Apple ii DOS

DOS and ProDOS were disk operating systems designed by Apple Computer, Inc. to run in the 8-bit Apple II line of computers. Apple also developed a 16-bit version of ProDOS to run in the Apple IIgs. DOS was released for the Apple II in the late 1970’s and was later replaced with ProDOS. ProDOS is much easier to use than DOS. Apple has always had an ease of use philosophy. You can tell by reading their older Apple II DOS or ProDOS manuals. They have always strived to make the computer experience as humanistic as possible. DOS and ProDOS are text-line OSs and as such are inherently harder to use than a GUI OS. Attempts to add a GUI to the older 8-bit Apple II’s (not withstanding the 16-bit IIgs) have all pretty much fallen flat. The Apple II simply does not have the graphical capabilities to support a convincing GUI. The Apple II, excluding the later IIgs, is a text-line machine, take it or leave it. You might expect that as a text-line machine, it would be hard to use and cryptic, especially if you are familiar with text-line operating systems like MSDOS. DOS and ProDOS were designed with as few keywords as possible. It was designed to make the levels of abstraction as few as possible. These operating systems are simple, elegant, and fun to use. They do not tax the user with multitudes of cryptic commands and hard to remember procedures. It is no wonder that the company that produced these powerfully simple text-line operating systems eventually changed the world with the Mac OS GUI.

History of DOS 3.3 and ProDOS

Apple’s DOS (Disk Operating System) was written to support their 5.25 inch floppy disk drive (Disk II) when it debuted in early 1978. Version numbers for software were not as strict as they are now. The code started at v0.1, and was incremented by 0.1 per revision. When delivered to Apple, it was at version 3.0. After modification, Apple released v3.1 as the first version shipped. Since Apple’s disk drive was single sided, all support for 5.25 inch DOS disks was single sided only.

With various bug fixes, DOS was at version 3.2.1 by 1979. These early releases supported only 13 sectors with 113.75K total space per disk side. With technological improvements to the disk interface card, 16 sectors could be fit in, for a total of 140K per side. DOS 3.3, released in 1980, was the first revision capable of handling 140K disks.

ProDOS was commissioned to be the “Professional Disk Operating System”, and was first part of the Apple III’s “Sophisticated Operating System”. Although the Apple III was a horrible marketing failure, ProDOS become the default standard for the Apple II. ProDOS was designed to be a replacement for DOS 3.3, and added many features not part of original DOS 3.3 such as support for disks other than the 5.25 inch drive, as well as directories and time stamping of files. A number of people have continued to use DOS 3.3 for various reasons, although ProDOS and various GS versions of it (ProDOS 16 and GS/OS) have become much more popular among Apple IIgs owners, as well as hard drive users.

Features of DOS 3.3

DOS 3.3 as released from Apple supports only the 113.75K and 140K 5.25 inch disk formats. It supports up to 105 files per side, no directory support, with very loose rules on filenames. It was initially bundled with Apple’s 5.25 inch drives (Drive II), so it won a lot of support for being free and usable. Since 1980, DOS 3.3’s 140K per 5.25 side has become the reigning standard for the DOS 3.x versions. DOS 3.x “System Master” disks could boot and run on any machine with at least 16K of memory (though 24-32K was recommended).

Due to some double buffering while reading and decoding files off disks, DOS 3.3 was not as fast as it could be. A few companies sold modified versions of DOS 3.3 to avoid the extra copy and thus dramatically speed up disk access; Beagle Bros’s ProntoDOS and many others were widespread. DOS 3.3 could also be modified to do other things, such as use a few more tracks on disk for extra space, relocate itself into the top 16K of memory on a 64K machine, but these were all third party patches, nothing official from Apple. Some of these patches and features came at the expense of the INIT command.

Apple ii Owners Manual

Apple introduced the Apple II in 1977. The Apple II line stayed in production until 1993. The Apple IIe variant, first released in 1983 and later upgraded in 1985 (Enhanced Apple IIe), can lay claim to one of the longest production runs of any computer in history. This feat is unheard of in today’s market place where top-of-the-line computers are generally considered out of date a few years after introduction. No company would think of trying to extend the life of the same basic computer with the same basic processor for well over ten years. But when Apple first began operations in the late 1970s, the home computer industry was young. Companies were not as hyper-competitive and there was no impetus for them to factor in “planned obsolescence” in their business strategies. Companies had to convince consumers that they actually needed a computer. You must keep in mind that the public had not grown up using computers and that few people knew what a computer was supposed to look like or act like. Apple had to in effect, create a new market. It did so by using a combination of clever marketing and by supporting the Apple II with easy to use manuals designed for a public that was skeptical, fearful, or indifferent about the prospect of home computing.

This article examines a portion of one of Apple’s Apple IIe owner’s manuals. Apple produced several different editions of the Apple IIe owner’s manual over the life of the computer. This one was not the first nor was it the last. This particular Apple IIe manual first shipped with the Apple IIe in 1984, the same year that Apple released the world-changing Macintosh. Reading through the manual is like taking a time machine back to 1984, when home computers where still relatively new and the Apple IIe drove the majority of Apple Computer’s sales revenue. Here are a few selected excerpts from the Apple IIe Owner’s Manual, copyright 1984, Apple Computer, Inc.

Apple encouraged users to upgrade the IIe. You practically had to upgrade it if you were going to get enough functionality out of the system for it to be truly powerful. The Apple IIe did not come with many standard ports, other than a joystick port, an audio jack, a composite monitor port, and a cassette tape player port. In order to add a disk drive, you needed to add a disk drive controller card. The same is true for other peripherals such as a printer, hard drive, or mouse.


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