On Tue, 18 Nov 1997, Richard Cini wrote: Well... the 'standard' H-11 had a DEC 11/03 (quad wide) cpu card in it, and from there on it was full of Heath cards that were just different enough to make life real interesting. It does however have a standard 18 bit backplane, so many folk installed more 'normal' DEC cards as time went on. The Heath disk system did have the virtue of being able to format (really) blank disks, unlike the DEC floppy sub-system, and was RX-01 media compatable in one mode, and also added a Heath double-density mode which was not really compatable with much of anything else... (AIR) Heath distributed a slightly mutated (drivers mostly) version of RT-11 that they dubbed 'HT-11' to support the Heath peripherals. If you are getting the software, it should not be a problem. The H-27 disk sub-system is *heavy* (I've got one in the collection) -jim --- jimw(a)agora.rdrop.com The Computer Garage - http://www.rdrop.com/~jimw Computer Garage Fax - (503) 646-0174