We used to do stuff similar to this at Acorn in the 80's, both for multi-system and for the same system but with both 40 and 80 track drives. I vaguely remember that one key feature was that one system numbered tracks from 1 upwards and another from 0 upwards, allowing for two separate directories. There were a lot of tricks that I've forgotten now. You could sometimes fit more than 80 tracks on a floppy. And then there was the 9 vs 10 sectors per track issue. I was only peripherally involved in this area, but we had a couple of guys who knew it inside out. In fact our guys who wrote our disk protection mechanisms were damn good at breaking everyone else's too:-) I remember tricks with using different FDC controllers and even at one point sticking pins into floppies at exactly the right spot to force a hard error on a sector...
Process separation is a good idea, but the practice is somewhat different - my wife installed Chrome, and whenever it crashes, which is quite often, it BSOD's her computer, causing a reboot!
Interesting article, except N-BRAIN *doesn't* offer an open source (or even no cost closed source) version of UNA. At their website following the given link, all you can find is a single-user trial, and a single-user trial isn't much good when the main product is a realtime collaborative editor.
Possibly the press announcement got ahead of the web site guys and the open source version is coming shortly, but it's not there today.
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EMAS, and Multics. Two major operating systems that don't run anywhere, even under emulation.
We used to do stuff similar to this at Acorn in the 80's, both for multi-system and for the same system but with both 40 and 80 track drives. I vaguely remember that one key feature was that one system numbered tracks from 1 upwards and another from 0 upwards, allowing for two separate directories. There were a lot of tricks that I've forgotten now. You could sometimes fit more than 80 tracks on a floppy. And then there was the 9 vs 10 sectors per track issue. I was only peripherally involved in this area, but we had a couple of guys who knew it inside out. In fact our guys who wrote our disk protection mechanisms were damn good at breaking everyone else's too :-) I remember tricks with using different FDC controllers and even at one point sticking pins into floppies at exactly the right spot to force a hard error on a sector...
Process separation is a good idea, but the practice is somewhat different - my wife installed Chrome, and whenever it crashes, which is quite often, it BSOD's her computer, causing a reboot!
Interesting article, except N-BRAIN *doesn't* offer an open source (or even no cost closed source) version of UNA. At their website following the given link, all you can find is a single-user trial, and a single-user trial isn't much good when the main product is a realtime collaborative editor. Possibly the press announcement got ahead of the web site guys and the open source version is coming shortly, but it's not there today.