This is an authentic 1981 spiral-bound technical reference manual for the Apple II and Apple II Plus. This foundational document was the "engineer's bible" for the early Apple ecosystem, featuring the complete theory of operation for the 6502 processor interface, memory maps, and I/O port assignments. It contains the high-detail logic schematics and timing diagrams that allowed hobbyists to build their own expansion cards and peripherals.

Manufacturer: Apple Computer Inc. (Cupertino, California)

Manufactured In: USA

Condition Description: This is an original vintage manual in Fair to Good condition. The plastic spiral binding is intact. The cover shows visible markings, shelf wear, and age-consistent tanning.

True Condition: There are some handwritten notes or markings on the interior pages, which add to the "provenance" of the item as a working technician's reference from the early 80s. See pictures for true condition.

Model Number: 1981 Revision (030-0004-03)

Extra Notes: This manual is famous for including the full firmware source code for the Apple II "Monitor" program and the Autostart ROM. It is the definitive resource for anyone performing a component-level restoration on an original Apple II Plus or early IIe motherboard.