[Coco] 64k memory limit (was) CP/M emulator for OS9/6809

Wayne Campbell asa.rand at gmail.com
Tue Apr 29 14:08:02 EDT 2014

On Sun, Apr 27, 2014 at 5:33 PM, Bill Pierce <ooogalapasooo at aol.com> wrote:

> This is not quite so. You can go beyound 64k very easily with common
> "legal" OS9 system calls. Though it doesn't extend the 64k workspace for
> the actual "program size", You can move all buffers and data storage out of
> the of the 64k and into "virtual memory". Also, by calling "fragged
> subroutines", you can extend program length to "unlimited" with limitations
> only by your Coco's physical memory. And it's all done without "cheating".

I have been thinking about this for a long time. I do not know what calls
have to be made, or what is necessary to use more than 64K for a program.
unpack could benefit from this. I could make the disk file reside in memory
as an array of that type, and do many other things without having to use
all those files. Would you share an example of the code that you use do to
make use of this method?

> I do need a "beta" tester or two...
> System requirements are:
> Coco 3 512k (or better) OR Vcc 1.4.3b
> NitrOS-9 w/CoWin or CoGrf, Pipes, DW4 drivers w/ "/Xx" and "/Nx"
> descriptors (standard in the NOS9 distribution disks)
> An OS9 hard drive system (real or virtual). It may run from floppy, but
> really isn't practical. If so, 2 drives would be best.
> DriveWire4 is not actually required, but it is preferred. It "should" run
> without DriveWire though I haven't tested this. The program checks for DW4
> on startup and disables DW features if not found.
> Any "takers"?

 I am using VCC 1.4.3b, but have not yet setup the latest NitrOS-9 build.
Give me time to get the decode documentation written, and I will be able to
concentrate on finally getting this system setup right. I intend to get the
1.5.2 version of MESS with the Becker port, and I will have both emulators
able to connect through DriveWire 4. Sorry it has taken me so long to get
to this point, but I wanted a stable version before I started changing
things around, and the new 3.3.0 release sounds like the ticket to me.

Thanks, Bill.


The Structure of I-Code


More information about the Coco mailing list