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Gallospacca

Convert ntsc rom to pal 60 and pal 50?

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Hi, about a year ago I started using my Atari 2600 jr again. and I'm having a lot of fun.

 

Thanks to the Uno cart I have tried many homebrews and they are all fun, especially the 2 player ones.

 

The problem is that many of these games have been released only in ntsc version but my console / tv are not able to play them, not only that but often not even some pal 60s work (only happens with homebrews) so I would need the pal 50 version for each one.

 

For those who would have liked to play the most (First of all Palomino) I tried to write a message to the developers asking for a version pal 50 but no one ever answered me.

 

So I thought: is it possible that it is so complicated to convert such tiny and archaic files? Isn't there a simple software where to insert the rom, choose the format you want and convert the rom in a second? I don't know anything about programming or anything like that but I think it would be possible for some expert to make such a software ... this would solve all my problems and would also be useful for anyone who wants to play some exclusive ntsc or pal on his Atari.

 

Let me know if by any chance there is something like this or if any of you would be able to make it happen. Or if there is someone among you who can '' easily '' convert some games for me .... in that case I will prepare a list.

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9 minutes ago, Gallospacca said:

So I thought: is it possible that it is so complicated to convert such tiny and archaic files? Isn't there a simple software where to insert the rom, choose the format you want and convert the rom in a second?

For the color conversion from NTSC -> PAL, it can get a bit complicated depending on how colors are loaded and where they are stored.  A simple software solution would only be able to handle simple cases.  More complicated cases require analysis of the ROM which would take a lot of time to develop.  It's quicker and easier for a human to disassemble and attempt to analyze the code, then to write code to analyze the code.  The easiest option would be to contact the original developers to ask them about it.

 

A Pal60 -> Pal50 conversion involves digging thru the code to figure out how to change the speed of the game objects.  That may be simple and easy to do, or it may be complicated depending on how the developer designed it.

 

With that said, I believe there is ROM hacking software somewhere that would assist in converting colors, but it would still be a lot of manual work.

 

@Nukey Shay is one of the guys to talk to about hacking ROMS.

 

----

 

As for Palomino, the developer keeps to himself.  No one has been able to contact him.

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Thanks for the answer, I understand .. so it's not that simple, it's a real shame because for me only a small part of homebrews work properly.

 

In this regard I would like to point out that this thing is a little annoying, I understand that Atari is an American brand and that therefore it is there that most of the fans are, but it would be right that when someone makes a game make sure to also release the pal 60 and pal 50 versions, if I were able to program a game I would do it to make sure anyone from anywhere in the world can enjoy it.

 

As it stands now it gives an impression of the type ''who cares about the rest of the world'' So if any of the homebrew developers read this message please also make these versions for your new or old software.

 

This is not meant to be a negative criticism, indeed I thank all those who still do their utmost to keep this fantastic console alive, in many cases these software are even superior to most of the original titles.

 

Some examples that I have been able to play and that still amuse me so much: Amoeba jump, Blinky, Chetiry, Climber 5, Fall down, Crazy balloon, Go fish !, Ixion, Jsumo, LEM, Pac-man 4k, Pitkat (I have the original for Gameboy and seeing such a faithful conversion running on the Atari 2600 is incredible), they are all little masterpieces.

 

Unfortunately many others that I would love to play do not work properly: Bird and beans (mythical pyoro from Warioware games), Eggventure, Gingerbread man, Jammed, Palomino, Juno1, Lead 8k, Monkey king, Peril, Ninjish guy, Princess rescue, Seaweed assault, Slideboy , Thrust, Snow flakes, Shower scene, Rc sumobots.

 

I've seen gameplay of these on youtube and they all look really fun, unfortunately I've tried all the various releases and versions that I have found but none work for me, I would love to be able to play them so if anyone has the pal 50 versions or can convert them for me (and for everyone else who has the same problem as me) , I would be infinitely grateful.

 

Greetings from Italy

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My first game was released as NTSC and PAL 50, though after some "complaints" I released a PAL60 version and have only done PAL60 since.

