Kickstart Roms Explained

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Compatibility, versions and emulation requirements.


Kickstart Roms, what are they?

Kickstart 3.0 Roms
The Kickstart Roms are rom chips mounted on the Amiga motherboard and contain the core system code/files required for the system to load and run any Amiga software. Without the Kickstart roms an Amiga is useless.

As Amiga development progressed newer versions of the kickstart roms were released. These were tied in with each version of Workbench, with each version of Workbench requiring the same version of kickstart roms in the system for it to work.

The very first Amiga released in 1985, the Amiga A1000, came with Kickstart version 1.0, but this Amiga didn't have this on rom chips, instead booted the code into memory from a Kickstart floppy disk. You needed to do this every time you rebooted the system and then swap the disk for one with the actual software you wished to run, such as the Workbench OS disk or a game. This did have the advantage of allowing newer kickstart versions to be easily used on the system by obtaining the latest version. But having to load it from floppy disk every time was tiresome after a while.

After the A1000 came the A2000, and this was the first to have the kickstart files loaded onto rom chips. This meant that you didn't first need to boot up a kickstart disk, but could instead stick a software disk into the drive and switch on the system to boot directly into the software, making life much easier. The A2000 first came with Kickstart 1.2, and was later updated with Kickstart 1.3.

The same was true of the A2000's little brother, the A500. This also first came with the kickstart 1.2 version and later the 1.3 version.

Kickstart 1.3 is the most compatible version of the rom out of all versions as most games were written for this version of the A500.

After the A500 came the A3000. This was similar to the A1000 in that it also didn't have actual kickstart roms, but this time the Kickstart was loaded from the internal Harddrive. This was by far the best design as it meant different kickstart versions could be swapped very easily with a software update. The A3000 was the first Amiga is use an updated version of the Amiga's custom chipset, called the Enhanced Chip Set (or ECS for short) and this came with kickstart 2.04, which was a huge upgrade over the older 1.X versions, and with it Workbench 2, which also improved the Amiga OS greatly.

In general most games that ran on an A500 with kickstart 1.3 would also work on a system with kickstart 2.04 roms. But some older titles didn't work due to changes in the custom chip set and the kickstart roms.

After the A3000 came the A500 Plus. This looked the same as the A500 but had the same enhanced ECS chipset as the A3000, but with the kickstart 2.04 roms now loaded from rom chips. This replaced the original A500 and was as popular.

Next the A600 replaced the A500 Plus. Nearly identical in hardware with the same ECS chipset, and a slightly updated kickstart 2.05 which added support for IDE harddrives and PCMCIA cards. The kickstart 2.04 and 2.05 versions are nearly identical so anything running on one should run on the other.

After this the biggest change in Amiga development happened. The Advanced Graphics Architecture chipset, or AGA for short. This was a huge update for the Amiga and added a lot of new features included 256 colour graphics and a much improved Workbench 3.0 OS and Kickstart 3.0 roms.

The A4000 was the first AGA Amiga to include the kickstart 3.0 roms and many older Kickstart 2 and 1.3 games would not work on the new chipset and kickstart roms.

After this the A4000's little brother, the A1200 was released, using the same kickstart and AGA chipset and sharing the same compatibility issues. But the benefits of the new AGA chipset and kickstart 3 roms greatly out weighed the compatibility issues.

Finally we have Kickstart 3.1. This was a big update to kickstart 3.0 code which fixed many bugs in the original 3.0 roms, but in use not much was actually noticeably different. The newer A1200's and A4000's made had these roms as standard but the older 3.0 based AGA Amigas needed to be upgraded. The 3.1 roms were also included as standard in the CD32. And the 3.1 roms still remain the newest version available.

