Converting a NTSC 1200 to PAL

[rkauer]

Hello again ppl.

I'm bored to reboot my Amiga every time I want to play a PAL game (they are the majority of them).:sleep:

What is the pin I have to cut on Lisa chip to force the Miggy to PAL boot?:huh:

 Yes, I'll put a switch to choose PAL/NTSC.:-D

[alexh]

Sell your NTSC Amiga for loads of money to those nutter Americans who are always after them and get a Euro PAL one?

Use WHDload and change the tooltype to NTSC?

[Linchpin]

Agreed!

Normally the a1200 NTSC version goes for more than the pal... someone here will possibly buy it off you anyhows.

[James]

Any specific reason why NTSC machines go for more? I can't for the life of me figure out why someone would prefer an NTSC machine over a PAL one.

Both my 1200 and 600 are NTSC and I'd trade them any day for PAL units.

[edit]

Forgot to actually reply to the original question... Don't cut anything on Lisa!!!! It's Agnus you're after. Technically the difference between a NTSC and a PAL machine is pin41 on Agnus. When it is grounded, the unit defaults to NTSC when it boots. If you lift the pin and hook it to +5v with a 4.7k resistor, the unit defaults to PAL.

Now my disclaimer: I've done this countless times on A500's and it worked perfectly. I haven't tried it on my 1200 and 600 yet because of two reasons: one is that I'm waiting to have bought all the expansions I want for them before I heavily mod the hell out of them. The second and most important reason: I don't know *anybody* who made this mod on these two units...and I don't have cash to buy a second mobo if it does not work. This is probably due to the fact that people value these NTSC units so much....dunno.

[TjLaZer]

I think the reason the NTSC units sell for more is simply the supply/demand phenomena, and nothing else!  Most Americans were going to PCs when the A1200 came out so not as many were sold, etc.

[Zac67]

Pin 41 of Alice is controlled by R203 - if removed/cut _NTSC/PAL is switchable by the Sony video encoder U12.

The switching signal is output through pin 7 and inverted by Q201. PAL machines have additional components (crystal Y451 et al) to generate the color clock, maybe U12 checks for that signal. All this is not needed if you just use RGB output.

Hmm, with R209 in place (Rev 1B+), the U12 logic doesn't make much sense - it's simply not able to pull down _NTSC... If you just cut the R203 bridge, you should have PAL.

For complete PAL compatibility you need to replace the modulator (else you lack composite) and the crystal (else genlocking might be a problem), too.

[James]

Ok.. now explain that to me like I was a four year old.

[Speelgoedmannetje]

James wrote:
Ok.. now explain that to me like I was a four year old.

Open your miggy, and suddenly those numbers make kinda sense :-)

[Zac67]

I was just exploring the schematics - just disregard the second paragraph and it makes a lot more sense.  :-D

U12 (Sony chip) sits in the top left hand corner, a bit below that you find Q201 (three legged transistor) and to its left is R203 (black resistor) - looking at BBoAH photos it actually seems to be a real SMD resistor, not just a bridge. Can anyone verify that it shows '000' like my (bad quality) schematics state? Removing this or cutting one of the traces should make it a PAL Alice.

[willow]

Found this: at

http://wonkity.com/~wblock/a1200/a1200.html

.......

Q. Is there an internal jumper on the A1200 to set it to default to PAL or NTSC video?

A. No, but if you're really motivated, you can rig this up. My thanks to Tetsuo Oda and Byron Montgomerie, who provided the information that connecting pin 41 of the Alice custom chip to ground causes the A1200 to default to NTSC, while pulling this pin high (disconnecting it from the motherboard and connecting it to +5V through a 4.7k resistor) will make the default power-up state PAL. I would point out that making a modification like this on a surface-mount chip is difficult at best, and you may end up needing an expensive motherboard replacement, or, at worst, a dead A1200 that needs an expensive replacement motherboard available. In most cases, using the boot menu (obtained by pressing both mouse buttons on power-up or reset) to switch to PAL is sufficient. However, with some games, the hardware patch will be necessary to insure proper timing (changing to PAL via the boot menu might make a 50 Hz game run at 60 Hz timing, or vice versa).

I personally would be very interested in swapping motherboards from a PAL A600 for an NTSC A600 )

[jbuonacc]

why would someone in North America want a PAL unit? would it do me much good, or is it less of a difference than i think? my understanding is that it won't work with our tv's/monitors. is this wrong? how about power supply voltage? is a uk/euro computer any use to me over here without much modification? sorry if these are simple questions.

[da9000]

@jbuonacc:

dude, read the first post, you know, the one that started this thread:

the guy wants to play PAL games _properly_ (sound/timing wise)

Read the post before yours to see why doing the switch via software/boot menu won't be enough.

[James]

@willow
Don't go too far, I'll PM you on this

@jbuonacc
Someone in North America would want a PAL unit if said person wanted full compatibility with the software (99% euro) that's been released for the Amiga And yes, it is wrong to think out tv/monitors would not handle PAL. 99% of tv and tv-like monitors can handle the 10hz change without any problems whatsoever. As for power supply... a volt is worth the same in Europe as it is in North America. You can use an american power supply on a euro machine...same connector (on the mig side, not on the wall side obviously..although there are adapters for that)

There is absolutely no reason to us an NTSC unit (well.. that's my opinion anyways) because most software will run on both systems, the only difference is that with an NTSC machine running a PAL application, you are missing quite a chunk of graphics at the bottom of the screen, whereas an NSTC application fits completely in a PAL screen. Very few NSTC application will have problems on a PAL unit, the opposite is unfortunately not true. You can use a PAL unit right out of the box here in north america, no modding necessary. Hope this clarifies things a bit

[Agafaster]

...you'll only reaallllly get problems if you try to use overscan beyond 200 displaylines ...

[Zac67]

willow wrote:
... connecting pin 41 of the Alice custom chip to ground causes the A1200 to default to NTSC, while pulling this pin high (disconnecting it from the motherboard and connecting it to +5V through a 4.7k resistor) will make the default power-up state PAL.

No need for pullup though - Agnus/Alice has an internal pullup.