Twentieth Anniversary Macintosh - "Umbilical Cord" Documentation

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Stephen

BetterBit
Staff member
Founder
Sep 5, 2021
208
258
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San Francisco
cable.png


TAM Umbilical Cord
I've documented the TAM "Umbilical Cord" for anyone who does not have a base unit or would like more information while debugging / repairing their base unit. All of the information is available in my GitHub repo.




connector_screenres.png

Connector
Pin​
ConnectorLabel
1​
J2 Pin 7AMP OE
2​
3​
J2 Pin 14AMP RHS
4​
5​
J2 Pin 10SPKR RHS
6​
J2 Pin 9SPKR RTRN
7​
J2 Pin 8SPKR LHS
8​
J2 Pin 12AMP RTRN
9​
J2 Pin 13AMP LHS
10​
J2 Pin 4PFW
11​
J2 Pin 6-12V
12​
J2 Pin 25V
13​
J16 Pin 25V
14​
J16 Pin 6GND
15​
J2 Pin 3GND
16​
17​
J2 Pin 15V
18​
J16 Pin 35V
19​
J16 Pin 7GND
20​
GNDGND
21​
J16 Pin 8GND
22​
J16 Pin 112V
23​
J2 Pin 512V



TAM_UMBILICAL_J2_AUDIO.png

J2 - Audio Connector
Pin​
SourceConnections
1​
5VJ3 Pin 7 (Sense)
2​
5VTrickle to J3 Pin 3, C3(+)
3​
GNDJ3 Pin 4 (Sense)
4​
PFWJ3 Pin 5
5​
12VJ16 Pin 1,5 (Sense), C1(+), C19(+), C20(+)
6​
-12VC4, J3 Pin 1
7​
AMP OEU1
8​
SPKR LHSJ15 Pin 3
9​
SPKR LHS RTRNR31, J15 Pin 2
10​
SPKR RHSJ1 Pin 2
11​
SPKR RHS RTRNR31, J31 Pin 2
12​
AMP RTRNJ3 Pin 13, R25
13​
AMP LHSJ3 Pin 14
14​
AMP RHSJ3 Pin 12
15​
NA
16​
NA



TAM_UMBILICAL_J16_POWER.png
J16 - Power Connector
Pin​
SourceConnections
1​
12VC1(+), C19(+), C20(+), J2 (Sense)
2​
5VC2
3​
5VC2
4​
5VC2
5​
12VC1(+), C19(+), C20(+), J2 (Sense)
6​
GNDC1, C19, C20, C2, C3, C4(+)*
7​
GNDC1, C19, C20, C2, C3, C4(+)*
8​
GNDC1, C19, C20, C2, C3, C4(+)*
* The negative connector of C4 is -12V


Orientation & Overview
diagram_screenres.jpg