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Atari Technical Bulletin TN001 - Mark - 07-24-2023
Technical Bulletin TN001
Date: 7 January 1986
Subject: 520ST RGB Output
Early models of the 520ST support seperate VSYNC (pin 12) and HSYNC (pin 9) for RGB.
The Thomson colour monitor CM36382 AR requires a combined SYNC input on (pin 20 of the SCART connector). 520ST's manufactured after Nov 85 have been modified to provide combined SYNC on pin 2 of the DIN connector.
These modified 520ST's can be identified by their serial number, as it should start with a 4.
The modification to the 520ST is as follows:
All components should be mounted on component side of PCB in area reserved for UHF modulator.
See PDF for schematic