Apple II family

The Apple II family was the first series of computers made by Apple Computer in the late 1970s and early 1980s.

The progenitor was the Apple I, which was a hand-built machine sold to hobbyists. It was never produced in quantity.

The first large-scale production computer was the Apple II. It became popular with home users, as well as occasionally being sold to business users, particularly after the VisiCalc spreadsheet was released. See the Computing timeline for dates of machine releases, etc.

The first Apple II came with a MOS Technologies 6502 microprocessor running at 1 MHz, 4 KB of RAM, a tape cassette interface and the "Integer BASIC" programming language built into the ROMs. The video controller displayed 24 lines by 40 columns of upper-case-only text on the screen, with NTSC composite video output for display on a monitor or TV by way of an RF-modulator. Users could save and retrieve programs and data on audio cassettes; other languages, games, applications and other software were available on audio cassette too.

Later, an external 5.25" floppy disk drive and controller card that plugged into one of the computer's slots enabled much more convenient data storage and retrieval. The disk drive interface created by Steve Wozniak is still regarded as an engineering design marvel. The controller card had very little hardware support, relying on software timing loops instead to provide the necessary MFM encoding. That reduced the overall cost significantly, leaving the total system price low enough for home users. It also made it easy for proprietary software developers to make the media on which their applications shipped hard to copy by using tricks such as changing the low-level sector format or even stepping the drive's head between the tracks; however, other groups eventually sold software such as Copy II Plus[?] and Locksmith that could foil such restrictions.

Wozniak's open design and the Apple's multiple expansion slots permitted a wide variety of third-party devices to expand the capabilities of the machine. Serial controllers, improved display controllers, memory boards, hard disks, and networking components were available for this system in its day. There were also emulator cards, such as the Z80 card which permitted the Apple to switch to the Z80 processor and run a multitude of programs developed under the CP/M operating system such as the database dBase II[?] and the WordStar word processing program. There was also a third-party 6809 card with which one could run OS-9 Level One.

The Apple II was eventually superseded by a cost-reduced version, the Apple II Plus[?], which used newer chips that reduced the overall component count. It also included the Applesoft BASIC programming language (which added support for floating-point arithmetic but sacrificed integer performance in the process) in ROM (previously available as an upgrade) and had a total of 48 kilobytes of RAM, expandable to 64 KB through a "language card" that let users quickly switch between "INT" and "FP" (Applesoft) dialects of BASIC (but destroying any unsaved program in the process). Addition of the language card also enabled the use of UCSD Pascal, and a Fortran 77 compiler, which were released for the Apple at that time.

This was followed with the Apple IIe, which displayed both upper and lowercase letters and had 64 KB of RAM expandable to 128 KB. The IIe could also display high resolution text (80 columns) with an add-in 80 column card. The IIe was probably the most popular Apple II and was widely considered the "workhorse" of the line.

About the same time, a computer called the Apple III was produced. This was marketed to business users and was never especially successful.

Apple later produced their first portable Apple II called the Apple IIc. It featured onboard controllers for common devices such as disk drives, modems, etc., that previously required adapter cards. However, due to its compact design, the Apple IIc had limited expandability.

Along with the Apple IIc, Apple produced an Enhanced Apple IIe (identified by its numeric keypad) that used the new 65C02 processor[?]. Apple later licensed accelerator technology from Zip Technologies to produce the 4 MHz Apple IIc+, which also had a built-in 3.5" floppy drive in place of the older 5.25".

The final member of the line was the Apple IIGS computer, released in 1986 alongside the Macintosh SE[?] computer. The IIGS featured a 65C816 processor[?] with 16-bit registers, larger address space with more memory, better color, more peripherals (switchable between IIe-style card slots and IIc-style onboard controllers), and a user interface derived from Mac OS. Apple continued to sell and support the IIGS for a few years after the introduction of the Macintosh line, mainly due to its use in schools.

When Macintosh computers became powerful enough to emulate an Apple II computer, Apple began to phase out the II series in favor of Macintosh computers. This started with the Apple IIe Card that fit into one of the slots on the Macintosh LC[?] computer and connected to a 5-1/4 inch floppy drive.

Nowadays, even a PC running Microsoft Windows can emulate certain Apple II models with emulator software such as AppleWin[?] by copying the disk through a serial line. However emulators cannot run software on copy-restricted media unless somebody "cracks," or removes the copy restrictions from, the software. Numerous disk images for Apple II software are available free over the Internet.

External links

• Steven Weyrich's Apple II History (http://www.apple2history.org/)