Very early Apple II bare logic board (green), 14.25″ x 8.5″, featuring the "Apple Computer, Inc." logo with a copyright date of 1978, hand-marked "ERIC" in the upper left corner. The part number, "820-0001-04," corresponds with the Apple II revision 4.
The early success of the Apple-1 in 1976 paved the way for the introduction of the Apple II in the spring of 1977. In Apple's 1980 IPO prospectus, the company described its progress: 'In April 1977 the Company introduced the Apple II computer mainframe which was similar to the Apple I but incorporated additional circuitry and a keyboard, and was packaged in a plastic housing.' In other words, the Apple II built upon the Apple-1 to become an even more capable, more consumer-ready machine. Between 1977 and 1980, on the sales of the Apple II and its peripherals, accessories, and software, Apple Computer's yearly revenue grew from $774,000 to $118 million, making it one of the great growth stories of Silicon Valley.
