Last weekend I got (myself) an Amiga 600 Rev. 2,only problem.. it was a NTSC version.. not PAL.. Board is MINT..
So I decided to convert the hardware from NTSC to PAL.
Discussed a bit about it with Peter Mulholland & Tristan Zondag about (maybe) just cut pin 41 of the Agnus chip.. Tristan stated that won’t work.. Commodore made an Agnus for PAL and NTSC.. only difference.. pin 41 attached to internal ground or to (internal) pullup resistor.. THAT IS THE ONLY DIFFERENCE.. HUH..?!
So Let’s start.. i replaced the X1 28.6363 Mhz Oscillator and the NTSC Agnus ( 318069-11 ( NTSC VERSION) ) (U2).
Now i have a sort of black & white picture with lines from the composite output..
Before the replacement I had color, but my display, showed me it was NTSC signal..
So now it’s time to add all PAL components to the board, they are not on a NTSC board by default.
Everthing on it’s place.. YEAH we got PAL.. 🙂
Looks pretty good..
Part list to add / replace to the board..
X1: 28.37516 MHz Oscillator ( replace )
U2: Agnus 318069-10 ( replace )
U33: 74LS74A
Y451: 4.433619Mhz Oscillator
L241: 1.2uH
R241: 4.7K
R242: 6.8K
R243: 10K
R244: 1K
R245: 2.7K
C241: 56pF
C242: 15pF
C243: 1nF ( 1000pF )
C244: 10nF ( 0,01uF )
Pictures
This is what must be done to get composite working again..
Old NTSC components: 28.6363 Osc and Agnus ( 318069-11 )
Removed Agnus..
We got PAL composite, but b/w, because the PAL circuit is not present..
New PAL osc 28.37516 MHz and Agnus ( 318069-10 )
Solder result
Missing components of the NTSC board
Osc and other components on the right place
we got color on composite
we got color on composite, looks good.. and PAL
Giana sisters.. on PAL