Apple II Plus
The Apple II Plus (1979) refined Apple’s early mass-market computer with a 1 MHz MOS 6502 processor, built-in Applesoft BASIC, up to 48 KB RAM as sold, floppy-disk autostart, color graphics, and eight expansion slots, making it both approachable for programming and unusually adaptable for home, school, and small-business use.

[Vin 210]
- Manufacturer: Apple Computer Inc.
- Released: June 1979
- Type: Personal Computer
- Cost at release starter system: 16 KB machine + cassette recorder: ~$6,000 (adjusted for inflation)
- Cost with peripherals (Business Manager’s system: 48 KB machine, two Disk II drives, 9-inch monochrome monitor, printer/controller, and business software): ~$23,500 (adjusted for inflation)
- MIPS: 0.5 (500 KIPS)
Hardware Specifications
- CPU: MOS Technology 6502, approximately 1.02 MHz
- Memory: 16 KB, 32 KB, or 48 KB installed; expandable to 64 KB with the optional 16 KB Language Card, 12 KB ROM.
- Audio: Built-in 1-bit speaker, suitable for clicks, beeps, tones, and simple game sound
- Storage: Built-in cassette-tape interface; optional external 5.25-inch Disk II floppy drive via an expansion-card controller
- Disk II capacity: Ӱԭ 140 KB per 5.25-inch floppy disk
- Expansion: Eight internal 50-pin expansion slots, numbered 0–7, for disk controllers, serial/parallel interfaces, printer cards, memory cards, CP/M Z80 cards, and other
- Graphics: Low-resolution graphics: 40 × 48 pixels, 16 colours. High-resolution graphics: 280 × 192 pixels, six displayable colours in standard NTSC modes
- Video output: Composite NTSC video for a monitor or television; RF output available through an optional modulator
- Audio: Built-in 1-bit speaker, suitable for clicks, beeps, tones, and simple game sound
- Storage: Built-in cassette-tape interface; optional external 5.25-inch Disk II floppy drive via an expansion-card controller
- Disk II capacity: Ӱԭ 140 KB per 5.25-inch floppy disk
Operating System & Programming Languages
- Operating Systems
- Applesoft BASIC: Built into the II Plus ROM. It provided the immediate command-line environment on a machine without a bootable disk.
- Apple DOS 3.2 / DOS 3.3: The principal Disk II floppy-disk operating systems of the II Plus era. DOS 3.3 was normally supplied with Disk II hardware and handled booting, files, and disk access.
- Apple Pascal / UCSD Pascal system: A disk-based Pascal environment and operating system, typically requiring the 16 KB Language Card.
- ProDOS: Introduced later, in 1983. An Apple II Plus could use it if fitted with a Language Card / appropriate extra memory.
- CP/M: Available through a Z80 expansion card—most famously Microsoft’s Z-80 SoftCard—allowing access to the extensive CP/M software world.
- Programming Languages
- Applesoft BASIC: The built-in floating-point Microsoft BASIC dialect; it was the II Plus’s defining programming language.
- Integer BASIC: Not built into the II Plus, unlike the original Apple II, but it could be loaded from disk or provided through firmware.
- 6502 assembly language: Direct low-level programming through the built-in machine-code monitor, commonly entered with
CALL-151. - UCSD Pascal / Apple Pascal: A significant structured-programming option, released for the Apple II in 1979.
- Apple FORTRAN: An ANSI X3.9-1978 FORTRAN implementation, run under the Pascal environment and requiring a 48 KB configuration.
- Logo: Available for education and turtle-graphics programming.
- Forth: Available in multiple commercial and hobbyist implementations.
- C and Modula-2: Available later through third-party systems, generally requiring substantial disk and memory resources.
- COBOL: Available in limited form under CP/M via the Z80 SoftCard, rather than as a native 6502 Apple II environment.bitsavers.informatik.uni-stuttgart+2
Notables
- **Apple ][+ / Apple II Plus:** Commonly styled with square brackets, “Apple][+,” echoing the machine’s distinctive logo.
- Released in 1979, its most consequential changes were Applesoft BASIC in ROM and the Autostart ROM, which could automatically boot a Disk II floppy instead of dropping every user into a low-level monitor.
- The first major personal-computer spreadsheet, VisiCalc (“visible calculator”), appeared first on the Apple II in 1979 and became the platform’s classic killer app: a program useful enough to justify buying the computer.
- Unlike the kit-like Apple I, the Apple II family arrived as a finished product with enclosure, keyboard, power supply, colour graphics, and expansion slots marketed for ordinary homes, schools, and workplaces.
- Its eight internal expansion slots enabled owners to add Disk II controllers, printers, serial ports, extra RAM, graphics hardware, and even a Z80 card for CP/M compatibility.
- Apple II systems became fixtures in North American classrooms; for many students of the 1980s, an Apple II was their first hands-on computer experience.
- The long-lived Apple II line became Apple’s first major commercial success and provided the financial and organizational base from which the company later developed the Macintosh
Donated By: Ӱԭ University Library / Prof. Thomas Kunz