrong at your end.  I know I added comments to indicate what the block of code was looking for before deciding to display the easter egg message.

 

There are a couple RAM addresses dedicated to the easter egg.  One stores the number you press at the "number of players" prompt and checks for a 9.  I think that is the last gate to pass through.  Another one increments after each level but also resets to 0, unless you move the Energy Block to an exact position during the end-of-level fanfare and press the correct key to begin the next level.  Before starting Level 8, the code checks this value in addition to the level number, as two additional gates to pass through.

[Gernot]

2 hours ago, Zendocon said:

I'm not entirely sure what went wrong at your end.

It just doesn't shows up, but i didn't played it emulated and dunno maybe it's caused by the PAL hardware?

I.e. the "screen color issue" respectively the wrong background color (even if that is caused by something very different and i still have no explanation for this behave, means why in all the world the position of the routine in the titlecode makes a difference to my PAL hardware? in general i assumed the routine on top after clearing the screen it is used often in this manner, then i moved it at the end all fine for the emulator just my hardware doesn't likes both of it, it expects the routine in a quite tight space around 100 decles after the date similar as when i use the sears exec in the emulator, often MAME itself shows the same issue no matter which exec i use, nonetheless if that works for MAME and for sears in jzIntv this is still no warranty that it will work on my hardware, i always need to check all three possibilities and for some i had to forgo sears if the issue stays, while unfortunately i can't tell how truthful this is the sears exec does not act the same in MAME and jzIntv).

 

Vectron is a game you can hardly play with anything else as the disc, a joystick won't suit to aim and fire.

However this would have been my next try to play it emulated and to see if there is a difference, sure i assume that it worked for you.

First assumed of course that i made an error but even if i use it standalone (means just this hack and nothing else) it won't work on my console.

Btw, it isn't important it just makes me curious, very curious. There would be still the possibility to splatter the sentence on the screen disregarding the conditions using an own addition.

 

[Zendocon]

7 minutes ago, Gernot said:

Btw, it isn't important it just makes me curious, very curious. There would be still the possibility to splatter the sentence on the screen disregarding the conditions using an own addition.

Given that the code before the text is a bunch of "gates" that bounce to the next level if any of several conditions aren't met, you can just poke values of 0x34 (NOP instruction) all throughout that block and disable all those "gates".  I think that's basically what I did.

[Gernot]

I haven't tried NOP yet but thought about yes, what i did yesterday is to pass all by similar to your hack with branch unconditional, but i didn't succeeded.

 

However, that was great hint (not the NOP but the whole thing) because i peeped right now into Joe's CP1600 summary (just for the proper meaning of "branch unconditional", i knew what it does but not what the single "B" stands for) and well it tells me a lot more as it did a couple of weeks ago, as i pointed it already out working with it made a lot of things clearer to me as when i have read it before it was all cryptic to me, step by step i understand the purposes. When i look now at this sheet it really clarifies some things i didn't understood before.

 

But i guess i have to play "nova blast" today, i promised a score even if it will be low.

[Gernot]

It seems my batteries are low this week i can hardly concentrate and i'm exhausted soon, must be the sign of autumn i assume it depresses me a little. Summer was to short this year in Switzerland, it is anyway but this year was really a bad year, already at start of July i said that i'm lucky to have a sunburn "at least i have a memory of the summer which have should been". I assumed such a weather, never ask me why these are predictions i made based on the color of my pee... Nah, some in a close valley to Glarus (Muotatal) say they ask the ants (and sit bare ass in an anthill) i don't but i watch all over the year the birds and i predict such because of this. This year i have seen a Stork in a very uncommon time in a very uncommon place (if that would have been in autumn or winter i wouldn't have wondered but not in summer), usually they don't fly into the valley they rest outside the valley close to a swamp, when they fly into the valley to search for food something is uncommon for sure. The early presence of "Alpendohlen" (Jackdaw) in the valley in summer also tells that something is wrong usually they are all over the summer high in the mountains and in September or October they will return, if i see them in July down in the valley it's obvious they leak of food. I even watched a pair of buzzard hunting in the the town this is even very uncommon they don't like high density areas, even if that looks amazing to see a buzzard hunting between buildings he isn't the bird who is built for such an energy intense way of hunting his manner is to lure in the sky as a typical predator. Based on all this i knew very soon that this summer will be rainy, cold and very short. But ants i never ask, what you can is to predict a storm if they start to get very busy and nervous pretty much a storm will raise up but for the all over weather situation birds will tell you far more. "Moutataler Wetterschmöcker" correct "Glarner Wetterschmöcker", lol.