Amiga 500+ Pal or NTSC?

[dJOS]

Fixed it, the previous owner of my mobo had joined jp4 together - I fixed it today and now my miggy defaults to PAL and the correct clock speed 7.09Mhz.

This proves to me that you dont need to change the crystal on a rev6a board at all as the 8372x Agnus can select the right frequency:

open JP4 = PAL & 7.09Mhz
closed JP4 = NTSC & 7.16Mhz

even with a 28.37516MHz clock crystal.

Im think I might add a switch for the rare occasions when I want NTSC.

[robinsonb5]

Originally Posted by dJOS

This proves to me that you dont need to change the crystal on a rev6a board at all as the 8372x Agnus can select the right frequency:

Couldn't swear to it, but I think it's more likely that SysInfo guesses the eclock based on whether Agnus reports NTSC or PAL (which is of course affected by the jumper), but the eclock itself won't actually change.

[dJOS]

Originally Posted by robinsonb5

Couldn't swear to it, but I think it's more likely that SysInfo guesses the eclock based on whether Agnus reports NTSC or PAL (which is of course affected by the jumper), but the eclock itself won't actually change.

After turning JP4 off, my eclock is now reported as 709379 same as an Aussie mates PAL a500.

[desiv]

Originally Posted by Schoenfeld

AmigaManiac's video converter may give you a colour picture on a video monitor even if you have the wrong crystal in the computer. However, his colour clock is NOT in sync with the rest of the chipset. This is bad design practise, as it'll produce constantly moving interference of the colour carrier on the picture. Both the NTSC and PAL video system were designed to get around such interference by syncing the colour carrier with the HSync signal, and the Amiga chipset is making good use of it. I'd suggest to look for an A520 of the right video system, and have the correct crystal frequency in your Amiga - this will give the best possible picture, one that's worthy of an Amiga.

I don't disagree with any of that technical information.
That being said, I own Amigamaniac's and an A520, and the actual results are stunningly in favor of Amigamaniac's "bad design." The picture looks great.
Cammy has some vids on youtube that people can check for themselves also..

For a "bad design," it outputs a great picture. ;-)

desiv

[kipper2k]

Originally Posted by desiv

I don't disagree with any of that technical information.
That being said, I own Amigamaniac's and an A520, and the actual results are stunningly in favor of Amigamaniac's "bad design." The picture looks great.
Cammy has some vids on youtube that people can check for themselves also..

For a "bad design," it outputs a great picture. ;-)

desiv

Amigamaniacs design is the same as the original Narmi design with a few more options and the same as the one i build. Quality is really good and rivals the Scart output, colours are not washed out and there is no tearing of the screen it also works well in either PAL/NTSC as proven on my Multi region TV and various PAL/NTSC boards. For $31 (which i charge) you can't beat the value

The only downfall is for the N. American user that cannot use scart is that the newer TV models are not including S-Video output so if you are thinking about using it, buy an S-Video capable TV before they all disappear.

[TjLaZer]

To keep it on topic: I finally got a Rev 8 A500+ motherboard from the UK (that did not have battery leak damage!!!) so I am in the process in building myself an A500+. I also got a A500+ top case.

I do not care that it is PAL. I can switch to NTSC and like others said, works fine if you have a RGB monitor (or a good LCD TV)

Cheaper way to do it than shipping a whole A500+ machine from Europe to Seattle!! I own several A500's so I got all the rest of the parts. :P

[TjLaZer]

Originally Posted by dJOS

Fixed it, the previous owner of my mobo had joined jp4 together - I fixed it today and now my miggy defaults to PAL and the correct clock speed 7.09Mhz.

This proves to me that you dont need to change the crystal on a rev6a board at all as the 8372x Agnus can select the right frequency:

open JP4 = PAL & 7.09Mhz
closed JP4 = NTSC & 7.16Mhz

even with a 28.37516MHz clock crystal.

Im think I might add a switch for the rare occasions when I want NTSC.

Is there a way to find out for SURE if this is indeed true? Would be ultra cool to just jumper JP4 to have NTSC.

Also is there a JP4 jumper on the Amiga 500 Plus? (I can't find one so far) I guess the only way to make it boot to NTSC on a PAL A500+ would be to put in a NTSC Agnus.

[dJOS]

You definitely can install a switch to change between pal/NTSC on rev6 boards - I can't see a way to do this as easily on the rev8 boards tho.

[TjLaZer]

Bump. That damn A500 plus I got back in 2012, that had no battery leakage, well it did a little, and it does not boot now. Looks like some traces got destroyed. I cleaned it real good when I removed the battery, which did not look like it leaked, but it did.

A few months later I got another A500 plus motherboard that had oddly had a NTSC 8375 318069-11 2MB Agnus on, but it still had the PAL oscillator on it. Seemed to boot in NTSC and work fine, so I decided to add a NTSC oscillator since I had one to finish it off and make it NTSC once and for all!