|Full Name||Saburo McIntosh|
|Personifies||Macintosh System 3.0|
|Height||130 cm (4 feet 3 inches)|
|Affiliation||Retrograde Conglomerate (Member), The Infinite Loop (Past Member)|
Macintosh System 1 & 2
Out of the triplets, he tries to stay out of trouble but seem to fail most of the time.
His formal and intellectual personality is a trait he inherited from her, as she herself possesses a formal and scholarly demeanour.
The son of XEROX Alto-kun, Macintosh System 3-kun and Xerox Alto-kun have a complicated relationship. Alto is the father of System 3, but he left Lisa when the triplets were young. As a result, System 3 doesn't know much about him and hardly ever sees him.
The only time System 3 really got to know his father was when Alto tried to sue Lisa for custody of the triplets In the end, Lisa won custody, and Alto was ordered to pay child support.
Macintosh System 3-kun is aware of XENIX-tan because of Lisa-tan.