Apple ProDOS

Apple ProDOS

Apple ProDOS (Professional Disk Operating System) is an operating system developed by Apple Inc. for the Apple II series of personal computers. Released in 1983, ProDOS was designed to replace the earlier Apple DOS 3.3, offering improved features and capabilities.

History

ProDOS was introduced as a successor to Apple DOS 3.3, which had been the standard operating system for the Apple II since 1980. The development of ProDOS was driven by the need for a more robust and flexible operating system that could support larger storage devices and more complex applications.

Features

ProDOS introduced several key features that distinguished it from its predecessor:

• Hierarchical File System: Unlike Apple DOS 3.3, which used a flat file system, ProDOS supported a hierarchical file system, allowing for directories and subdirectories. This made file organization more efficient and intuitive.

• Support for Hard Drives: ProDOS was designed to support larger storage devices, including hard drives, which were becoming more common in the early 1980s.

• Improved Memory Management: ProDOS could manage memory more effectively, allowing for larger and more complex programs to run on the Apple II.

• Time and Date Stamping: Files in ProDOS could have time and date stamps, which was a significant improvement for file management and organization.

Technical Specifications

ProDOS was written in 6502 assembly language and was designed to run on any Apple II computer with at least 64KB of RAM. It was compatible with a wide range of Apple II models, including the Apple IIe, Apple IIc, and Apple IIgs.

System Requirements

• Processor: MOS Technology 6502 or compatible
• Memory: Minimum 64KB RAM
• Storage: Compatible with 5.25-inch floppy disks, 3.5-inch floppy disks, and hard drives

Versions

ProDOS went through several versions during its lifetime, each adding new features and improvements:

• ProDOS 1.0: The initial release in 1983, which introduced the basic features of the operating system.
• ProDOS 1.1: Released in 1984, this version included bug fixes and minor enhancements.
• ProDOS 1.2: Introduced support for the Apple IIc and additional hardware.
• ProDOS 2.0: Released in 1988, this version included significant improvements and was the last major update.

Legacy

ProDOS was a significant step forward for the Apple II series, providing a more modern and capable operating system. It remained in use throughout the 1980s and into the early 1990s, even as newer systems like the Apple Macintosh began to dominate the market.

See Also

• Apple DOS
• Apple II
• Apple Inc.

References

• "ProDOS Technical Reference Manual," Apple Inc.
• "The Apple IIc Technical Reference Manual," Apple Inc.