 

Odds of getting everyone to also release PAL50 is slime to none, your best results would be to find a different TV that supports PAL60 as the TV is the limiting factor.

 

 

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Thanks for the reply.

 

I have many TVs at home, I have tried them all, with some you see only in black and white, with others you see all the wrong colors, with others you see the whole distorted image, so obviously I'm using the only one that allows me to see all the original games in the best way, and even the homebrews, except that some do not work properly in the pal 60 version, while the pal 50 does not give me any problems.

 

I have 8 TVs at home between old crt and more modern lcd, so I cannot and do not want to buy more at random in the hope of solving, if it is possible that the developers also make a pal 50 version or if someone is able to help me by converting some games to pal 50 it would be great, otherwise I will simply not play the games I have listed and all the others not available in pal 50.

 

Another solution (perhaps) would be to buy an American Atari 2600, but honestly I like to use my original console which I have had for over 30 years and which luckily still works great.

 

Only one thing is not clear to me, in the original cartridges or in the roms of the original games there are no pal 50 or pal 60 versions, it just needs to be pal and everything works perfectly, so why is there this distinction with homebrews? can't you just make games that work with both pal 50 and pal 60 as the originals?

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2 hours ago, Gallospacca said:

Only one thing is not clear to me, in the original cartridges or in the roms of the original games there are no pal 50 or pal 60 versions, it just needs to be pal and everything works perfectly, so why is there this distinction with homebrews? can't you just make games that work with both pal 50 and pal 60 as the originals?


With most systems the video chip in the console controls the number of scanlines sent to the TV.  For the Atari the game code itself controls that.  For NTSC it should output 262 scanlines per frame, for PAL and SECAM it should output 312. As seen here, games for the 2600 output a wide range of scanlines, which wasn't an issue as the majority of analog TVs didn't have a problem with that. Modern TVs on the other hand...


There are 3 versions of the 2600, Atari NTSC vs PAL vs SECAM. The main difference between the 3 is that each has a different color palette.  If you want to draw a green tree you could use the value $C2 for NTSC, $52 for PAL, or $08 for SECAM. Those numbers are in hexadecimal, if expressed as decimal those values are 194, 82, and 8.

A PAL60 game is just an NTSC game that's using color values for a PAL console. Changing color values is simple, just put something like this in your code to define color constants:

 

 IF COMPILE_VERSION = NTSC
 ; NTSC color values
GREY            = $00
YELLOW          = $10
ORANGE          = $20
RED             = $40
PURPLE          = $60
BLUE            = $80
CYAN            = $B0
GREEN           = $C0
WHITE           = $0F
 ELSE
 ; PAL color values
GREY            = $00
YELLOW          = $20
ORANGE          = $40
RED             = $60
PURPLE          = $C0
BLUE            = $D0
CYAN            = $70
GREEN           = $50
WHITE           = $0F
 ENDIF


Then use those constants like this:

StartColor:
    .byte RED, RED + 8
    .byte RED, RED + 10
    .byte RED, RED + 12
    .byte RED, RED + 14
    .byte RED, RED + 12
    .byte RED, RED + 10
    .byte RED, RED + 8

MenuOptionTE:
    .byte GREEN + 8, BLUE + 8
    .byte GREEN +10, BLUE +10
    .byte GREEN +12, BLUE +12
    .byte GREEN +14, BLUE +14
    .byte GREEN +12, BLUE +12
    .byte GREEN +10, BLUE +10
    .byte GREEN + 8, BLUE + 8


The + # specifies the luminosity (brightness) of the color.

 

Changing the scanline counts is more involved, especially if you want the game to play the same.  If you just change the scanlines without anything else then an item moving 1 pixel per frame moves at 60 pixels per second on an NTSC console but only 50 pixels per second on a PAL console.  That would make the game quite a bit easier to play. In fact I specifically added a PAL60 option to my hack of Kaboom! as Activision didn't compensate for the speed difference when they ported it to PAL back in the day and many PAL gamers prefer the faster speed of the original NTSC version.  Kaboom! Deluxe! adds the Pitch and Catch variation from the Atari 5200, plus some graphical enhancements over the original. It's available as NTSC, PAL, and PAL60.


