Back to Table of Contents 4.10 2-PORT PRODUCTION MODIFICATIONS There are three production modifications to the logic board of 2-port 5200 systems. A number of people have seen these mods on their 5200s and the mods appear to have been factory installed. 1. Pin 11 of A5 (GTIA) is lifted out of the socket. This pin on the GTIA is the trigger 3 input which is unused on the 2-port model. When it is in the socket, it is connected to trigger 1. This mod probably had something to do with the change from 4-ports to 2. 2. Pins 8,9,10 and 11 of A7 (POKEY) are connected to pin 1 of A7 on the back of the board. This mod connects the paddle 4,5,6 and 7 inputs to ground. This mod also had something to do with the change from 4-ports to 2. 3. A wire is run from the feed thru below C94 to A27 pin 1, pin 1 and 2 of A27 are connected together on the back of the board, pin 10 of A15 is lifted, and connected to A27 pin 3. This modification alters the timing of CAS to the dynamic RAM. Back to Table of Contents