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Macintosh Classic (I/II) analogboard recreation (820-0525-A)

daanvdl

Well-known member
I've been working on recreating the Macintosh Classic late revision analog board for quite a while.
This board can be reconfigured to both 110V as 240V, although i have not test 110V setup yet. This revision board should be able to replace any Classic I or II revision (early/late) analogboard.

The BOM, power- and monitorsection schematics are added to the GIT repository.
After deploying multiple boards, finetuning the recreation and continuing implementing improvements the day has come: I finished my work and published it to my github.

board.png

The files, schematic and BOM can be found overhere:

Have fun with it!

Cheers,
Daan
 

daanvdl

Well-known member
Ooh nice. Might have to do that with my Classic type B board if it comes to it.
Are there many differences between the Classic I and Classic II board types?
Apple did use mainly the early revision for the Classic I, and the late revision for Classic II, although i have seen the other way around.
I am not 100% sure if that is a later boardswap or a factory thing. Nevertheless; They are interchangeable.
 

68kPlus

Well-known member
Apple did use mainly the early revision for the Classic I, and the late revision for Classic II, although i have seen the other way around.
I am not 100% sure if that is a later boardswap or a factory thing. Nevertheless; They are interchangeable.
The Classic I type A board can't be used with a Type B yoke and vice versa though.
My Classic I is a Type B.
Anyway, do you have Type A and B PCBs?
 

daanvdl

Well-known member
The Classic I type A board can't be used with a Type B yoke and vice versa though.
My Classic I is a Type B.
Anyway, do you have Type A and B PCBs?
Regarding this threat the A/B yokes may be interchangeable pinwise, but i did not test that so i can not conform that. This board is a replica with the B-type yoke.
 
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68kPlus

Well-known member
Regarding this threat the A/B yokes are interchangeable, but i did not test that. This board is a replica of the B-type.

They're really not. I have a Type A CRT and a Type B, and the connectors are incompatible.
 

68kPlus

Well-known member
Regarding this threat the A/B yokes may be interchangeable pinwise, but i did not test that so i can not conform that. This board is a replica with the B-type yoke.
Yeah maybe pinwise, but I think the components on the board are also different, so I wouldn't want to try.
 

chiptripper

Well-known member
This is wonderful, thanks for doing this valuable work. I often run into Classic analog boards that are fouled by cap plague in the output circuit, I need some of these!
 

daanvdl

Well-known member
That's nice of you, thank you!
Many people don't understand how much work it is to get to an end result of a recreation. Many take these kind of boards for granted, while developing such boards takes months of work. In addition, the costs can never actually be recouped. I see it as a gift to society :)
 
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