NitrOS9 in ROM
(development system.)

The 40K area of NVRAM immediately after the System Settings NV RAM is reserved for a OS9 "in ROM" boot image.The image can be booted from the virtual coco that has been assigned U9: and defaults to using the Disk specified in Settings ROM as /dd. You should backup your system copy before playing with this one way is U prompt BACKUP NVR command another is to boot a NitrOS9 with a /ud9 and a /x1 device descriptor dmode and format the drivewire image in x1 so that it is single sided with eight cylinders and twenty (ie. $14) sectors per track on all tracks. Then the NitrOS9 command backup /ud9 /x1 will create the backup be sure to check that drivewire has saved it on your server before changing the original.

Although this /ud9 contains an OS9Boot file an image of this file is not boot-able from another coco or standard emulator because no kernel track is available if you cobbler a  /ud9 drive image you get the following error.

Warning - file(s) present
on track 34 - this track
not rewritten.

However as long as the NitrOS9 you are running has the correct kernel the drive image will boot when copied  to a CoCo5's U9: drive with the os9 backup command. After Booting a compatible OS9 from drivewire This would be done as follows note user input shown in bold text below.

{Term|02}/DD: dmode /ud9  cyl=8 sid=1 sct=14 t0s=14
{Term|02}/DD: format /ud9
COLOR COMPUTER FORMATTER
Formatting drive /x1
WARNING: You are formatting a HARD Disk..
y (yes) or n (no)
Ready?  y
WARNING: You are formatting a HARD Disk..
Are you sure? y
Both PHYSICAL and LOGICAL format? y
Disk name: OS9ROM
Physical Verify desired? y
000 001 002 003 004 005 006 007
Number of good sectors: $0000A0
{Term|02}/DD: cobbler /ud9

Now that you have the new image saved you can use the command OS9 in BASIC from the virtual CPU to which U9: is attached to boot the "In ROM" OS9.