Questions about PAL/NTSC compatibility in Amiga games

[arkpandora]

Hi,

A discussion with another member has raised in me the following questions about PAL/NTSC differences in Amiga games :

1. Will any PAL game run on an NTSC Amiga and vice versa ?

2. Which kind of issues may arise ?

Perfect Amiga animation is synchronized with the screen's refresh rate, so :

3. Does it mean that PAL and NTSC animations are coded differently, or will the same version simply play at a different frame rate depending on whether it runs on a PAL or NTSC machine ?

4. If they have different code, does it mean that one version may have perfect animation on the video standard it was designed for, and horrible animation on the other, like when you emulate a 50 Hz PAL Amiga on a 60 Hz VGA screen mode ?

Thank you in advance for enlightening the lost me.

[Amithony]

arkpandora wrote:
Hi,

A discussion with another member has raised in me the following questions about PAL/NTSC differences in Amiga games :

1. Will any PAL game run on an NTSC Amiga and vice versa ?

2. Which kind of issues may arise ?

Perfect Amiga animation is synchronized with the screen's refresh rate, so :

3. Does it mean that PAL and NTSC animations are coded differently, or will the same version simply play at a different frame rate depending on whether it runs on a PAL or NTSC machine ?

4. If they have different code, does it mean that one version may have perfect animation on the video standard it was designed for, and horrible animation on the other, like when you emulate a 50 Hz PAL Amiga on a 60 Hz VGA screen mode ?

Thank you in advance for enlightening the lost me.

Hi there, the games should work the same on either platform as the handling is not done by the code, but the graphics hardware/motherboard/screen combination. NTSC and PAL are different screen standards used in different parts of the world, but the underlying software remains the same. Otherwise, you would have seen "PAL Version" or "NTSC version" stamped on software as you go to buy them.

[arkpandora]

Hi there,

Many thanks for your reply.

Then how can the same game give perfect animation both on a 50 Hz PAL screen and on a 60 Hz NTSC screen, as such a quality requires synchronization between the frame rate (hence the code) and the screen refresh rate ?  Is the game played at a different speed ?  But this would lead to some - at least sound synchronization - issues I suppose.

[Damion]

There definitely were both PAL and NTSC versions of most games. PAL games will run too quickly (messed up timing) if run on an NTSC machine, unless it's first switched to PAL mode. (I've found there are some games and demos that will simply refuse to run in NTSC mode.) In addition, there can definitely be sound and graphics issues running PAL software in NTSC mode (at least, I've never tried the reverse but I imagine the same problems can arise).

[arkpandora]

Thanks -D-.

Then it would be clearer.

In addition, I suppose that games that use the additional lines of PAL cannot be displayed properly in NTSC either.


The good thing with this hour of the night in Europe, is that you only find NTSC users on Amiga.org...

[Damion]

Exactly, part of the screen will be cut off.

As an aside, I remember buying a 1 meg Agnus for my A500 back in the day, so I could convert the trapdoor RAM to "chipram" and run PAL software... only to discover that my mobo was a Rev 6 and already had it, DOH! :crazy:

[arkpandora]

You'll lose me easily again.  Why would you have needed extra Chip RAM in order to run PAL software ?

[Damion]

Hey arkpandora,

arkpandora wrote:
You'll lose me easily again.  Why would you have needed extra Chip RAM in order to run PAL software ?

Basically, the 512k Agnus' were region specific, PAL or NTSC only. Those with Rev 5 boards would upgrade to an NTSC 1 MB Agnus, configure (small mobo modifications) the trapdoor card as CHIPMEM, then switching to PAL would be possible.

As I had a Rev 6 board, the 1 MB Agnus was already present. However, it still wouldn't switch into PAL mode until the board modification was done (which would allocate the 512k fast (slow) mem as chipmem).

Damion

[rkauer]

 This is valid only for A500 with version over 5.

 For other Amigas, there is just a resistor (zero Ohm) in the pin 41 of Agnus (A2000 & 3000) or the equivalent Alice in AGA Amigas (same pin, BTW).

 For NTSC operation, this pin must be wired to Vcc via a 10000 Ohms resistor. For PAL, wire it to ground directly.

[arkpandora]

OK - thanks for these informations.

[Phantom]

I tried recently Defender of the Crown CDTV (NTSC) on my PAL CDTV. It works.

Well... it didn't mention anything about NTSC or PAL on the cover, even if I bought it from US. I think that all games are one region only.

[arkpandora]

Does it work accurately ?  Then would it mean that the CDTV is both PAL and NTSC compatible without any hardware change ?

[Phantom]

It worked normally, like a PAL game. I think that CDTV can play both PAL and NTSC games. I don't know the opposite (NTSC CDTV with PAL games though).

[SamuraiCrow]

The composite signals are different on PAL from NTSC.  If you have an adapter that plugs into the RGB connector directly like an old Amiga 520 RF Modulator it will work correclty.  AGA will switch between NTSC and PAL modes properly, however.

[arkpandora]

I think that CDTV can play both PAL and NTSC games.

Does it mean that a PAL CDTV can also display NTSC, or that the game has both PAL and NTSC code ?  Does your monitor/TV display the game in NTSC ?


@SamuraiCrow

Do you mean that the composite signal on a non-AGA Amiga is bound to only one standard even if the computer can display both ?