at&t unix pc

On 10/12/10, Steven Hirsch <snhirsch at gmail.com> wrote: It makes one wonder then how hard it would be to rig up a card with a Lance chip (7990) and either IDE or SCSI - I know there are "memory expansion" slots, but don't know how finicky the machine might be about borrowing some of that address space for I/O (or if the slots could decode regions already _in_ I/O space). Abstractly, I know how to do this on M68M machines, but I lack specific knowledge of the innards of the 3B1/7300 to predict how this would go. Of course, the expected market of such a peripheral would be somewhat small, and I suppose if it were easy, there would have been something like it 15 years ago. Still - it's easy to dream one up. Back when they were new, I would have loved to have had one, but they were priced far out of my reach (though many of my local friends who worked at the Columbus Bell Labs/Western Electric plant bought them through employee discounts - we were all part of a county-wide UUCP network in the days before ISPs and dialup PPP links were common. Later, many of the 7300s were gradually replaced by 386s running Interactive UNIX, which I _could_ afford). Was there ever an attempt made at a replacement, or was the nature of the machine (i.e., closed-source controlled by AT&T) such that user-initiated projects were doomed to fail? -ethan