# A2osX and ProDOS
### Updated January 27, 2020
As discussed in the **[Users Guide](.Docs/User%20Guide.md)**, A2osX runs on top of ProDOS, leveraging its support for block devices such as floppy drives, hard drives, SmartPort drives, etc.; it is limited in its ability to implement certain features based on the capabilities of the underlying operating system, in this case ProDOS. This document will provide an overview of those features and their availability or absence from several versions of ProDOS including two new versions of ProDOS created by the makers of A2osX.
## History
ProDOS is the name of two similar operating systems for the Apple II series of personal computers. The original ProDOS, renamed ProDOS 8 in version 1.2, is the last official operating system usable by all 8-bit Apple II series computers, and was distributed from 1983 to 1993. The other, ProDOS 16, was a stop-gap solution for the 16-bit Apple IIgs that was replaced by GS/OS within two years. As A2osX only runs under ProDOS 8, this document will largely concentrate on the various versions of that operating system.
ProDOS was marketed by Apple as meaning Professional Disk Operating System, and became the most popular operating system for the Apple II series of computers 10 months after its release in January 1983. The original Apple II operating system, DOS only had built-in support for 5.25" floppy disks and required patches to use peripheral devices such as hard disk drives and non-Disk-II floppy disk drives, including 3.5" floppy drives. ProDOS added 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, introduced support for hierarchical sub directories (a vital feature for organizing a hard disk's storage space), and supports RAM disks on machines with 128kB or more of memory (or with special RAM based interface cards). 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 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.
## New A2osX ProDOS Versions
The A2osX team is proud to announce the availability of two new versions of ProDOS, one with a very minor tweak and the other a major update/overhaul. These are discussed in detail below, but briefly there is ProDOS 2.03tc which is an 8 byte patch to ProDOS 2.03 to update the year table to support years through 2023 and ProDOS FX a **F**aster and e**X**tended version that adds many new features including lower case file, directory and volume name support. These new versions are already being included in the latest **Stable** media and will become the versions of ProDOS supplied on all future media. Please consult our **[Media Guide](.Docs/Media%20Guide.md)** for more information about which version is included on each media image.
## Tested Versions
ok, back on Prodos…. I am going to close saying, we test both 2.03 and 2.42. people can use what they like (look at User Guide on installing a2osx on your own HD/booting your own prodos). Have nice day. Nothing to be said of FX. I think one question to answer in future is when you do ProDos FX, will a2osx stop working on standard prodos?
For 0.93, the current project milestone, we have decided to include on the A2osX media a very slightly modified version of 2.0.3 which you will notice during boot of ProDOS is labeled as 2.0.3tc. This stands for ThunderClock and basically this version is an exact copy of 2.0.3 with 7 bytes changed to update the ProDOS year table to be current (it is the same work to correct the year that is done in 2.4.2/2.5 by John Brooks). Note, we do test A2osX regularly with other versions of ProDOS (the author of this note regularly runs 2.4.2). For consistency and support we will standardize on 2.03tc for this release and readdress which version of ProDOS should be included when we start creating 0.94 builds.
Also note, users can replace ProDOS with another version, or as is expected for many with hard drives/emulators, they can install A2osX onto a subdirectory of their HD/Drive which boots their preferred version of ProDOS. In fact, we are planning for an upcoming release an “INSTALL” method that will create this subdirectory, copy the necessary files and make any changes to A2osX config files needed so people can run A2osX in this manner.
## Version Overview Chart
The following chart lists all the known (to the author) versions of ProDOS and
| Version | Status | Lower
Case | Clock | Remapping | File
Size |Notes |
| --- | --- | --- | --- | --- | --- | --- |
| 1.0 | | No | TC | No| 15360| |
| 1.0.SEP | Not Tested | No | TC |No | 14336| |
| 1.0.NOV | Not Tested | No | TC | No|15360 | |
| 1.0.1 | Not Tested | No | TC |No |15360 | |
| 1.0.2 | Not Tested | No | TC |No | 15360| |
| 1.1.1 | Not Tested | No | TC |No |14848 | |
|ProDOS 8 /
1.2 | | No | TC 1991|Simple |15485 | |
| 1.3 | Not Tested | No | TC 1991|Simple |15485 | |
| 1.4 | Not Tested | No | TC 1991|Simple |15485 | |
| 1.5 | Not Tested | No | TC 1991|Simple |15485 | |
| 1.6 | Not Tested | No | TC 1991|Simple |15485 | |
| 1.7 | Not Tested | No | TC 1991|Simple |15485 | |
| 1.8 | Not Tested | No | TC 1991|Simple |15741 | |
| 1.9 | Not Tested | No | TC 1991|Simple |16509 | |
|2.0.1 | Not Tested | No | TC 1999|Enhanced|17128 | |
| 2.0.2 | Not Tested | No | TC 1999 |Enhanced| 17128| |
| 2.0.3 |Working w/ Issues | No | TC 1999 |Enhanced |17128 | Date/Years not current |
| 2.0.3tc |Working | No | TC 2023|Enhanced |17128 | |
| 2.4 | Not Tested | No | TC 1999|Enhanced |17128 | |
| 2.4.1 | Not Tested | No | TC 1999| Enhanced| 17128| |
| 2.4.2 |Working | No | TC 2023| Enhanced|17128 | |
| 2.5.0a8 |Working w/ Issues | No | TC 2924|Advanced | 16616| |
| FX || Yes | TC 2023
NSC
GS/Cortland | Advanced| 15244| |
| FX Paked || Yes | TC 2023
NSC
GS/Cortland | Advanced|13295 | |
### Drive Remapping
With the release of ProDOS 8 (Version 1.2) Apple Modified the ProDOS 8 loader code to automatically install up to four drives in slot 5 if a SmartPort device is found using slot 2 for the extra 2 drives. With ProDOS 8 Version 2.0.1, ProDOS supports more than two SmartPort devices per slot by remapping the third device and beyond to different slots. There's still a limit of 14 devices altogether, though.
