From what I can tell, the Corvus was an external hard drive that connected to a number of machines over some kind of network. I never used the Corvus stuff but I think it must have been relatively common at one time. I've seen a number of Corvus cards floating around. I've also seen one or two of the drives. I had/have some Corvus PCs cards and I did know where there were a couple of thin manuals for it. Joe At 06:45 AM 2/16/01 +0100, you wrote: one move

"Iggy Drougge" <optimus(a)canit.se> wrote: I'm not sure I would call it widespread, but it was significant enough that the DEC marketeers working on the Pro 350/380 saw it as something they would have to compete against with Ethernet. (Ref: presentation about DEC's entries into the PC marketplace, at the Computer Museum History Center sometime in 1997; sorry, don't have any other details handy at present.) In the mid-1980s and into the 1990s there were a number of competing physical network media: Ethernet, ARCNET, IBM token-ring, Proteon token-ring (Pronet), Starlan, Omninet and other things too. Some of the other physical media had as a selling point that they were cheaper to install than Ethernet: cheaper network interface adapters and cheaper cabling. Anyway, back to Corvus. Corvus got its start selling parallel-TTL-interface hard disks for the Apple ][. A hard disk was more expensive than an Apple, so they also sold a multiplexer option that allowed the connection of up to eight computers' controllers to one hard disk, and IIRC you could have two multiplexers between a computer and its hard disk so you could actually have 64 computers on one hard disk. Corvus also made hard disk controllers for other hardware: I know I've seen one for S-100, and have read of one for the PDP-11, and that there were others. Same parallel interface. Now, imagine a sort of star-topology network strung together with 34-pin ribbon cable. Imagine distance limitations, and imagine stringing all that cable and trying to keep it from turning into a tangle as computers get moved around. Not fun. So the folks at Corvus came up with Omninet, a 1Mbit/s twisted-pair serial bus (using RS-422 levels) that could support a couple hundred addressable devices. You could either access your parallel hard disk via a computer that was attached both to it and to the Omninet, or via an Omninet Disk Server, which was really a dedicated computer with an Omninet interface and a Corvus parallel hard disk interface. Corvus made Omninet interfaces for a number of different computers. Apple ][, IBM PC, DEC Rainbow, Apple Macintosh, and I don't remember what else; those are the ones I've seen recently. They also designed an Omninet interface into their microcomputer offering, the Corvus Concept. Omninet cabling was cheap: a single twisted pair bus. Connecting to it was cheap: you could buy the official Omninet tap box and node cable (two wires terminating in a mini phone jack) or you could just splice your node cable (two wires) to the two wires of the two wires of the bus pair. Omninet bus termination was a resistor across the ends of the pair. There was also a later Omninet II network that ran at 4Mb/s, but I think that involved a two- or three-pair bus. The only interfaces I've ever seen for Omninet II were IBM PC ISA cards. NEC also had a preliminary data sheet for an IC (uPD72105) that did Omninet in their 1987 Microcomputer Products data book, volume 2. -Frank McConnell