Amiga 3000 conversion from NTSC to PAL

[StompinSteve]

Hello,

I've found a North American Amiga 3000/25 on AmiBay in perfect nick ***and*** this time...... I was the first person to respond to the auction. Yeeeeeeh after all those years, my dream is finally coming true.
It has a Rev 9.1 Motherboard and a Rev 7 super buster. I already ordered a Rev 11.
It has 2 MB Chip and 8 MB Fast.

It will need to be converted to PAL. I read conflicting advice. Some say I need to swap an oscillator for a 50Hz one. But others say I need to simply set Jumper J200 from NTSC to PAL. This being a Rev9 board, I believe the latter is true. Can anyone confirm?

If the above is true, then all i'll need to do otherwise is to find a 230V (European) Powersupply. That's not gonna be easy...

Am I missing anything? I've googled and googled but all I ever read is about converting European A3000's to North America spec. Have not found anything about the other way around which is what i'm doing.

[No.3]

Originally Posted by StompinSteve

I've googled and googled but all I ever read is about converting European A3000's to North America spec. Have not found anything about the other way around which is what i'm doing.

Quite likely you will have to do it the other way round!?

Originally Posted by StompinSteve

Some say I need to swap an oscillator for a 50Hz one.

No, you'll have the replace the 28.6363 MHz NTSC oscillator with a 28.37516 MHz PAL one.

[Jope]

After you've swapped the jumper and replaced the oscillator, the PSU is very easy to modify to 240V. There is one jump wire's difference, and it's marked on the circuit board. It is added/removed depending on which input voltage you want the PSU to run at.

[StompinSteve]

Originally Posted by No.3

Quite likely you will have to do it the other way round!?

Isn't that what I wrote. I must convert from North American spec (NTSC) to Euro Spec (230V & PAL)

Originally Posted by No.3

No, you'll have the replace the 28.6363 MHz NTSC oscillator with a 28.37516 MHz PAL one.

Why is that, if I may ask? I mean, there is a jumper to swap modes.

On my European Amiga 500 rev5 (upgraded to ECS) i can simply select the mode I want in the early boot screen and it will happily switch between NTSC and PAL. And I isolated pin 41 on Agnus which makes it boot PAL by default instead of NTSC. And I can flip between 50 and 60Hz with AmigaTestKit on the fly.
Can the A3000 (also ECS) no do the same thing with the "Pin 41 trick" being replaced with a jumper?

[patrik]

If you want it to produce exact PAL timings, you need to change the oscillator.

J200 on the motherboard is the “Pin 41 trick”.

Some not that obvious things are affected from this oscillator btw, like serial port baud rate and the E-clock used for timing. I do not know if the code for that can correctly handle if you would only change the jumper, but not the oscillator. Not correct = you would get a small deviation in baud rate and timing. Anyone who knows?

[StompinSteve]

Originally Posted by patrik

If you want it to produce exact PAL timings, you need to change the oscillator.

I understand. Just ordered one of eBay. A German company sells new ones.

[Jope]

Originally Posted by patrik

Some not that obvious things are affected from this oscillator btw, like serial port baud rate and the E-clock used for timing. I do not know if the code for that can correctly handle if you would only change the jumper, but not the oscillator. Not correct = you would get a small deviation in baud rate and timing. Anyone who knows?

The difference is small enough to not matter in most cases, but at least I personally always swap the oscillator if I convert a machine's default boot frequency just to avoid problems.

[StompinSteve]

I agree. My personal Modus Operandi has always been "either do it right, or don't do it all". When I restore/convert a system, I go all the way. 100%
Same goes for my vintage motorcycles or cars: Do it right.

Originally Posted by Jope

The PSU is very easy to modify to 240V. There is one jump wire's difference, and it's marked on the circuit board. It is added/removed depending on which input voltage you want the PSU to run at.

Oh that would be great. Where can I read up on this? Can't find anything so far.

