Macintosh IIci - Installing on a non Apple disk

The Apple setup tools for System 6.x/7.x only support Apple firmware disks (all of which are long dead, or extremely expensive). If you want to use a cheap ultrawide Seagate or Hitachi SCSI drive… or a modern solid state replacement like an AztecMonster or SCSI2SD, you need to fool the Apple disk utilities into believe they're running on a bonafide Apple drive.

• Boot from a bootable System 7 installer, in my case a System 7.6 install CD
• Insert a patched copy of the Apple Disk Setup tool
• Initialise and partition the drive
• Reboot and boot from whatever install medium you intend to use; System 6, 7 or 8.