Community hub
Recent from talks
Knowledge base stats:
Talk channels stats:
Members stats:
Apple ProDOS
ProDOS is the name of two similar operating systems for the Apple II line of personal computer. The original ProDOS, renamed ProDOS 8 in version 1.2, is the last official operating system usable by all 8-bit Apple II computers, and was distributed from 1983 to 1993.[citation needed] The other, ProDOS 16, was a stop-gap solution for the 16-bit Apple IIgs that was replaced by GS/OS within two years.
ProDOS was marketed by Apple as meaning Professional Disk Operating System, and became the most popular operating system for the Apple II 10 months after its release in January 1983.
ProDOS was released to address shortcomings in the earlier Apple operating system (called simply DOS), which was beginning to show its age.
Apple DOS only has built-in support for 5.25" floppy disks and requires patches to use peripheral devices such as hard disk drives and non-Disk-II floppy disk drives, including 3.5" floppy drives. ProDOS adds a standard method of accessing ROM-based drivers on expansion cards for disk devices, expands the maximum volume size from about 400 kilobytes to 32 megabytes, introduces support for hierarchical subdirectories (a vital feature for organizing a hard disk's storage space), and supports RAM disks on machines with 128 KB or more of memory. ProDOS addresses problems with handling hardware interrupts, and includes a well-defined and documented programming and expansion interface, which Apple DOS had always lacked. Although ProDOS also includes support for a real-time clock (RTC), this support went largely unused until the release of the Apple IIgs, the first in the Apple II series to include an RTC on board. Third-party clocks were available for the II Plus, IIe, and IIc, however. ProDOS shipped with a built-in clock driver for the Thunderware Thunderclock, which was a common real-time clock card in Apple II+ and IIe systems; other clock hardware required replacing the Thunderclock driver with a driver for the other clock.
ProDOS, unlike earlier Apple DOS versions, has its developmental roots in SOS, the operating system for the ill-fated Apple III computer released in 1980. Pre-release documentation for ProDOS (including early editions of Beneath Apple ProDOS) documented SOS error codes, notably one for switched disks, that ProDOS itself could never generate. Its disk format and programming interface are completely different from those of Apple DOS, and ProDOS cannot read or write DOS 3.3 disks except by means of a conversion utility; while the low-level track-and-sector format of DOS 3.3 disks was retained for 5.25-inch disks, the high-level arrangement of files and directories is completely different. For this reason, most machine-language programs that run under Apple DOS will not work under ProDOS. However, most BASIC programs work, though they sometimes require minor changes. A third-party program called DOS.MASTER enables users to have multiple virtual DOS 3.3 partitions on a larger ProDOS volume.
With the release of ProDOS came the end of support for Integer BASIC, on the original Apple II model, which had long since been effectively supplanted by Applesoft BASIC on the Apple II Plus, and later models. (Though ProDOS, itself, and many programs, still run on an original Apple II.) Whereas DOS 3.3 always loads built-in support for BASIC programming, under ProDOS this job is given to a separate system program called BASIC.SYSTEM, which one launches to run and write Applesoft BASIC programs. BASIC itself continued to be built into the Apple ROMs; BASIC.SYSTEM is merely a command interpreter enhancement that allows BASIC programs to access ProDOS by means of the same "Control-D" text output they had used under DOS 3.3. BASIC.SYSTEM alone requires about as much memory as the whole of DOS 3.3. Since the ProDOS kernel itself is stowed away in the "Language Card" RAM, the usable amount of RAM for BASIC programmers remains the same under ProDOS as it had been under DOS 3.3.
Despite ProDOS's many advantages, many users and programmers resisted it for a time because of their investment in learning the ins and outs of Apple DOS and in Apple-DOS-based software and data formats. A contributing reason was that ProDOS allows only 15 characters in a filename compared to Apple DOS's 30. But Apple's integrated software package AppleWorks, released in 1984, proved a compelling reason to switch, and by the end of 1985 few new software products were being released for the older operating system. Apple IIs continued to be able to boot the older DOS (even the Apple IIGS can boot the older DOS floppies) but as 3.5" floppies and hard disks became more prevalent, most users spent the bulk of their time in ProDOS.
The Apple IIe, also released in 1983, was the first Apple II computer to have 64 KB of memory built in. For a while, Apple shipped both DOS 3.3 and ProDOS with new computers.
