A couple of games with display, gfx issues on real 2600 Jr. PAL

[maiki]

Alien 8k was a bad choice I think. I have discovered a different sort of bug in the Alien 8k hack. And that is related to reading joystick. In the second level where you move up and down, after you have completed the maze, it takes some time before the player responds to joystick controls. This happens in the Alien 8k and not in the original Alien 4k. So it looks like the person who did that 8k hack did manage to screw a few things up... Never mind!

[Omegamatrix]

Alien 8k was a bad choice I think. I have discovered a different sort of bug in the Alien 8k hack. And that is related to reading joystick. In the second level where you move up and down, after you have completed the maze, it takes some time before the player responds to joystick controls. This happens in the Alien 8k and not in the original Alien 4k. So it looks like the person who did that 8k hack did manage to screw a few things up... Never mind!

.

It is really easy to mess up a rom when hacking, believe me on this! I've done so many times ha ha. I can assure you Nukey is the best there is at hacking. He is a notch above everyone else. Just like Highlander... there can only be one. Nukey takes a rom and molds it with pure creative goodness. You can tell a Nukey Shay rom when it just smacks you as being awesome and fun.

 

 

That being said I'm not even sure if he operated on the final version of this rom. I hunted high and low for it, and only could find where he started it in 2006. This rom says 2010. With the scanline jumps, I can see Nukey not knowing as he doesn't have an Atari and does everything in emulation.

 

 

I believe I have now found and patched the rom so that you can move up on the 2nd level. I haven't passed this level, so It does need testing:

 

Alien8k(Pal60fixV4).bin

[maiki]

Perfect.

[maiki]

Another one with graphics issues (probably later Jr. related) - this time it is the very recent Space Raid by Nanochess. I have only run the PAL version so far. Will post image soon. This should perhaps be posted to his own Space Raid thread.

 

Forget about this one. I had different version of the game in Harmony opposed to Stella. He later changed the background dots in the 1st level. They are all 100%.

Edited November 4, 2013 by maiki

[Thorsten Günther]

I also encountered a PAL game with sync issues: Lock 'n Chase by Telegames

[+nanochess]

Another one with graphics issues (probably later Jr. related) - this time it is the very recent Space Raid by Nanochess. I have only run the PAL version so far. Will post image soon. This should perhaps be posted to his own Space Raid thread.

 

Forget about this one. I had different version of the game in Harmony opposed to Stella. He later changed the background dots in the 1st level. They are all 100%.

 

I was just about to suggest you to test it

 

BTW, there is a small scanline change that I'm solving. So in PAL from time on time, one frame could be black&white.

Edited November 4, 2013 by nanochess

[+SpiceWare]

There have been a number of variations to the TIA chip, not all are 100% compatible with each other. 2600 Connections has a page which documents the variations and the known problems.

[maiki]

 

I was just about to suggest you to test it

 

BTW, there is a small scanline change that I'm solving. So in PAL from time on time, one frame could be black&white.

 

I have noticed that. I think in the second level, on the blue background the upper portion of the screen had a slight color flicker. It was the PAL version. Right now I am using the PAL 60 4k version and I am just happy. Your game is really good.

[maiki]

I also encountered a PAL game with sync issues: Lock 'n Chase by Telegames

 

These is possibly a slight sync issue before the maze appears but displays just fine on my TV.

[maiki]

There have been a number of variations to the TIA chip, not all are 100% compatible with each other. 2600 Connections has a page which documents the variations and the known problems.

 

Thank you. That is great info.

 

So, I have a version 10 then.

 

"Version 10 is found in 2600 "JR" consoles (both NTSC and PAL) that are made in China after late 1989. The signal timing in the TIA for the shifting pulses for the movable objects seems to be a little off from older versions of the TIA. Therefore when a game starts the shifting process in such a way that some of the shifting pulses happen during the visible part of the screen, the movable objects might be positioned slightly differently. This affects all PAL 7800 consoles too"

 

[+nanochess]

Here is a list I've found while investigating for Space Raid, all games severely deviating from standard scanlines will show sync problems

 

http://www.digitpress.com/library/techdocs/vcs_scanlines.htm

 

I've the Asteroids of 265 lines, the frame desyncs every few seconds.

[maiki]

OK, another game with problems: Treasure Below (Video Gems).

 

The game boots up but nothing moves (the cloud, player, enemies, playfield - opposite to Stella). The enemies are being animated though. SELECT seems to be read, but pressing fire on the controller or RESET does not start the game.

 

so it's kinda frozen on the real console

 

http://www.atarimania.com/game-atari-2600-vcs-treasure-below_11807.html

 

 

[Omegamatrix]

I took a quick look, and this game uses the right difficulty switch as a pause switch. Toggle it to the position 'A' (pro) and it will un-pause.

 

 

It's a poor design to have a game freeze upon start-up like this. You don't want the first impression to be a sense of frustration or confusion. What the programmer should have done in this case is default "un-paused" to the position the switch lies in at power-on. This has been done in the past using the color/bw switch as a pause switch. Other good things the programmer can do is allow the fire-button to un-pause the game, reset to still function, etc... At least one quality up-coming homebrew is programmed with these user friendly features.

[maiki]

Not a game this time but I have come across this good 32k demo "Ataventure" (https://www.pouet.net/prod.php?which=62139). Not sure if that is related just to later TIA, but they already know about the issues (see the comments on that page).

[Dionoid]

FYI: the cartridge "Fatal Run" is known to have problems running on a PAL 2600 Jr.

 

I can run the game on my Darth Vader and Light Sixer without problems, but it only shows a black screen on both my Pal 2600 Jr's from China. I think that is because of a newer version of the TIA in those late Jr machines from China.

 

--Dion

[Jstick]

Apologies for bumping an old topic, I noticed @Omegamatrix posted a fix for Spider Fighter PAL earlier in the thread and I’m looking for an NTSC version of the same fix (if one exists). I’m seeing the same graphics corruption in the game on my NTSC Jr.