Xref: utzoo comp.sources.d:3296 comp.windows.misc:1063
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!bellcore!wind!sau
From: sau@wind.bellcore.com (Stephen A Uhler)
Newsgroups: comp.sources.d,comp.windows.misc
Subject: Re: Does MGR run on other systems besides Suns?
Keywords: MGR windows
Message-ID: <13959@bellcore.bellcore.com>
Date: 10 Feb 89 15:37:57 GMT
References: <213@insyte.UUCP>
Sender: news@bellcore.bellcore.com
Reply-To: sau@wind.UUCP (Stephen A Uhler)
Organization: Bellcore, Morristown, NJ
Lines: 43

In article <213@insyte.UUCP> m2@insyte.UUCP (Mike Arena) writes:
>
>I just got MGR off of comp.sources.unix and I've only seen mention of of
>this working on Suns.  Does this run on other machines (like Apollos)?
>Has anyone tried to port it to other machines?

One of the original reasons I wrote MGR was to reduce our dependence on SUNS,
so some care was taken to make MGR portable, and not Sun specific.  However,
since I still have one, SUN's are still MGR's primary development platform.

I ported MGR to a home-made SYSTEM-V look alike in about a day, and a summer
student ported MGR to a MAC+ (running MAC-OS) in about a week.  In both cases
MGR was restructured to further isolate any system dependencies, hopefully
making the next port easier. Here are some pointers to get you started:

1) Hardware requirements
   - MGR assumes that data may be copied between the frame buffer
    (display memory) and main memory efficiently.  If your machine
    can't do this, you might be in for trouble.  Last I looked, MGR spent
    > 90% of its time updating, saving and restoring parts of the display.
    MGR's performance is directly proportional to the BitBlt speed of
    your machine.
   - MGR uses a 3-botton mouse.  If you don't have one you have to fake it.

2) Porting procedure
   - Write the routines to do BitBlits (i.e. blitlib.a).  If you have a 68020
     you can adapt the stuff in src/blit; if your computer provides BitBlt
     routines (it should), look at the stuff in src/pixrect for a model.
   - rewrite mouse_get(), the MGR mouse interface routine, or
     get a Mouse System's (or compatable) mouse, and plug it into the
     serial port, just to get going.
   - If you have 4.2ish Unix, turn off the sun specific KBD, and BELL compile
     options and you're about done.
	- If you have a SYSTEM-Vish Unix, you need to a) redo the terminal i/o stuff
     in set_mode.c, b) change getshell.c to use the local pseudo-tty and
     process group conventions and c) if you have select() fix mgr.c to use
     select properly or (yuk! no select) just poll all of the file descriptors
     in non-blocking mode, and use a 10th second read timeout on the keyboard
     (stdin) to keep from hogging all of the CPU. (I have a list of changes
     I made for my SYS_V port I can give you).
   - If you have a NON-UNIX machine, it still isn't too bad if you have
     a reasonable display, a mouse, can read and write files, and can deal
     with multiple file descriptors.