Kickstart versions summary

Kickstart version Kickstart revisions Max Workbench version usable. Available for Amiga models Date released ROM size Additional Information
8KB Bootstrap A1000 1985 8 KB Only present in A1000. Shows Amiga Kickstart screen, loads full Kickstart from disk into special area of RAM.
1.0 NTSC only 1.0 A1000 1985 256 KB No version information was recorded in the Kickstart ROM
1.1 31.34 (NTSC)
32.34 (PAL)
1.1 A1000 1985 - 1986 256 KB Very buggy Workbench! Seperate PAL & NTSC releases
1.2 33.166+
1.3.4 A1000*, A500, A2000 1987 256 KB Autoconfig present in ROM, but cannot boot Hard Drive.
Early A500s had 1.2 and RED power LED.
1.3 34.5 1.3.4 A1000*, A500, A1500, A2000, CDTV, A3000 1988 256 KB Autoconfig now fixed, first Kickstart release that can boot from Hard Drive. Most common ROM versrion for A500s
1.4 Alpha
1.4 Beta
1.4 Alpha
1.4 Beta
A3000 1989 256 KB Used by many early A3000s as an internal bootstrap ROM, which then boots 1.3 or 2.04 depending on what you select.
2.0 36.143 2.1 A3000 1990 512 KB Early revision of the 2.0 ROMS, contained some bugs and was quickly replaced by 2.04
2.04 37.175 2.1 A500, A500 Plus, A1500, A2000*, A3000, A3000T, some CDTVs 1990 512 KB Some late A500's manufacutred in 1990/91 came with 2.04 instead of the usual 1.3
2.05 37.299
2.1 A600 1991 - 1992 512 KB v37.300 revision required or above to boot from internal HDD and use PCMCIA slot.
3.0 39.106 3.1 A1200, A4000 1992 512 KB workbench.library missing from A4000's 3.0 ROM. Is installed in LIBS: folder for A4000 to fix this. No PCMCIA support in A4000 version.
3.1 40.55 3.9 A3000*, A4000 1993 512 KB
3.1 40.60 3.9 CD32 1993 1 MB One ROM chip, also contains CD32 Extended ROM
3.1 40.62 3.9 A3000* 1993 512 KB
3.1 40.63 3.9 A500*, A500 Plus*, A600*, A1500*, A2000* 1993 512 KB
3.1 40.68 3.9 A1200, A4000 1993 512 KB
3.1 40.70 3.9 A3000*, A4000, A4000T 1994 512 KB
3.9 45.x 3.9 A1200*, A4000*, A4000T* 2006 512 KB A custom made scene ROM for Workbench 3.9. Included KS3.1 files + 3.9 AmigaOS ROM Update. ROM can be built and tailored to exact system needs, leaving out device libraries that are not used, and adding others that are needed.

* Only available as an upgrade for this Amiga model.

+ A1000 Only.

Kickstart Revisions: Different kickstart revisions exist for each version of Kickstart ROM. Newer revisions fix bugs and missing code. For example the earliest A600 2.05 rom, revision 37.299, was missing all support for the IDE and PCMCIA ports. Some revisions of a rom may only work in a specific Amiga model to support unique hardware features.

Kickstart updates

Kickstart 3.1 Roms inside A1200

As newer versions of the Amiga kickstart roms and the associated Workkbench OS versions were released, the ability to upgrade the older models of Amiga to the latest version of kickstart and Workbench were offered for more models.

With the A1000 and A3000 this just involved getting hold of the newer kickstart on floppy disk, but for all other Amiga models this required a new set of Kickstart rom chips. These are socket mounted on the Amiga motherboard, as shown in the picture to the right, and are not hard to change. Just open up the Amiga case, remove the existing chips, and insert the new ones.

Therefore any Amiga can be updated to run a newer version of kickstart rom and related Workbench OS version (The A1000 didn't see versions of Kickstart from 2 onwards due to hardware limitations). So you could for example update an Amiga A500 to kickstart 3 and run Workbench 3 on it.

Upgrading older Amiga models with newer kickstart versions means being able to run the newer version of Workbench and therefore all the applications and utilities written for it. But you do have to remember that the rest of the hardware in the system will remain the same, so features of a newer version of Workbench that require the features of a newer custom chipset will still be missing. For example higher colour modes on the A1200 would be missing when Workbench 3 is running on an A500 with an older chipset. It also means that for example a game written fro Kickstart 3 Amiga's, but utilising the A1200's AGA chipset will not run on an A500 with the kickstart 3 roms, because the rest of the A500 will still be the same as it was before, with the Original Chip Set (OCS).

As already mentioned Kickstart 3.1 is the latest version of the kickstart rom and an Amiga requires this in order to run all of the newer versions of Workbench including Workbench 3.1, 3.5 and 3.9. If you wish to run these newer versions of Workbench you will need to upgrade your kickstart roms to 3.1.

Upgrading to Kickstart 3.1 ROMs

Most Amiga models can be upgraded to the latest Kickstart 3.1 rom chips, so that you can take advantage of the newer Workbench 3.1 OS and the extra features 3.1 allows. However you do need to obtain the correct Kickstart 3.1 rom chips for your model of Amiga because not all kickstart rom chips will work in all models of Amiga.

This list shows you which Kickstart 3.1 roms will work with each model.

Single Chip Kickstart 3.1 ROMs

The Kickstart ROMs for these models are interchangeable between each other.

  • A500
  • A500+
  • A600 (including A600HD)
  • A1500
  • A2000

Two Chip Kickstart 3.1 Roms

The two chip Kickstart ROMs for these models are not interchangeable between each other, and each will only work with their specified Amiga model. You cannot use an A1200 3.1 rom in an A4000 for example. You need to source the specific version of the 3.1 ROM for the specific model you own.

