I recently purchased a nice A1200 complete in the case and a NTSC unit (which I wanted). The problem is that the mobo revision doesn't support Subway USB adapter I bought (the clock port is on the wrong side). I have another A1200 motherboard that is PAL and has the right clock port pins, but my question is, how can I make the PAL motherboard a NTSC one? Are there chips I can swap out? Traces I can cut or build?

Anybody have an idea?

Yeah I can always go back to doing that but I was hoping that I'd somehow be able to swap something and make it happen more easily. We'll see if anybody else has any ideas.

hmm, I'll be honest, I virtually never use mine in NTSC mode. A quick google search doesn't suggest anything.

THings that tweak how the machine boots goes in the startup-sequence stuff, but I think by the time you are that far in the boot process, its probably too late.

Im not a monster guru though.

Yeah I can always go back to doing that but I was hoping that I'd somehow be able to swap something and make it happen more easily. We'll see if anybody else has any ideas.

Is there a particular reason why you want a NTSC model?  Is it that you want to connect it to a regular TV?  If you can live with PAL and have a monitor with a VGA connector then look for one of those cheap RGB-VGA boxes that people use, rather than an expensive scan doubler.

Alice pin 41 controls whether it's ntsc/pal. A google search for "amiga alice pin 41" should give you an idea.
 
Obviously this just affects the refresh rate, the composite video output will be PAL60. So everything will look black and white in NTSC land.
 
The RGB video will be fine though.

Yup.

Ground Pin 41 of the Alice chip and the A1200 will boot it up in NTSC mode. If you enter the early startup menu you will see that the machine has defaulted to NTSC. Likewise with a NTSC machine if you lift Pin 41 from its solder point, thereby un-grounding it, the machine will boot to PAL mode. You could even install a toggle switch to control if the machine boots into PAL or NTSC mode. Just don't flip it while the machine is powered on otherwise Alice would probably be toast.



If you are using an RGB monitor everything will be perfectly fine. However the composite video and RF jacks will display incorrectly or black and white (results depends on the TV as some are more tolerant - especially older CRTs). Kipper2K recently posted directions for a full conversion which would make the composite and RF display correctly, but if you are using RGB I wouldn't bother. Full conversion involves a lot of component soldering and desoldering and expense.

Considering the composite and RF video out on them is crap anyways, this isn't much a lost. You could always purchase one of the NTSC/PAL Composite/S-video adapters from Amigamaniac that plugs into the RGB port. I had one and the s-video out is FANTASTIC. Very close to RGB quality. Kipper2k is also working on one that does component video as well.


HOWEVER - Might I ask WHY you want the machine in NTSC mode? Unless you plan on doing genlock video work or hooking it up to a regular TV or similiar, I personally see no need for NTSC. Almost all the good software and certainly nearly all games are in PAL. I like many have been using PAL Amiga's here in the states for years and have been a lot happier with it. More compatible and software runs and plays the way it should. No more speed up music or missing parts of the screen like you normally get with NTSC machines trying to run PAL software. All those excellent Demo's from Europe would play perfectly unlike on NTSC machines. So unless you have a mountain of NTSC software or some other burning desire I wouldn't worry about it.


Also, in case you aren't aware, if you are using an RGB monitor like the 1084, it will display just fine with the PAL A1200. The RGB inputs on them will display both NTSC and PAL fine. Likewise with many (most?) other RGB monitors. I use a JVC broadcast quality monitor via RGB and works fine with both 50 and 60Hz inputs.



Bottom line - If using an RGB monitor, ground Pin 41 of the Alice chip to force the machine into NTSC mode if you really need it. Otherwise hold down both mouse buttons at bootup and switch to NTSC via the early startup screen.

Your games might be pal, but the majority of Killergorilla's collection is the ntsc version.

You don't honestly believe this do you?



I sincerely doubt that a UK user would base his WHDLoad collection off NTSC versions of games. Especially considering most all the installs are from Euro folks based off Tosec dumps. Which originated in Euro land anyways. I know there are a couple NTSC specific releases in it.


Now, some NTSC games that were took over to PAL territories were never rewritten by some lazy devs and probably have some issues. But none the less those were PAL releases. Plus most of the big games released for the Amiga were out of the UK anyways.


You are insane if you think his collection is based off NTSC games.


Never mind the fact all the demo scene productions are most certainly PAL only. Some might kinda work on NTSC, but still PAL is the best way to enjoy them.

Just don't flip it while the machine is powered on otherwise Alice would probably be toast.

I seriously doubt that.
Though I can't truly vouch for Alice (never owned an AGA machine) Agnus doesn't care at all if the switch is flipped 'hot' (used to do that on a 500 and a 3000). Since Alice is more-or-less just a newer rev of Agnus it shouldn't be more picky.

I am in San Jose, CA USA. Actually I'd like to get another Indivision when one crops up but given I live in the States all my games and software are NTSC versions and it's always been a pain for me. Not to mention I hate the flicker of a 50Hz resolution. I can swap at boot but doing that all the time is also a pain.