Hub AI
Apple ProDOS AI simulator
(@Apple ProDOS_simulator)
Apple ProDOS
ProDOS is the name of two similar operating systems for the Apple II line of personal computer. The original ProDOS, renamed ProDOS 8 in version 1.2, is the last official operating system usable by all 8-bit Apple II computers, and was distributed from 1983 to 1993.[citation needed] The other, ProDOS 16, was a stop-gap solution for the 16-bit Apple IIgs that was replaced by GS/OS within two years.
ProDOS was marketed by Apple as meaning Professional Disk Operating System, and became the most popular operating system for the Apple II 10 months after its release in January 1983.
ProDOS was released to address shortcomings in the earlier Apple operating system (called simply DOS), which was beginning to show its age.
Apple DOS only has built-in support for 5.25" floppy disks and requires patches to use peripheral devices such as hard disk drives and non-Disk-II floppy disk drives, including 3.5" floppy drives. ProDOS adds a standard method of accessing ROM-based drivers on expansion cards for disk devices, expands the maximum volume size from about 400 kilobytes to 32 megabytes, introduces support for hierarchical subdirectories (a vital feature for organizing a hard disk's storage space), and supports RAM disks on machines with 128 KB or more of memory. ProDOS addresses problems with handling hardware interrupts, and includes a well-defined and documented programming and expansion interface, which Apple DOS had always lacked. Although ProDOS also includes support for a real-time clock (RTC), this support went largely unused until the release of the Apple IIgs, the first in the Apple II series to include an RTC on board. Third-party clocks were available for the II Plus, IIe, and IIc, however. ProDOS shipped with a built-in clock driver for the Thunderware Thunderclock, which was a common real-time clock card in Apple II+ and IIe systems; other clock hardware required replacing the Thunderclock driver with a driver for the other clock.
ProDOS, unlike earlier Apple DOS versions, has its developmental roots in SOS, the operating system for the ill-fated Apple III computer released in 1980. Pre-release documentation for ProDOS (including early editions of Beneath Apple ProDOS) documented SOS error codes, notably one for switched disks, that ProDOS itself could never generate. Its disk format and programming interface are completely different from those of Apple DOS, and ProDOS cannot read or write DOS 3.3 disks except by means of a conversion utility; while the low-level track-and-sector format of DOS 3.3 disks was retained for 5.25-inch disks, the high-level arrangement of files and directories is completely different. For this reason, most machine-language programs that run under Apple DOS will not work under ProDOS. However, most BASIC programs work, though they sometimes require minor changes. A third-party program called DOS.MASTER enables users to have multiple virtual DOS 3.3 partitions on a larger ProDOS volume.
With the release of ProDOS came the end of support for Integer BASIC, on the original Apple II model, which had long since been effectively supplanted by Applesoft BASIC on the Apple II Plus, and later models. (Though ProDOS, itself, and many programs, still run on an original Apple II.) Whereas DOS 3.3 always loads built-in support for BASIC programming, under ProDOS this job is given to a separate system program called BASIC.SYSTEM, which one launches to run and write Applesoft BASIC programs. BASIC itself continued to be built into the Apple ROMs; BASIC.SYSTEM is merely a command interpreter enhancement that allows BASIC programs to access ProDOS by means of the same "Control-D" text output they had used under DOS 3.3. BASIC.SYSTEM alone requires about as much memory as the whole of DOS 3.3. Since the ProDOS kernel itself is stowed away in the "Language Card" RAM, the usable amount of RAM for BASIC programmers remains the same under ProDOS as it had been under DOS 3.3.
Despite ProDOS's many advantages, many users and programmers resisted it for a time because of their investment in learning the ins and outs of Apple DOS and in Apple-DOS-based software and data formats. A contributing reason was that ProDOS allows only 15 characters in a filename compared to Apple DOS's 30. But Apple's integrated software package AppleWorks, released in 1984, proved a compelling reason to switch, and by the end of 1985 few new software products were being released for the older operating system. Apple IIs continued to be able to boot the older DOS (even the Apple IIGS can boot the older DOS floppies) but as 3.5" floppies and hard disks became more prevalent, most users spent the bulk of their time in ProDOS.
The Apple IIe, also released in 1983, was the first Apple II computer to have 64 KB of memory built in. For a while, Apple shipped both DOS 3.3 and ProDOS with new computers.