### Clock Support
WHile you are on that.... I am working on an updated readme to go with next RC.... I am going to talk about new FX and how it supports LC (I think we need to talk more about FILE file File fILe...) and more info about FX.PAK on 140K media. Is there anything else in FX to note [oh SP drive mapping stuff from produs enhancement channel). Also in readme new PAK/UNPAK, TERM, ask for more devs, testers, especially with HW, and some doc readers would be nice. Further on Pdos, say we have tested on 2.5a8 and works, unsupported at this time (you can file issue but may not be addresses). known that date display in LS no work becasue 2.5 breaks standard and we may not adapt. 8 drive per slot "?works" but a2 reports multiple drives as D1/2 and again non-standard we may not change/adapt to. so basically use 2.5 at own risk at moment. What else should be talked about?
I am thinking that on 800k and 32mg images i will make a dir called /opt/prodos and place in it all 3 current versions prodos.203tc, .fx .fx.paked and put in User Guide that people can try them all and we will put in readme announcing Fx, announce tc at same time and say they should test all
## Overview
I am going to put some big warning in doc that says "any new Version of ProDOS, be it FX or 2.5" needs to be thoroughly tested and should not be used on volumes that have not been backed up or contains valuable data" or something." and further I think we need some BOLD warning that making FILE file (even by accident) in a dir can make a vol permanately unavailable for access under GSOS (unless we change this, which of course I am pushing for)
you should do a comparative table between 203/FX/2.5
list file sizes of various prodos and paked version
Technical documentation for ProDOS can be found **[HERE](/https://prodos8.com/docs/)**.
### ProDOS 1.0
https://prodos8.com/releases/prodos-10/
Original Release of new Apple II operating system from Apple that features:
- ProDOS runs up to eight times faster than DOS when accessing 5.25” disks.
- Support for a hardware clock has been added, allowing file date and time stamping.
- Hardware interrupts are supported.
- Memory can be protected from being overwritten by the actions of ProDOS.
### ProDOS 2.03
https://prodos8.com/releases/prodos-203/
This is the final release of ProDOS from Apple Computer.
### ProDOS 2.03tc
this version of ProDOS includes updated TCLOCK year table to year 2023
The ProDOS 2.03tc version is included on the 800K media images listed above and provides the maximum compatibility with existing systems.
### ProDOS.FX:
FX supports extended syntax for filenames
1st char in . _ a-z A-Z
char 2-15 in . _ a-z A-Z 0-9
"Faster, eXtended"
How is it faster?
redundant read removed at boot.....
optimized XRW planned
size is lower...so helps fast booting
if you want to keep your ProDOS volume still readable from 203.....no DUP files....and no extended syntax files (.profile...etc...)
and no /lowercasevol
2.5 has same limitation but only because they do /lowercasevol
they dont do case sensitivity nor extended syntax
because they implemented case sensitivity differently and they hit many imcompatibilites
removed support for machine < //e Enh ROM
remove support for machine < 128k
remove 40col Quit code
removed relocator and added UNPAK code
Enhanced IRQ manager (does NOT support //e OLD roms)
a lot of old code in loader was removed
before prodos ran on 48k ok 64k systerms
so there were a relocator, i removed it
FX supported clocks : NSC, TClock ->2023 & Cotland Clock
FX remap more devs......once i fix bugs for your SCSI board
*more than 203
but different way than 2.5
better support for legacy apps
old IRQ manager also
add a note about FX smaller on disk...only 13k
--->even smaller if paked (what size)
Added NSC clock support
TCLOCK year -> 2023
Added SmartPort remap from any slot to any slot, up to 14 devices
i'm changing lot of thing everywhere so that everything works the same with or without lowercase
so basically, everything in now internally lowercased....if run under 203, prodos make it uppercase
if run under FX, it is now natively case sensitive
so the ruse is:
type everything in your script in lowervcase, including #!/bin/sh
internal SH commads are still CI
so ECHO & echo works
but ls in now lowercase
if under 203
LS works
ls works to
if FX, only ls works
LS = file not found
and in your BUILD scripts:
if 14 dev mounted, /RAM wont install
Added support for "." and "_" in filenames
only restriction is filename 1st char != 0..9
Added lowercase support
Patrick Kloepfer 8:46 AM
On the SP remap… lets say you have a Ramworks III with 512K, an Apple Slinky 1meg in S4, a CFFA in S5 with 8 devices and a MDT with 4 block mode devices in Slot 7. What happens? (that totals 14, but how do you deal with /RAM3 and /RAM4. What happens if same cards but CFFA set to 12 devices? Also, what if 5.25 controller in S6 when cffa set either to 8 or 16.
