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From: blarson@castor.usc.edu (Bob Larson)
Newsgroups: comp.sys.m6809
Subject: Re: os9 level II full screen editor
Message-ID: <2236@castor.usc.edu>
Date: Sun, 17-May-87 21:11:13 EDT
Article-I.D.: castor.2236
Posted: Sun May 17 21:11:13 1987
Date-Received: Mon, 18-May-87 03:51:26 EDT
References: <20@abvax.abnet.com> <58400005@gorgo.UUCP> <1799@lsuc.UUCP>
Reply-To: blarson@castor.usc.edu.UUCP (Bob Larson)
Organization: USC AIS, Los Angeles
Lines: 46

In article <1799@lsuc.UUCP> jimomura@lsuc.UUCP (Jim Omura) writes:
>     Whaaaaat?  Where the heck did you get a silly set of ideas like
>this?  The point of OS-9 is that the majority of code properly written
>following the OS-9 conventions are directly usable under both OS-9
>Level I or Level II.  This is possible because addressing within the
>program is all relative and addressing of data is all base register
>relative.  Level II presumes a hardware Dynamic Address Translation
>which maps the final address to hardware address beyond the 64K limit
>of the 6809 processor.  Under *neither* system would you assume that
>the entire 64K of addressing is available to the program space.  Further,
>you can assume that you'll have more dataspace in a Level II system
>because the program space will not be conflicting with the dataspace.
>Practically speaking you can also assume greater program space as well
>for the same reason.

Correction: os9 does not use separate address spaces for program and
data.  Under the best conditions, an Os9/6809 Level II program will
have 64k total for both program and data.  (Each will be rounded up to
your memory alocation size (coco III 8kbyte, others 2 or 4 kB))

>     As a point of interest, does anybody know what version of MicrEMACS
>the Users' Group has in their library?  Is it still the Conway/Lawrence/Santy/
>Larson port or is it the new MicroGNU, or something else entirely?

As far as I know it is.  I do plan on sending mg 1b in, but it won't
replace the 6809 portion of the old microemacs.

>Has anybody tried the MicroGNU on a 6809 machine yet?

I assume you mean MicroGnuEmacs (mg).  (GNU is an operating system,
not an editor)  Porting to a 64k machine would involve stripping out a
lot of features.  My preliminary work on mg 2 is making in better,
smaller, frequently faster, and with more things conditionally
compilable, but there are limits.  I'm not going to spend time
figuring out how to rip the guts out of mg, besides after you rip out
most features it might be hard to tell microemacs versions apart.  It
might be better to start with something that doesn't require the whole
file to be in memory for a 6809 editor.

I should get around to ordiering my QT20x, 1/2 megabyte on my QT+ just
isn't enough for a good editing session.
-- 
Bob Larson
Arpa: Blarson@Usc-Ecl.Arpa
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