Amiga Forever 3.X ROM Improvements
Q: What are the differences between Cloanto's 3.X ROMs, and the original versions and updates released by Amiga?
The 3.1 ROM, initially released in the CD³² hardware in 1993, was the last Amiga ROM version released by Commodore/Amiga.
The 3.X series by Cloanto, first released in 1999, aims to remain as true to the original as possible while merging some essential updates, the most notable of which being the ability to boot from "large" hard disks. This was originally released by Amiga (under the ESCOM and Gateway ownership) as a "SetPatch", while the Amiga Forever ROM distribution made it officially possible to use it as a native ROM, without requiring a reboot.
For maximum compatibility with the existing code base, the original binary code was largely preserved, limiting recompilation and thus the potential for new bugs to a minimum.
Since the initial release, further 3.X ROM improvements followed in 2006, 2014 and 2016. All were designed for use across the Amiga Forever product series, i.e. including both emulation and Classic Support scenarios ("real" Amiga hardware).
The 3.X ROMs have a size of 512 KB, and are therefore compatible with all Amiga models except for the Amiga 1000. In order to make room for the enhancements, the 3.X ROMs employ the same technique used by Commodore for the 4000T ROMs, i.e. ROM space was freed by moving workbench.library out of the ROM. This means that a "Libs/workbench.library" file must be present on the boot disk, as detailed below.
The current 3.X ROM (45.066) builds on the original 40.068 ROM components, featuring the following improvements:
- Official Amiga patches (e.g. large disk support)
- scsi.device and exec.library updates by Alexander Benedictov, Chris Hodges, Heinz Wrobel, Jeff Weeks and Toni Wilen
- expansion.library fixes and 68060 patches by Jeff Weeks
- Ranger memory detection routine replacement by Henryk Richter
- FastFileSystem fixes by Etienne Vogt
- mathieeesingbas.library fixes by Harry "Piru" Sintonen
- Fix to floppy drive issue affecting some systems in version 45.061
Support for Disks Larger than 4 GB
The scsi.device updates included in the 3.X ROM make it possible to boot from disks larger than 4 GB. Additional elements, such as FastFileSystem 45.9 and Installer 44.10, are included in the Classic Support Workbench 3.1 distribution, and complement the ROM-based enhancements.
For maximum compatibility, the Amiga boot partition should be the first partition of a disk, and it should not be larger than 4 GB. In order to remain compatible with older software that uses 32-bit values to measure disk capacity, a maximum partition size of 2 GB is recommended.
For additional information on support for disks larger than 4 GB, see Amiga Forever Workbench 3.1 Improvements.
Because workbench.library is not part of 3.X ROMs, a "Libs/workbench.library" file, as included in the Classic Support Workbench 3.1 set by Cloanto, must be present on the boot disk. This requirement is in common with later 3.1 ROMs by Commodore and ESCOM, as used with the Amiga 4000T model.
For additional information on adding the "workbench.library" file (available here), see Amiga Forever Workbench 3.1 Duplication Instructions.
Older versions of the SetPatch command may not have been designed for use in combination with newer ROMs. Such versions of SetPatch may either fail to work properly with 3.X ROMs, or unnecessarily slow down the boot process and waste memory by loading ROM modules that don't need to be updated.
In these cases, a simple change to the Startup-Sequence helps detect and avoid updating 3.X ROMs. The SetPatch command itself is still required, for example, to enable AGA chipset features.
Open S/Startup-Sequence and look for the following line:
Replace it with:
C:Version >NIL: exec.library 45 20 If WARN C:SetPatch QUIET Else C:SetPatch NOROMUPDATE QUIET EndIf
The NOROMUPDATE option was introduced in SetPatch version 44.13. If used with previous versions, it will give a "wrong number of arguments" error. A version of SetPatch that supports the NOROMUPDATE option is available here.
Such an updated "Startup-Sequence" file is already included in the Classic Support Workbench 3.1 set, where it does not need to be edited manually.
Each 3.X ROM set comes with a license key that can be used to download the ROM or the "workbench.library" file for installation or recovery purposes. To register for support, please refer to cloanto.com/genuine.
|Products:||Amiga Forever, Amiga Forever Classic Support|
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