Boot an Amiga from a disk image embedded into the ext. ROM
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ROMDISK/s added romdisk create tool Jul 9, 2016
doc added docs Jul 27, 2016
src fixed boot prio Jul 27, 2016
.gitignore adjusted .gitignore Jul 27, 2016
Makefile add mkromdisk to dist Jul 27, 2016 added docs Jul 27, 2016
mkromdisk added docs Jul 27, 2016 improved build system Jul 21, 2016

Project romdisk - Boot your Amiga from ROM

Written by Christian Vogelgsang under the GNU Public License V2

This projects provides a romdisk.device you can place in an Amiga Kickstart or external ROM. It will autoboot a disk image that is stored next to the device directly in the ROM. You can either store a raw OFS /FFS disk image (ca. 500 KiB size) or a compressed image that holds up to a whole Amiga disk (ca. 880 KiB size). While the raw storage is ultra fast, the compressed images allow you to deploy whole disks into ROM.

Additionally, a tool for modern systems is available that allows you to create those romdisk image easily from existing .adf disk images or from a directory of files.


Create boot ROMs for

  • Diagnosis
  • Network Boot
  • Quick Startup
  • Device-less Amiga Setups
  • stripped down Amiga OS ROMs that do not use any external devices during boot (simplifies emulation)


  • use them in your favorite Amiga emulator
  • soft-kick'em in your accelerator card
  • flash or burn them to ROMs


  • Store raw or compressed disk images
  • Compressions supported:
    • Deflate Compression from ZLib
    • RNC Compressor (Rob Nothern Computing)
    • LZ4 Fast Compression
  • Autoboot on OS 2.x and 3.x
  • Configurable image geometry, boot priority
  • Python tool mkromdisk to create image file from disk images or directories
  • Amiga device with source that can be cross-compiled on modern systems
  • A drop-in replacement variant for trackdisk.device to have a very compatible DF0 device


  • Amiga OS 2.x or 3.x and real/emulated classic Amiga m68k system
  • Python 2.7 for host tool
  • amitools installed for xdftool, romtool, and vamos
  • ppami.exe Amiga tool from RNC ProPack to use RNC Compression
  • lz4 tool from to use LZ4 Compression
  • Cross compilers from amigaos-cross-toolchain to build device from sources


Here is a quick wrap-up on how to create and run a ROM with a romdisk:

  • First create a Kickstart ROM that supports an external ROM with additional 512 KiB storage. We use amitool's romtool to convert a A1200 Cloanto OS 3.1 to support 1 MiB ROMs:
romtool patch -o kick.rom miga-os-310-a1200.rom 1mb_rom
  • Now run romdisk's mkromdisk tool to create a romdisk image from a disk image. We use the Workbench 3.1 disk from Cloanto's Amiga Forever distribution here (its called amiga-os-310-workbench.adf):
./mkromdisk -i amiga-os-310-workbench.adf -f dflt wb31.rodi
  • Finally, create an external ROM image with romtool that contains the romdisk.device (release version) and your romdisk image wb31.rodi:
romtool -v build -o ext.rom -t ext romdisk.device_rel wb31.rodi
  • Voila! Your ROM set is ready to be run. You can either use the two files directly (e.g. in your emulator) or combine them to a single 1 MiB ROM file if your soft-kicker needs that:
romtool combine -o 1mb.rom kick.rom ext.rom
  • Run the ROM set in the FS-UAE emulator with a configuration like this one (e.g. in a test.fs-uae file):
amiga_model = A1200
kickstart_file = kick.rom
kickstart_ext_file = ext.rom

If you run the emulator it will boot the Workbench directly from ROM...

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