matt@prism.UUCP (10/22/85)
/* Written 2:16 pm Oct 17, 1985 by caf@omen in prism:net.micro.pc */ > In article <1040@mtuxo.UUCP> attpc@mtuxo.UUCP (AT&T PC 6300 PLUS) writes: > >OS Concurrency "OS Merge" allows MS-DOS to run > > concurrently with UNIX System V. > Since this is a technical newsgroup, let's see some discussion about how > the "OS merge" is implemented! If I'm not mistaken (and I may be), OS-Merge was developed for AT&T by Locus, the California group that has also worked on a distributed Unix system and a "bridge" between MS-DOS machines and Unix machines. The bridge software looked interesting when I inquired about it a few months ago. It runs on top of and Ethernet and allows each machine to see another machine's file system as a hierarchical directory structure in a format it can recognize. The PC end runs code that intercepts all the "appropriate" DOS (and BIOS?) services to manipulate the filesystem and decides whether they're supposed to operate on the local disks or on a remote "virtual" directory. In the latter case, the requests are forwarded on to a daemon running on the remote machine. File formats are fixed up on the fly, so an application cannot tell the difference between a file on a local (DOS) disk and a file on a remote (Unix) disk. All in all, it looked like things were done the right way. If the Unix end had been available on a Pyramid, we might have bought it at the time. Locus is on the net (ucla-cs!locus!... ??), so I'm sure someone there can correct any misstatements I've made. ------------------------------------------------------------------------------- Matt Landau ARPA: matt%mirror@cca Mirror Systems, Inc. UUCP: {decvax!cca, ima!inmet, mit-eddie, wjh12}... Cambridge, MA ...mirror!matt ------------------------------------------------------------------------------- Blessed are they that run around in circles, for they shall be known as wheels.