Kickstart ROM

A ROM chip found in Amigas.

This chip has the code that some parts of the operating system need. None of my references seem to tell exactly which parts, but I think at least the basic OS code required to boot the OS from disk is there. Also probably some "intensively used" things.

In general, I've noticed, you need Kickstart ROM version equal or greater than AmigaOS/Workbench version to run the latter.

You need to copy the contents of this ROM to file to use an emulator such as UAE; Copies of the ROMs can also be found from Amiga Forever.

The Kickstart ROM contains the whole basic operating system of an Amiga. The 1.x release versions (versions 34.xx) of Kickstart were stuffed into 256 kB ROM chips (and into floppy disks for A1000). Release versions 2.xx (36.xx) and 3.xx (40.xx?) are 512 kB. Here is what is needed for a basic CLI window (and some information about which library takes care of what):

• Exec (memory allocation, interrupts, multitasking, library handling)
• DOS (file system (read/write) handling)
• Intuition (screens, windows, IDCMP)
• Graphics (graphics, font handling)
• other miscellaneous ROM resident libraries such as console.library
• trackdisk.device and other ROM resident #?.devices
• disk.resource and other ROM resident #?.resources
• ROM resident handlers (includes at least one file system)
• all the other little bits like AutoConfig routines (Or do you want to mount all the external floppy drive units by hand?)
• either ROM or disk resident command software (I'm quite sure that you want to do something else than just resize and move the window around.)

All that (excluding disk resident command software) is resident in the Kickstart ROM and all the ROM resident libraries, commands, devices, etc are always available. If you wish to use Workbench, you need LoadWB and two disk resident libraries, icon.library and info.library. (1.x release versions need them on disk. Newer Kickstarts might have those libraries ROM resident.)

Some words about the boot process: The AmigaDOS 1.x floppy disk bootblock contains only a few tens of bytes of program code (starts from offset $c) for checking whether dos.library is resident (ie in the memory ready to use) or not. If that library isn't resident, there apparently isn't any sort of complete Kickstart available and the bootblock program returns error code $ff. A1000 with its separate Kickstart disk is a possible reason why the code exists. I think the bootblock code also, when no error is returned, returns an address (dos.library's base address + $16) for the Exec to properly boot from the floppy. ("I think" because I'm not sure why the $16 offset is added to the base address.)