it remaps where there is room for
if you have 4 devs is S7 and 2 in S6....it will remap 2 extra in slot 7 trying to find room starting at S5, then S4...3...2..1....
if 14 devs already mapped....it wont try to install /RAM3
and you wont be able to install Ramworks' /RAM3
so in the above….4 devs from card in 7, it takes the 2 for 7, now finds room for other 2, looks at 6 sees floppies taking both, moves to 5 (does it take 2 here and force card to fend for itself next or see that 5 is a SP card itself and move on). when either card sees slinky in 4 (as /RAM4 as S4D1) does it take the S4D2 spot that can be mapped? if the numbers would work such that RWIII gets an S3D2, will anything ever get mapped to S3D1 (I think you are saying yes)
if S4D2 is free it will be used by remap....so S3D1....
The ProDOS FX version is included on the 32MB media images which are designed to be standalone bootable images. In addition, there is a very special ProDOS FX PAKED version, that is the same as the standard FX image once running, but the file has been compressed and contains a special loader to uncompress ProDOS as it initializes. This version uses less disk space and is used on 140K media where space is at a premium.
### ProDOS 2.4
https://prodos8.com/releases/prodos-24/
For the first time, the features and improvements of ProDOS 2.x are available on 6502-based Apple ][, Apple ][+, and un-enhanced Apple //e computers.
All Apple II computers with modern USB storage devices or hard drives can now support up to 14 ProDOS volumes per device.
### ProDOS 2.4.1
https://prodos8.com/releases/prodos-241/
ProDOS 2.4.1 is a minor release with bug fixes and updates replacing ProDOS 2.4.
### ProDOS 2.4.2
https://prodos8.com/releases/prodos-242/
ProDOS 2.4.2 is a minor release with bug fixes and updates.
ProDOS 2.4.2 replaces the previous ProDOS 2.4 and ProDOS 2.4.1.
### ProDOS 2.5
https://prodos8.com/releases/prodos-25/
Extended Date format which breaks date display in dir listings in A2osX (and BASIC.SYSTEM).
work with the 8 drives per slot but mapping will be off (show multiple d1 and d2) commands like format will have a problem (well format will work but may not format the volume you intended) supporting up to 37 drives.
You get multiple reseeks on drives when doing certain commands, most notable if you have real floppy drives present.
51-file limit on root directory removed (not tested with A2osX yet).
lowercase, fully supported in A2osX.
### ProDOS 16 / GSOS
ProDOS 16 / GSOS are versions of the ProDOS operating system that run only on Apple //GS computers. At this time, A2osX is not supported under these operating systems because of A2OSX.SYSTEM's very sensitive IRQ management required by the multitasking multiuser nature of A2osX. To run A2osX on an Apple //GS you must first switch to one of the supported ProDOS 8 versions such as the supplied ProDOS 2.03tc or ProDOS FX.
## Requirements
ProDOS 8 requires 64kB of memory to run. The original ProDOS (8) 1.0 through 1.0.2 requires only 48kB for the kernel, but nearly all programs, including the BASIC.SYSTEM needed to use Applesoft BASIC, require 64kB, making a 48kB system useless for ProDOS as a practical matter, and support for 48kB machines was removed in version 1.1.
ProDOS 8 version 2.x requires a 65C02 or later (65802, 65816) CPU. ProDOS 8 2.x runs in 64kB, but the utility programs on the system disk require 128kB. Systems with a 6502 CPU instead of a 65C02 must use ProDOS 8 versions prior to version 2.0.
ProDOS 8 2.4 and 2.5 removes the 65C02 requirement and will run on all Apple II computers with at least 64 KB of RAM, although BASIC.SYSTEM still requires an Applesoft ROM.
ProDOS 16 requires an Apple IIGS.
ProDOS 2.03tc has the exact same requirements as ProDOS 2.03 since its only difference are the eight patched bytes to the date/year table.
ProDOS FX requires a 64KB 65c02 or later CPU. ProDOS FX will not run on a Apple ][ or ][+. Note, however, that A2osX itself requires a minimum of 128kB to operate.
## License
A2osX is licensed under the GNU General Public License.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
The full A2osX license can be found **[Here](../LICENSE)**.
## Copyright
Copyright 2015 - 2020, Remy Gibert and the A2osX contributors.