Original late-1970s IBM field service engineer documentation binder covering IBM 5110 and 5120 systems.

Includes:

• IBM 5120 Computing System Logic Manual – First Edition (December 1979)

• IBM 5110 Model 3 Maintenance Information Manual

• 5110 Model 3 Parts Catalog

• IPAR Functional Unit & Cause Code Guide

• Technical Newsletter inserts

• Power Distribution and logic sections

• Fold-out engineering diagrams

• Original IBM Customer Engineer (CE) Log sheets

Also included is an original sealed IBM packet labeled:

“PACKET CONTENTS FOR I.B.M. CUSTOMER ENGINEER USAGE ONLY”

Sealed hardware components remain in original IBM plastic packaging.

These materials were issued to IBM field service personnel and were not general consumer publications. Surviving examples with sealed service packet components are uncommon.

Pages show normal age-related wear consistent with late 1970s documentation. Manuals appear complete. Binder intact.

An excellent archival piece for collectors, restorers, museums, or vintage computing enthusiasts.

Please review all photos carefully for condition details.