Here is steps to convert a PAL 1200 to a native NTSC A1200

[kipper2k]

Thought i'd share this, its tried and tested to work good...

A1200 PAL to NTSC Conversion (this is on a Rev 2B PAL board). A NTSC board can also be swapped over to PAL bt you will obviously have to find a few more components.

The following tutorial will explain how to convert a PAL A1200 to a NTSC native A1200

Items that must be altered

(T) = top
(B) = bottom

- Remove R245 (B)
- Add R246 (T) 2.7K
- Change X1 (T) to a 28.6363MHz oscillator
- Remove Y451 (T)
- Remove C244 (B)
- Add R203 (B) 0 ohm resistor
- Add R225 (B) 0 ohm resistor
- Change R221 (B) to 1.2k
- Change R223 (B) to 1.2k

Items that may be required to alter
C243 removed (T)
L241 removed (T)
Q461 removed (T)
Z221 removed (T)
R243 removed (B)
R244 removed (B)
C244 removed (B)

Just altering the upper list of components was enough to convert to NTSC. the lower list will remove extra components from the Pal goodies section of the motherboard that don't appear to be necessary.


enjoy

[papa_november]

So this gives you a machine that A. boots in 50 hz and B. outputs NTSC composite from the composite jack?

[kipper2k]

Originally Posted by papa_november

So this gives you a machine that A. boots in 50 hz and B. outputs NTSC composite from the composite jack?

Yup, this will make it a REAL NTSC computer

[Khyron]

Originally Posted by papa_november

So this gives you a machine that A. boots in 50 hz and B. outputs NTSC composite from the composite jack?

It'll start in 60Hz with an NTSC composite. If you do plan to use the composite..
Don't remove Z221
Don't Add R225
Leave R221 and R223 at the same value and if the composite image is too bright then change R221 to 1.2K
You can also remove R202 as well