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Path: utzoo!mnetor!seismo!rochester!dibble
From: dibble@rochester.ARPA (Peter C. Dibble)
Newsgroups: comp.sys.amiga,comp.sys.atari.st,comp.sys.m6809
Subject: Re: True Multitasking, and some history lessons
Message-ID: <28419@rochester.ARPA>
Date: Thu, 11-Jun-87 15:56:45 EDT
Article-I.D.: rocheste.28419
Posted: Thu Jun 11 15:56:45 1987
Date-Received: Sat, 20-Jun-87 11:41:03 EDT
References: <8706040024.AA10895@cogsci.berkeley.edu> <2194@husc6.UUCP> <1735@ihwpt.ATT.COM>
Organization: U of Rochester, CS Dept., Rochester, NY
Lines: 28
Summary: Shared libraries in OS-9/68K
Xref: mnetor comp.sys.amiga:5706 comp.sys.atari.st:4000 comp.sys.m6809:345

In article <1735@ihwpt.ATT.COM>, knudsen@ihwpt.ATT.COM (mike knudsen) writes:
> In article <178@dana.UUCP>, rap@dana.UUCP (Rob Peck) writes:
> > Library of stdio ... good idea, anyone want to tackle it?
> > Rob Peck	...hplabs!dana!rap
> 
> I'm just a "lowly" Coco-3 (6809) hacker, but I seem to recall
> that OS/K (68000 OS9) does indeed share the whole stinkin'
> StdIO library, so when you have a half dozen C programs loaded,

OS-9/68K supports "trap handlers."  Two of them come with the system:
a stdio trap handler and a floating point trap handler.  The program
does some fussing around to "install" the handler, then it uses
a trap to access the routines in the handler.  You need a trap per
trap handler, so there is a limit on the number of separate libraries
a program can use without swapping trap numbers around.

The technical manual describes the protocol for the floating point
handler.  The stdio handler is undocumented, and it looks a bit
tricky to call.

(Nice thing about the floating point handler:  if you have
a 68881 you just install the handler that uses it.  Programs
start using the coprocessor without any changes.)

On the 6809 subroutine modules could be used to achieve almost
the same effect.

Peter Dibble