Booting

[jviper]

I notice that when I hold the left and right mouse buttons down while booting, the boot options page comes up. But when I change the screenmode from PAL to NTSC, it doesn't switch to NTSC unless I have the NTSC checkbox checked. Is there a way I can make the Boot options thing actually have an effect, or is it disabled because I'm running it in WinUAE?

[thomas]

The default NTSC or PAL is set on WinUAE's chipset page. This corresponds to the PAL/NTSC jumper on the Amiga's motherboard. In the early startup menu you can switch the current display from PAL to NTSC and vice versa by pressing a key. This only affects the menu, it has no effect to the screen mode the Workbench uses. Finally you can change the default from PAL to NTSC by setting the NTSC checkbox. This affects the boot screen mode and graphics clock as if you set NTSC in WinUAE's chipset, but only for the current session. And it does not change the screen mode set up in the Workbench prefs (loaded by IPrefs in Startup-Sequence). Use Prefs/Screenmode to change the Workbench screen mode.

[alexh]

This corresponds to the PAL/NTSC jumper on the Amiga's motherboard

Is that Entirely [edit] true? I dont think it is.

[thomas]

What do you think ?

[alexh]

I guess it is sort of true. The hardware man in me is coming out. With the Agnus research I did.

It's the Agnus chip (in OCS/ECS Amiga's) that determines PAL or NTSC capability.

The jumper you speak of didnt exist on early Amiga's because the early versions of Agnus were hard wired to either PAL or NTSC. Your only option is to use a different chip.

Later A500 versions can be changed to NTSC or PAL by a jumper / pin on the Agnus.

From revision 8372 the jumper/pin selected which mode you booted up in, but they added a register bit to allow you to switch between PAL or NTSC at runtime.

Before they did this, whatever mode you selected via the jumper would be the mode the Amiga would run in all the time.

After they added the register the result was regardless of the position of the jumper software could switch to whatever the mode they liked. The result was you couldnt force games to be NTSC if they were programmed to be PAL and vice versa.

[jviper]

Ok.....I am in Workbench:Prefs/ScreenMode. I wish to add a display mode. Do I do that here, or somewhere else? Is it possible?

[alexh]

Thomas can you answer this? I cannot work it out.

Why there are PAL and NTSC part numbers for Agnuses after they introduced this jumper? Do you know? They definately did have different versions for PAL and NTSC for 8375 parts.

I *THINK* that a PAL 8375 (318069-10) sees the jumper off as PAL.

And an NTSC 8375 (318069-11) sees the jumper off as NTSC.

But it makes no sense, surely it would be cheaper to just jumper all NTSC motherboards rather than run two chip lines?

[jviper]

Well, I found out somthing I didn't know was going to happen before:
Go into WorkBench:Storage/Moniters, and copyall of the monitor mode thingies into WorkBench:Wbstartup (in my case, there was like, 10 of them). Then reboot. Now go into WorkBench:Prefs:Screenmodes, and see all the display modes that show up there .

All those display modes also showed up when I started DPIV, as well

[thomas]

@alexh:

It seems you have more knowledge about the hardware than I :-)

I could imagine there are still different chips for NTSC and PAL *machines*. Actually it are no NTSC and PAL machines but American and European machines. American are 110V / 60Hz / NTSC and European are 220V / 50Hz / PAL. So setting the jumper changes the display mode from NTSC to PAL or vice versa, but the power supply is still the same and the power frequency is still 60Hz resp. 50Hz. Perhaps the Agnus chip has to consider this.

@jviper:

Ok.....I am in Workbench:Prefs/ScreenMode. I wish to add a display mode. Do I do that here, or somewhere else? Is it possible?

To add more display modes you have to run more monitor drivers. Monitor drivers usually are stored in Sys:Storage/Monitors. You can temporarily activate a monitor driver by just running it from there. In order to run it automaitcally at boot time, move it to Sys:Devs/Monitors.

However, on WinUAE most monitor drivers don't work although WinUAE claims to emulate AGA. IIRC only PAL and NTSC drivers work, all other drivers don't have any effect.

If you have installed Picasso96 for graphics card support, there is only one monitor driver for the graphics card (UAEGFX). To add more screen modes, on a real Amiga you have to edit them with Picasso96Mode. On WinUAE the UAEGFX driver just copies what Windows offers, so to add more Picasso96 modes to WinUAE, you have to add them to Windows.

[Toni Wilen]

Originally Posted by thomas

However, on WinUAE most monitor drivers don't work although WinUAE claims to emulate AGA. IIRC only PAL and NTSC drivers work, all other drivers don't have any effect.

They do "work" since 1.1*. Most look quite weird but they do work

* if "Genlock connected" is unticked, most non-video frequency monitor drivers won't be available if genlock is connected and Kickstart always detected connected genlock until 1.1.