[Coco] Virtual Memory in OS-9

[William Schaub]

Bob Devries wrote:
> William said:
>> I just wanted to ask if the operating system has calls for allocating 
>> more memory to a process, or if everything has to have memory 
>> allocated statically.
>
> There are system calls to allocate more memory in OS-9.
> The OS-9 system manuals (level 2) are available in PDF form online. 
> Try ftp.clubltdstudios.com/coco/downunder/OS9/
>
Are there any surviving level 1 docs someplace?
>> Also I really want to know if it's possible to execute programs that 
>> use more memory than is physically installed by paging to mass 
>> storage of some sort.
>> It would be very nice if something similar to the UNIX mmap() system 
>> call is available.
>
> This would require extensive changes/additions to the stock OS-9. Even 
> Nitros9 would need much change. Not saying it isn't possible, but...
>
I'm mainly interested in NitrOS9 I'm looking through the sourceforge 
trees and wondering
what tools are needed to compile it as I might be interested in 
monkeying around with the internals a bit. From looking at the docs 
there appears to be a way to map blocks of memory outside the process 
address space into the process address space. I wonder if a system could 
be setup where theres a paging file  and gets paged into and out of a 
buffer that can be mapped into a processes address space. Only problem 
with that is I'm not sure if there is any way possible to produce page 
faults to drive the pager I think a VM system like I'm used to requires 
a bit more hardware than the coco has availabe.

>> I plan on starting out with the OS-9 C compiler as it looks like it 
>> has a lot of UNIX compat stuff in it. I would like to see just how 
>> much of a UNIX like environment I could re-create on OS-9
>
> The European OS9 usergroup once produces a work called TOP -- The OS9 
> Project. While this was, I believe based around OS9/68000, it was 
> designed to give a UNIX-ish feel to OS9.
>
>> I saw a lot of unix tool ports on the rtsi archive so it cant be too 
>> bad. But I'm wondering if theres a way to make curses apps run on 
>> OS-9 does the OS-9 console emulate any particular type of terminal? 
>> (one that implements escapes for character attributes, cursor 
>> movement and such) at the worst I could always hang a real terminal 
>> off of an RS232 port.
>
> There is a curses port for OS-9/6809, but I've had mixed reports as to 
> whether it works or not. The codes used by OS-9 for screen/keyboard 
> are documented in the manuals.
>
I'm guessing that the same codes work between level 1 and 2. I hope the 
curses port is still around someplace.