Amiga Auckland Technical

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Amiga Technical References

For installation of 8372A or 8375 Agnus in an Amiga 2000:

For this you will need:

an 8372A Agnus or an 8375 Agnus
Phillips screw driver
small jewellers flathead screwdriver OR an exacto knife.
A PLCC chip extractor OR a small flathead screwdriver and a lot of patience
these instructions printed out since your machine will most likely be turned off

THE PROCEDURE:

Turn everything off.
Open the machine.
Remove the cover (5 screws, 2 on each side and one the back)
Remove the drive chassis (4 screws on the back and either 2 or 3 on the front)
Look on the motherboard, you will see a big square chip labelled something like 8370 and AGNUS written beside the socket. This is the chip you want to replace.
Remove the chip the easiest way you find possible. (small flathead screw driver and a lot of patience or just get a chip puller for a PLCC type chip)
Insert 8372A or 8375 Agnus. You MUST match up pin 1 on the chip with pin 1 on the socket/board. The chip has a dimple along one side that signifies pin 1 and the motherboard will have a 1 on it and in some cases the socket will have a dimple in it too. Match them! VERY IMPORTANT!
Make sure the chip is in solid.
Look for jumper J101 beside the power connector to the motherboard. Change it to the opposite position (pins 3 and 2 closest to the connection I believe)
Look for trace J500 at the back of the machine near the CIA's (8520's) It's a jumper trace that you will have to cut with a razor blade, small flat head screw driver or exacto knife.
Once all of this is done. Turn the machine on to see how it works.
Reassemble.
Enjoy!