PAL Carts in an NTSC 7800 System

[Albert]

Can someone with experience tell me what happens when you try to play a PAL 7800 cartridge in an NTSC 7800 system?

 

Thanks,

 

..Al

[+Mitch]

Can someone with experience tell me what happens when you try to play a PAL 7800 cartridge in an NTSC 7800 system?

 

Thanks,

 

..Al

 

It depends if you are using the standard BIOS or one of the alternates. If you are using the standard Atari BIOS, it will hang on the Atari logo screen or go to a garbage screen.

 

If you are using the DevOS BIOS or the Asteroids BIOS in an NTSC 7800 the game will start but it may not play correctly. Some PAL games will hang at the title screen others will play but with severe graphics issues. Others will play with very little noticable difference to their NTSC counterpart. In other words, pretty much the same thing as if you tried to play an NTSC 7800 game in a PAL 7800 system.

 

Mitch

[Albert]

Can someone with experience tell me what happens when you try to play a PAL 7800 cartridge in an NTSC 7800 system?

 

Thanks,

 

..Al

 

It depends if you are using the standard BIOS or one of the alternates. If you are using the standard Atari BIOS, it will hang on the Atari logo screen or go to a garbage screen.

The system I'm testing on does not have the DevOS BIOS, so what I'm seeing is the Atari logo screen followed by a black screen. This is pretty consistent, I'm never seeing garbage or having it hang on the logo screen. I assume this behavior is dependent a bit on the actual game. I just wanted to confirm that this is what I should be expecting. I'm trying to track down a PAL system now that I can use to test some PAL 7800 games..

 

Thanks!

 

..Al

[HammR25]

Sounds like he's trying to test Space Duel and Asteroids Deluxe before shipping.

[Albert]

Sounds like he's trying to test Space Duel and Asteroids Deluxe before shipping.

 

..Al

[Eckhard Stolberg]

The system I'm testing on does not have the DevOS BIOS, so what I'm seeing is the Atari logo screen followed by a black screen. This is pretty consistent, I'm never seeing garbage or having it hang on the logo screen. I assume this behavior is dependent a bit on the actual game. I just wanted to confirm that this is what I should be expecting. I'm trying to track down a PAL system now that I can use to test some PAL 7800 games..

During the logo screen the NTSC 7800 among other things tests the signature key in the cartridge ROM. Since none of the PAL 7800 games have a valid signature key, the test fails and the BIOS locks the console in 2600 mode. Depending on what TIA registers the bit of 7800 game code accesses that gets executed in 2600 mode, you might get a black screen or some TIA garbage. So what you are experiencing with your PAL games is normal.

 

But if you are really testing homebrew games, you could just sign the ROM image, and the game should start on your console. But since a PAL game is setting up a display for 312 scanlines while the NTSC 7800 is only processing 262 of them, the game might not work properly as Mitch explained above.

 

 

Ciao, Eckhard Stolberg

[PacManPlus]

Hi Guys:

 

I apologize about this - Mimo, Mayhem and Gambler172 had tried the PAL roms on their systems and they worked fine.

The PAL roms actually are signed... Here is the batch file I used to make them:

 

type astdlx78.asm | sed -e "s/^;PAL//" > ADP.ASM
DASM ADP.asm -f3 -oASTDX78P.bin -lASTDX78P.lst
a78sign -f ASTDX78P.BIN
78HDR ASTDX78P.BIN ASTDX78P.A78 0000
del C:\TMP\ASTDX78P.zip
del ADP.ASM
pkzip C:\TMP\ASTDX78P.zip ASTDX78P.bin ASTDX78P.a78
prosystem -Region PAL ASTDX78P.bin

 

As I was telling Al in a PM, I sometimes would get caught with a black screen in emulation, because I would forget to change the system to PAL when testing the PAL rom. (That was before I used the command line option).

 

The thing is, literally *all* I did was add 50 to the number of scanlines for PAL versions.

Edited January 14, 2008 by PacManPlus

[Bruce Tomlin]

FYI, the built-in Asteroids in Euro consoles has PAL auto-detect in it somewhere. I know I disassembled it, but I can't find my commented disassembly right now. I think it just uses a DLI to count the number of scan lines. Then it uses DLLs with an extra 25 lines at the start and 25 lines at the end, and either sets it to point to the first 25 blank lines for PAL, or after the 25 blank lines for NTSC.

 

But an unsigned cartridge won't work at all on a regular NTSC 7800.

Edited January 13, 2008 by Bruce Tomlin

[Mayhem]

I apologize about this - Mimo and Gambler172 had tried the PAL roms on their systems and they worked fine.

 

Worked fine for me too on the CC2... always seem to get left out bah...!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[PacManPlus]

I'm sorry dude - that wasn't intentional... I fixed my above post

[ninermaniac]

I have three PAL 7800 games. I didn't know it until I put them in. They all went to the Atari logo then a blank black or vertical line screen appeared.

Edited January 17, 2008 by ninermaniac

[Albert]

I have three PAL 7800 games. I didn't know it until I put them in. They all went to the Atari logo then a blank black or vertical line screen appeared.

Thanks. Someone was kind enough to mail me a PAL 7800 system that I can use for short-term testing, but I'll need to get my hands on a system of my own at some point. I don't like sending out games if I'm not able to test them beforehand. Especially when the games are going overseas, where it's considerably more expensive to send out a replacement.

 

..Al

[ninermaniac]

You are lucky. I've got one rare 7800 game I can't do anything with. Mean 18 golf.

[Mayhem]

Erm, Mean 18 Golf on PAL is very common... so no loss there at least.

[thomasholzer]

I have three PAL 7800 games. I didn't know it until I put them in. They all went to the Atari logo then a blank black or vertical line screen appeared.

Thanks. Someone was kind enough to mail me a PAL 7800 system that I can use for short-term testing, but I'll need to get my hands on a system of my own at some point. I don't like sending out games if I'm not able to test them beforehand. Especially when the games are going overseas, where it's considerably more expensive to send out a replacement.

 

..Al

 

Getting a (cheap) PAL 7800 is no problem, but the postage from Europe to USA is really gone expensive in the last few years.

I did sent a PAL 7800 to Albert (AL Backiel) for testing some years ago. Maybe he doesn't need it any longer, and at least it's already in USA, so the P&P won't break the bank.

Edited January 17, 2008 by thomasholzer

[Albert]

Getting a (cheap) PAL 7800 is no problem, but the postage from Europe to USA is really gone expensive in the last few years.

I sent a PAL 7800 to Albert (AL Backiel) for testing some years ago. Maybe he doesn't need it any longer, and at least it's already in USA, so the P&P won't break the bank.

YAY US Dollar. I can ask Al if he still has it, thanks.

 

..Al

[+Mitch]

I did sent a PAL 7800 to Albert (AL Backiel) for testing some years ago. Maybe he doesn't need it any longer, and at least it's already in USA, so the P&P won't break the bank.

 

Is that the one he "blew up" when he was trying to test the PAL version of Impossible Mission?

 

Mitch