The procedure of building an OS 3.9 kickstart ROM can be summarised with the following steps: The list mentioned in the following table also includes 3.1 ROM modules that have no reason to be there, however, they do no harm by being there and give you a clean overview of what your ROM will be like when the accelerator substitutes the ROM modules. To conclude, the best option is to use the accelerator features and make your accelerator patch the ROM on the fly by injecting individually updated ROM modules.

In other words, you will at some point want to go back to 3.1 to be able to run a game or a program that may behave differently due to the various 'updates' that have been added in the semi-official 3.9 AmigaOS. Even worse, accelerators cannot kick a ROM file that exceeds these limits either - even if you are kicking just a file and are not burning a physical ROM chip.įrom a different perspective, you do not really want a 3.9 kickstart ROM because you want your Amiga to be most compatible with the software that has been optimised to run on previous versions of Amiga OS. Unfortunately, the Amiga has hard-limitations on how large (in size) a ROM can be - for instance, the workbench.library from OS 3.9 is conventionally left out of a 3.9 kickstart ROM because it would make the ROM too large to boot. Substituting ROM modules, and, more generally, updating the kickstart modules can be performed in two different ways:Ĭreate a custom kickstart using Remus and either burn a physical ROM chip or use the accelerator to kick the resulting file. The NOROMUPDATE flag tells SetPatch to not override modules that are to be found in the ROM and should be used, for instance, if BlizKick is called before SetPatch.įortunately, RAM is, by today's market, rather cheap (even for an Amiga accelerator) such that there is no need to be conservative about updating and substituting ROM modules using your accelerator. When SetPatch runs, it substitutes some ROM modules with updated ROM modules from Amiga OS 3.9.Ĭommonly, when an accelerator is present that allows mapping the Amiga ROM into fast RAM and loading custom ROM modules using the accelerator built-in features - for instance, BlizKick for Blizzard accelerators, the SetPatch command in the startup sequence ( S:startup-sequence) is run with a flag that prevents SetPatch from overriding any modules loaded by the accelerator:

Updating the kickstart when running Amiga OS 3.9 is performed by the tool SetPatch that is called at the very beginning of the Amiga startup sequence ( S:startup-sequence).

Improving amiga os 3.9