[Jope]

There used to be a website about it, but just crack the PSU open and look near the big filter caps. There's a spot in the silkscreen that says 110V on it. The wire between those 110V spots needs to be removed for 220V operation.

Here's a link to Amibay with pictures. https://www.amibay.com/threads/amiga...version.73029/

[No.3]

Originally Posted by patrik

Some not that obvious things are affected from this oscillator...

the most obvious thing is, that auto playback is done with a wrong replay rate i.e. audio is played "too fast".

[StompinSteve]

The A3000 is flying over the big pond as I write this. I'm a little apprehensive to modify the PSU's input voltage (i'm gonna open her up anyway to change the fan to a silent Noctua 80x80x25). At the start, I'll be using a 300W 230V -> 110V AC-AC converter to power the A3000 here. It's a common solution to run North American electrical stuff while in Europe so it will run fine.
At some point, when I feel brave enough, I might try the PSU modification.

Until then, does the PSU's input voltage has any relevance/relationship to modifying the Motherboard fully to PAL?
I ordered a 28.37516 MHz PAL oscillator. When I set Jumper J200 to PAL and install the PAL oscillator, will it work? Or will the PSU, still running at 110V, cause issues of any kind?

[StompinSteve]

Originally Posted by Jope

There used to be a website about it, but just crack the PSU open and look near the big filter caps. There's a spot in the silkscreen that says 110V on it. The wire between those 110V spots needs to be removed for 220V operation.
Here's a link to Amibay with pictures. https://www.amibay.com/threads/amiga...version.73029/

I found this "Amiga 3000 Technical Notes" website: http://amiga.serveftp.net/A3000_HardwareGuide/main.html

I has an article about the 110V -> 220V conversion (and the other way around). It speaks of that wire that needs to be desoldered BUT it also speaks about maybe needing to replacing a varistor:

"It is also advisable to replace varistor RV21 (located between AC input connector SW1 and inductor L3) with a 275V AC rated part as the original part may be a lower working voltage that is only suitable for 110V operation."

See this statement in context: http://amiga.serveftp.net/A3000_HardwareGuide/psu.html

If my PSU does not have such a varistor, I will buy one and solder it in during the conversion process.

So be careful. Just removing that wire might not be enough.
Maybe later PSU's all shipped with a 230V+ varistor, regardless of the Voltage version the PSU (standardised production).

That artice also answers my own question "does the PSU's input voltage has any relevance/relationship to modifying the Motherboard fully to PAL?" as it says:
"Set jumper J200 according to your AC mains frequency. The jumper is located on the A3000 main board beside Fat Agnus in approximately the centre of the expansion slot area. For a 50Hz supply the jumper should be set to PAL. For a 60Hz supply the jumper should be set to NTSC."

[StompinSteve]

Question: I'll be using a 300W 230V -> 110V AC-AC converter to power the A3000 here. It's a common solution to run North American electrical stuff while in Europe so it will run fine.
Now that I received the converter in the mail and read the booklet with the specs, it turns out that this converter output 110V at 50Hz.
North American PSU's work with 110V at 60Hz. Will this cause issues when I hook up my A3000 with it's North American PSU? Will some timings go bananas and cause wierd problems? Will it work at all as the PSU is designed to 60Hz. As you can tell, I have little knowledge about this specific topic...

As I wrote in my previous post: "Set jumper J200 according to your AC mains frequency. For a 50Hz supply, the jumper should be set to PAL. For a 60Hz supply the jumper should be set to NTSC.".

As this converter is effectively a 50Hz Power-supply, Am I done when I make the full PAL conversion (replace oscillator and J200) as everything runs at 50Hz. Is my thinking correct?

[Jope]

Yes. And you can just swap the jumper before you get around to swapping the oscillator.

[StompinSteve]

Edit: Moved to a new topic. This one became too tedious and confusion to read.
https://eab.abime.net/showthread.php...23#post1594323