Apple ProDOS

Apple ProDOS is a computer operating system of the Apple II series. It was released in version 1.0 in October 1983 as a replacement for Apple DOS 3.3 by Apple Computer, but based more on Apple SOS than on Apple DOS.

For BASIC programmers changed compared to Apple DOS relatively little ( a few new commands ), even if the internal structure of the system was quite different. The new operating system was but now assembly language programmers better development opportunities at hand, as there is a single entry point with all the necessary parameters offered - an art, as is common for all operating systems today. Programmers who used assembly language could thus be based on a standard, instead of the current DOS 3.3 to manipulate undocumented way and risking getting incompatibility with future versions. Furthermore, a better interrupt handling and a faster disk access were given. The only essential property of Apple DOS, which was not retained in ProDOS, was its support for the oldest Apple II model and for the obsolete Integer BASIC programming language of this model; so it was now at least an Apple II or Apple II plus € required, unless you wanted to use no BASIC programs. Also, the memory requirement of ProDOS was higher; ran DOS after only 20 KB of RAM, so needed ProDOS for machine language programs 48 KB, for use with BASIC 64 KB RAM. A memory of 64 KB was in 1983 but practically already given all still running Apple II computers through retrofitting.

Apart from Apple ProDOS had a relatively sophisticated hierarchical file system with features such as multiple logical drives on one physical drive, support for up to 20 different file types and 8 simultaneously open files. 140 KB 5 ¼ -inch floppy disks were still supported, the access to this was much faster than with Apple DOS. In addition, hard drives now supported with up to 32 MB per partition. All drives except the traditional 5 ¼ -inch floppy stations now each contained its own standardized driver in the firmware of their respective adapter cards, which also various 3 ½ -inch floppy drives and CD -ROM drives can be used later without further modification of the ProDOS - core under ProDOS were.

When the came out 16- bittige Apple IIgs, Apple ProDOS divided into the branches of Apple ProDOS 8 (for 8 -bit microprocessors ) and Apple ProDOS 16 (for 16 -bit microprocessors). The latter but was soon displaced by the graphical operating system GS / OS.

Versions

The latest version of Apple ProDOS 8 is released the 2.0.3 of 6 May 1993. It requires at least an Apple IIc or an "enhanced" Apple IIe, the supplied utility programs also require at least 128 KB of memory. On the Apple II and the non - "enhanced" IIe version runs for a maximum of 1.9.