Over time the community's gone to the point were the added effort for PAL hasn't been worth it - just like my first game supported PAL, but since then I've only done PAL60. A number of the PAL60 games you listed as troublesome were even created by people in Europe.

 

Do you happen to have a VCR?  I've seen numerous references to people here putting a VCR between their TV and Atari to resolve video issues.

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On 7/22/2021 at 9:40 AM, Gallospacca said:

As it stands now it gives an impression of the type ''who cares about the rest of the world'' So if any of the homebrew developers read this message please also make these versions for your new or old software.

 

This is not meant to be a negative criticism, indeed I thank all those who still do their utmost to keep this fantastic console alive, in many cases these software are even superior to most of the original titles.

As an "old" homebrew author, I prefer to build with PAL50 in mind. I like the control fractional positioning provides. Ideally, I'd like to truly consider PAL50 with the increased vertical resolution (instead of fitting a smaller NTSC frame within a PAL50 frame) and sound changes. Those would take more effort but would make for a better end result, IMO. There were some titles in the 80s that did this. Air-Sea Battle and Video Pinball come to mind.

 

There have been a couple of threads here on AA about this subject. I believe the majority of those in the PAL regions answering the poll didn't mind PAL60 releases because the majority of their televisions supported it. I believe these results combined with the sale comparisons between PAL50 and PAL60 in the AA store probably drove authors to not take the extra effort to do PAL50 releases.

 

Thank you for your post and feedback. I welcome it. It helps to make our products better for everyone.

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I think instances of people not being able to play PAL60 games have been relatively rare. That combined with the fact that more users seem to prefer PAL60 versions of games and the much-simpler process of doing a PAL60 conversion are reasons that I choose this format for games vs standard PAL.

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I've had people reject PAL60 builds because their older PAL TV just leaves static white noise at the bottom where the PAL60 graphic kernel stops drawing.

 

But, yeah.  I wish everyone would just let me make PAL60 games since I haven't found any auto detect code for region differences. 😛

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Is there a downside to drawing in PAL50? I understand that it may be much easier to produce a PAL60 port in many cases, but supposing all other things were equal, is there any reason not to use PAL50 (eg, is it incompatible with newer TVs or something)?

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3 hours ago, DEBRO said:

and sound changes

 

I hadn't considered that - that means my sound effects in Medieval Mayhem are stretched out longer for PAL players.

 

2 hours ago, Gemintronic said:

since I haven't found any auto detect code for region differences. 😛

 

I think you're being facetious as you're a member of the Harmony/Melody Club, but I'm adding this in case others were unaware of the Console Detection routines we have.

 

The 2600 / 7800 Detection works with any cartridge. The 2600's TV TYPE switch and the 7800's PAUSE button are wired to the same bit in SWCHB, but work differently (2600 = toggle switch, 7800 = momentary button) so knowing which console the code is running on lets you handle either correctly.

 

The NTSC / PAL / SECAM Detection requires a clock in the cartridge. This takes advantage of the fact that each region's console has a slightly different clock rate:

  • 1.193182 MHz for NTSC
  • 1.187500 MHz for SECAM
  • 1.182298 MHz for PAL

Because of this the time it takes to drawn a set number of scanlines will be slightly different. Using the 70 MHz clock on a Harmony/Melody, the clock will tick about this number of times after drawing 262 scanlines:

  • 1,168,169 for NTSC
  • 1,173,759 for SECAM
  • 1,178,923 for PAL

 

We figured this out while I was developing Draconian, and I use it to automatically select which color palette to use.  While I only change the color values in Draconian, a game could have logic to output 312 scanlines if SECAM or PAL were detected.

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@SpiceWare

 

Naw, not being clever.  Due to poor research and worse assembly skills I have failed to find a snippet of code that (without an ARM chip or Melody board) reports if the system is running PAL or NTSC.

