holtz@zurich.csmil.umich.edu (Brian Holtz) (10/21/89)
In article <650@studsys.mu.edu> stevej@studsys.mu.edu (jovanovic) writes: > >Also, how stable is it, and what kind of toolbox support does it >provide? Can it be run under Multifinder, so that Mac OS app's >can be run in the background? Specifically, I'd like to know if Mac OS applications can run under A/UX in a networked window system like X, so that, say, I could fire up Excel on my Mac but have it accept input and show output on another workstation's display. I've heard that there's an X server that runs under Mac OS; would this be a way to have regular Mac applications display remotely on other workstations? Is there _any_ way to do such a thing?
klee@chico.pa.dec.com (Ken Lee) (10/21/89)
In article <1989Oct20.183825.6061@csmil.umich.edu>, holtz@zurich.csmil.umich.edu (Brian Holtz) writes: > I've heard that there's an X server that runs under Mac OS; would this > be a way to have regular Mac applications display remotely on other > workstations? Is there _any_ way to do such a thing? I'm pretty sure the answers to your questions are no and no, at least with currently available software. The Mac X server only supports X clients running on other machines and connected via Ethernet (or possibly other networks). You could theoretically write a version of the Mac toolkit that converted the toolkit interface into X protocol, but I know of knowone working on anything like this. Mac OS and the Mac toolkit have many nice features. Networking of applications is not one of them. Ken Lee DEC Western Software Laboratory, Palo Alto, Calif. Internet: klee@decwrl.dec.com uucp: uunet!decwrl!klee
barmar@kulla (Barry Margolin) (10/21/89)
In article <1989Oct20.183825.6061@csmil.umich.edu> holtz@zurich.csmil.umich.edu (Brian Holtz) writes: >I've heard that there's an X server that runs under Mac OS; would this >be a way to have regular Mac applications display remotely on other >workstations? Is there _any_ way to do such a thing? No. An X server allows applications on other machines to display in windows on the server machine. In order to allow ordinary Mac applications to display remotely, the low-level managers and toolboxes that access the screen directly would have to be reimplemented using X operations. This is a large, difficult conversion, often requiring some redesign of the display manager because of changes in underlying assumptions. Symbolics spent a couple of years doing this to their Lisp Machine window system so that it would work in the MacIvory and UX400S co-processor environments. Console drivers written for hardwired displays generally assume that they can access the console atomically, and that reading/writing bitmaps from/to the display is a cheap operation, and applications often make similar assumptions. This is not the case when the display is at the other end of a network connection. Routines that normally run at interrupt level now must make calls to network stream interfaces, and handle all the myriad exceptional cases that may be involved. Consider the way screen fonts are handled. The Mac keeps lots of bitmaps around, and simply copies them to the screen; in System 7.0 it will keep outlines around, compute bitmaps as needed, and copy them to the screen. In X, however, the performant way to display characters is to send character data to the server, allowing it to look up bitmaps from its own fonts. This means that the available fonts depend on the server you're using; you may get strange results if you write a file directly on a Mac, and then look at it again while using an X server on a Sun. Symbolics's decision was to make both styles of text output available, at the choice of the application that creates a window. They also provide a way to convert Symbolics font files into X font files. Barry Margolin, Thinking Machines Corp. barmar@think.com {uunet,harvard}!think!barmar