[Coco] OS-9 graphics using C

[Robert Gault]

Todd Wallace wrote:
> Hey guys,
>
> So I have been continuing to experiment and learn to write simple programs for OS-9 in C.  I have reached the point where I'd like to manipulate the screen, such as background/foreground colors and locating the cursor in specific parts, etc.  The documentation I have checked so far is "Microware C Compiler User’s Guide" which explains about standard input/output, compiling, etc.  I also have been through "The complete Rainbow guide to os-9 level II. volume 1: a beginners guide to windows".  This has taught me how to use the "display, wcreate, iniz" commands etc in OS9 to manipulate the screen.  But I still lack the knowledge of how to perform those commands from C. And finally "The NitrOS-9" level 2 windowing system" which again taught me alot about manipulating windows in os9 but not how to do any of that stuff from C.  I suspect I will somehow need to use the _os9 system call in C, but I have no reference as to the possible commands I can do with that.  Any help is appre
ciated as always! :-)
>
> - Todd Wallace
>

You can probably find built-in calls in the C library but you could always write 
a short asm program and interface it with C. Disassemble the OS-9 command 
'display' to see how graphic commands are sent to the OS-9 system. The same type 
of call can be made from a C program.