 

Ideally I could take a plain old 32k ROM board and run PAL/NTSC detection code at startup.  Put the results into a memory area that corresponds to a batari BASIC variable and let the canned kernel carry on.

 

Unfortunately, not everyone that offers to publish my games uses Melody boards.  That being said I'm only assuming the routines to mentioned are only Harmony/Melody specific.  Definitely need to do more research!

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I'm not aware of any solution that works without a Harmony/Melody, though similar code should work on the UNO Cart.

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Posted (edited)
On 7/24/2021 at 7:29 PM, [email protected]tar-hope.org said:

Is there a downside to drawing in PAL50? I understand that it may be much easier to produce a PAL60 port in many cases, but supposing all other things were equal, is there any reason not to use PAL50 (eg, is it incompatible with newer TVs or something)?

There are pros and cons. E.g. flicker becomes worse but you can display more detail in PAL50. 

 

Also many developers use(d) frame driven code, because it is easier to implement and usually saves valuable RAM, ROM and CPU time. I created an alternative, which doesn't use more RAM, but AFAIK no one besides me has used it yet.

Edited by Thomas Jentzsch

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What an interesting discussion was born here!

 

I didn't think my problem could arouse so much interest.

 

Anyway I looked for something on those VCRs that Spiceware kindly recommended me, but honestly I don't understand much .... there are tiny and inexpensive ones, or huge and very expensive ones, and honestly the idea of spending money without having the certainty of solving does not appeal to me very much.

 

In the end my atari works perfectly with all the original games and with some of the homebrews so it doesn't seem convenient to me to spend money to run a handful of games that don't work for me, although obviously they are very interesting games that I would gladly play, so I renew the my request: if someone is able to help me by converting some games into pal 50 or if someone has in mind a software or a '' trick '' to convert them easily I would be really happy, the games I have listed start normally and you can also hear the sound correctly, you can even play and hear the reactions to key presses, but the image is a series of distorted and incomprehensible horizontal lines, I am attaching a sample photo.

 

I had recommended the idea (apparently unattainable) of a software to convert games in order to be '' independent '', let me explain: let's say that now someone converts for me those games that do not work for me or that even all the developers make a pal 50 version for me ..... sooner or later I will need it again and asking for help every time is not pleasant, in the end I would become annoying.

 

With a software that can somehow convert the format of the game everyone could convert the games that interest them without having to recommend themselves to anyone, but apparently as Spiceware explained to me it is not so easy to make such a software and perhaps it would not work always correctly .... mine was just a naive idea dictated by my total ignorance in programming.

 

Anyway thanks to everyone for the answers and thanks again to all the programmers who make such fun games for one of my favorite consoles (。 • ̀ᴗ-) ✧

IMG_20210726_205235.jpg

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Posted (edited)

You can buy almost any dead cheap VCR or TV. I wonder what kind of TV you have that it doesn't support PAL60. Almost all PAL TVs support PAL60. And today CRTs and VCRs are dead cheap. 

 

Therefore converting games to PAL50 will most likely never happen. PAL60 is much easier and the result is better.

Edited by Thomas Jentzsch

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For the few games that don't work on real hardware, you still have the option of using an emulator.
Maybe a different experience than real hardware but at least you can play the games.

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What game is that in your screenshot? Is that what a NTSC game looks like on a PAL50 display? Guess I wouldn't have expected it to look like that.

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I think your best option is to RGB mod your 2600Jr. I carried out the mod for exactly the reasons you've listed. The RGB mod not only allows you to switch between NTSC and PAL colour pallets, effectively making your console multi region, but if you connect via RGB you'll be bypassing the NTSC colour signal which results in black and white on some TVs. Assuming you live in a European country most/all TVs have a scart connector which accepts 60Hz RGB.

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How poor are your assembly skills?  I've never done a PAL conversion, but this doesn't seem like it would be too difficult in many cases, having such a limited scope with a known goal.  Perhaps you could do this yourself.

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