Congrats on finding your way back =)
Sounds like your in my shoes about the 4000 and all, im a step behind you there, the motherboard has issues, like a pregnant teenager with a drug habit sort of issues. i bought an a4000 and a1200 after about a year after i broke out the a600 and re-discovered the amiga.
Are you going for the indivision aga btw?
