Hi Rich
The mainboard has 4 * OHCI, 3 * EHCI and 1 * XHCI controllers.
A *new* 2Gb USB 2.0 flash drive was used - DFSee was used to create a partition using the full size of the drive.
The USB 2.0 flash drive is inserted into a USB1/USB2 port for attaching or booting - XHCI driver not involved in any way.
AOSBoot, running from the ISOFS mounted 5.0.5 ISO, was used to create the bootable installation drive with the flash drive letter N: and ISO path G:\OS2\ArcaNoae\ArcaOS-5.0.5\ArcaOS-5.0.5.iso as parameters.
The drive can be attached and viewed once created, the ARCAINST.ISO can be mounted using ISOFS and files can be accessed.
Once booted to the Menu for own choices screen it looks like the USB drive becomes disconnected/unattached as the led is no longer illuminated - led is always on when attached, flashes when being accessed.
After the Menu screens, during booting, the led comes on indicating it has been attached - probably. After the call to pmshell.exe the message about the "missing" ISO file is displayed.
It seems to me that the USB drive gets lost after booting to the Menu for own choices screen and fails to reattach correctly. Wonder if it would work if I accepted "Defaults" instead of booting to the Menu...
Gave it a try but no joy.
I then had another think about this problem. At some point the USB drive gets ejected, but not removed, and fails to attach with LVM /REDISCOVERPRM about the start of install. Maybe it is necessary to physically remove the USB drive rather than just using eject.
I tested that idea on my 5.0.4 desktop: I attached the 5.0.5 USB flash drive which became drive N: in the Drives folder, accessed it then ejected it but left it in the usb port. Typed a couple of the above sentences then clicked the Refresh Removable Media icon. The icon flashed, the USB flash drive led illuminated - and no drive N: (next available drive letter) appeared in the Drives folder.
Mystery solved: the ArcaOS install script needs to issue some "Remove USB drive" and "Insert USB drive" messages, pausing the process while it waits for the physical action to complete, possibly "Press a key when ready..." added to the above messages.
Having worked out when to physically remove the usb drive and when to reinsert it again I now have a basic 5.0.5 installation - hopefully I did not miss anything too important by being a little late reinserting USB drive during Phase2 and having to restart Phase2.
Interestingly I did not have this problem on this hardware when installing 5.0.4 from a different USB flash drive.
While I seem to have worked out cause and effect what is the ""undocumented feature" to diagnose this a bit further."?
Regards
Pete