Ultima I
Ultima II
Ultima III
Ultima IV
Ultima V
Ultima VI
Ultima VII
Ultima VII - Part 2
Ultima VIII
Ultima IX
Ultima Underworld I
Ultima Underworld II
Worlds of Ultima I
Worlds of Ultima II
Runes of Virtue I
Runes of Virtue II
Ultima Online
Ultima The Second Trilogy - IBM PC
Others: Special Edition

Other compilations

Ultima Collection Ultima IX + Ultima Online
Ultima Trilogy Underworld Series
Ultima I-VI Series Miscellaneous
The Complete Ultima VII  
Year of Release: 1991
Publisher: Origin Systems Inc.
Contents: Age of Virtue, Reference Guide, Install Guide, 1 cardboard map (16 x 16" / 40 x 40 cm), 13x 5.25" disk
The 'Second Trilogy' compilation consisting of Ultima IV - VI was released in 1991. The box had Ultima VI-like dimensions and came with all in all 13 disks (5.25") and a single book containing most (but not all) of the documentation from the original games. The included map is of the same type as the cardboard map from the Ultima VI Amiga version and later PC re-releases, it just reads 'The Second Trilogy - Ultima IV-VI' instead.