  • A1200 (inc. A1200HD)
  • A4000
  • A4000T

Amiga models that have special ROM chips arrangements

  • A3000 (& A3000T) - use ROM tower! Some early models have Kickstart 1.4 Alpha 15 ROM and boot 1.3 or 2.04 from Hard Disk, others have 2.04 ROM.
  • CD32 - can only take specific CD32 3.1 ROMs - it is basically Kickstart 3.1 with CD32 Extended Kickstart ROM.
  • CDTV - a bit of a strange setup - some units can take an A500/A600 2.04 ROM, but not all of them. Also has CDTV Extended ROM. The CDTV Extended ROM is also present in the A570 CD-ROM drive add-on for A500/A500+.
  • A1000 - uses an 8KB Boot ROM, which prompts for Kickstart disk and in turn loads Kickstart into a special 256KB area of memory - technically this memory is WOM (Write Once Memory) and the Kickstart stays there until power-down. Because it's only 256KB you can only use the following ROMs: 1.0, 1.1, 1.2, 1.3 and possibly 1.4 Alpha (This needs to be verified).

Hopefully this will help all those thinking of upgrading their Amiga to Kickstart 3.1. Please ask on the classicamiga forum if you have further questions.

Why upgrade from Kickstart 3.0 to Kickstart 3.1?

If you own an A1200 or A4000 with Kickstart 3.0 Roms installed, then you might wonder what the advantages are, and why it is worth upgrading to the newer 3.1 roms. Here are some of the main changes 3.1 offers over 3.0.

  • 3.0 cannot run AmigaOS later than 3.1 (it doesn't support loading in modules from AmigaOS updates like 3.1 does)
  • 3.1 contains many bug fixes to the libraries both internally and on the disk
  • 3.1 is more up-to-date
  • 3.1 supports the Akiko chip when used on a CD32
  • 3.1 supports the extra CD32 libraries that are built into ROM (namely lowlevel.library and nonvolatile.library)
  • 3.1 contains minor improvements to RTG handling
  • 3.1 contains the additional datatypes: ANIM and CDXL
  • 3.1 introduces a small delay whilst checking for hard drives. This gets around the old 3.0 bug whereby a hard drive is not always recognised from cold boot.

Software compatibility

Software written for an Amiga with one Kickstart version is not guaranteed to work on all other Amigas with different kickstart versions. Obviously software written specifically for a newer version will not run on an older one. So software written for Kickstart 2 will not run on 1.3 etc.

The opposite is a bit more complicated. If the programmers wrote their programs correctly then the majority of the time software written for an older version of kickstart will work on a newer one. So a game written for a Kickstart 1.3 Amiga will run on a 2.04 based Amiga most of the time. This isn't always the case though because of the differences between the kickstart versions, but also because the rest of the Amiga hardware was updated between models so this can have an effect on some software working.

The biggest of these was the AGA chipset and Kickstart 3.0 version. Because the newer Amiga's using these chips also had a different faster central processor, and more chip ram it meant that many game from older 1.3 and 2.04 Amigas would not work. There were ways to get most of these games to eventually run on an A1200 and we will cover this in another guide.


As I've already mentioned, the Amiga Operating System Workbench required the same version of kickstart rom as the OS version to work. So Workbench 1.3 ran with Kickstart 1.3, Workbench 2.04 with Kickstart 2.04, Workbench 3 with Kickstart 3.0 etc...

But in contrast older Workbench versions will boot up fine on a system with newer kickstart roms, but because a lot of the OS is built into the rom itself, including many system libraries, it means the older versions will look more like the newer OS than they did on their own older kickstart version.

Finally emulation

To emulate the Amiga the emulator needs a copy of a kickstart rom as a rom file for the emulation of the Amiga to work. No Amiga emulator comes with these kickstart rom files included because they are the one part of the Amiga that is still under copyright, and it is illegal to distribute the roms freely.

A full set of Amiga kickstart roms can be purchased as part of the Amiga emulation package, Amiga Forever. These are officially licensed roms, and more information can be found at the Cloanto website

With a set of Amiga Kickstart rom files you will be able to emulate any of the real models of Amiga. Therefore allowing you to chop and change between then to run software compatible with each. This is especially useful for Games, where a kickstart 1.3 rom would be needed to run A500 OCS games, kickstart 2.04 to run A600 ECS games, and kickstart 3.0 or 3.1 to run A1200 AGA games.

When emulating Amiga games are normally classified based on the hardware they were compatible with. This includes the kickstart version, but also the version of custom chipset. This can be OCS (Original Chip Set), as found in the A1000, A500 and A2000, the ECS (Enhanced Chipset), as found in the A500 plus, A600 and A3000, and AGA (Advanced Graphics Architecture) as found in the A1200, A4000 and CD32.

Try the following configurations in the Amiga emulator you are using for the highest compatibility with games.

For an A500 OCS game use the 1.3 Kickstart Roms with 512KM Chip ram and 512KB Fast Ram. For an A600 ECS game use the 2.04 Kickstart Roms with 1MB Chip Ram. For an A1200 AGA game use the 3.01 Kickstart Roms with 2MB Chip Ram.

If these settings don't work with a game then try changing some of the ram amounts.


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