stevep
Well-known member
After looking through all the topics in this forum, I don't see that this has come up before; my apologies if it has.
I have two logic boards, both marked as Classic II and dated 1991 - one numbered 820-0401-A with 4 ROM chips, the other numbered 820-0626-B with 2 ROM chips. The first one (4 chips) has the blue wire stuck on it as mentioned in some posts.
Does anyone know what the difference(s) are and when the change happened? One of the machines these came from was made October 1991 (4 chip) and the other October 1992 (2 chip).
Even Larry Pina's "Mac Classic & SE Repair and Upgrade Secrets" does not acknowledge the 2 chip board. It shows board 820-0401-A having 4 ROM chips.
I have two logic boards, both marked as Classic II and dated 1991 - one numbered 820-0401-A with 4 ROM chips, the other numbered 820-0626-B with 2 ROM chips. The first one (4 chips) has the blue wire stuck on it as mentioned in some posts.
Does anyone know what the difference(s) are and when the change happened? One of the machines these came from was made October 1991 (4 chip) and the other October 1992 (2 chip).
Even Larry Pina's "Mac Classic & SE Repair and Upgrade Secrets" does not acknowledge the 2 chip board. It shows board 820-0401-A having 4 ROM chips.