I had to give NAS-DOS a page of its own because I happened to have these pictures. š
When Lucas Nascom produced their disk system they decided to use a version of DCS-DOS, originally produced by Dove Computer Sevices as an upgrade to D-DOS on the Henelec disk system. Their version was similar to DCS-DOS 2 (an upgrade to the original DCS-DOS), but modified to use a proper control board rather than connection via the PIO.
As you can see from this photograph, no expense was spared on an inspiring cover design for the NAS-DOS documentation. š
If you would like to read it, the full text is Here
nascom.info 