[Coco] 6309 microprocessor project 02-02-2004

[John Collyer]

I just finished up the bank switching stuff for
$FF40 - banked switched rom/ram. This
completes the memory stuff. This includes
$FF7F Multi-Pak, NoCan 64MB extension
registers, MMU 2MB registers, and $FF40
bank switched 16K/32K rom/ram.

That make two hurdles gone that would prevent
me from changing the emulator into 32-bit 80x86
assembly source code. The 6309 and the memory
is the backbone of our emulator. There are many
more and some very complex issues to confront
though before it is finished. However there is much
more power built into the emulator with the virtual
FFxxH memory.

Since I'm inside of the $FF40 area I'm beginning here
next and I'm going to virtualized it into the default
Floppy Disk Controller driver. I will only support
the header information exactly like in any other coco 3
version of the emulator. No new header information will
be added to the virtual Floppy Disk Controller driver.

John Collyer

----- Original Message ----- 
From: "John Collyer" <johncollyer at zoominternet.net>
To: "John Collyer" <johncollyer at zoominternet.net>
Sent: Monday, February 02, 2004 11:21 AM
Subject: 6309 microprocessor project 02-02-2004


> 6309 microprocessor project:
>
> Hello,
>
> The virtual FFxxH memory giving you total control over the virtual
hardware
> plugged into the emulator.
> This statement is true, but there are some catches to removing or
replacing
> default FFxxH memory.
> The catch includes the fact the in a real coco 3 many of these addresses
are
> wired to it's memory
> address and many FFxxH memory locations exhibit this behavior including
but
> not limited to the
> MMU registers, PIA 1&2 registers, palette registers, and sam registers to
> name just a few.
>
> Without the functionality of the FFxH memory area acting like the default
> behavior, for the some of these
> memory addresses, these types of overrides for virtual memory addresses
> would mean you no longer
> have a coco 3, but some strange thought up idea of a totally
unrecognizable
> computer system.
>
> If you make the software to use your newly defined computer system great!
> However, if when your
> overriding the default behavior you include the default behavior as well
as
> your new FFxxH memory
> behavior for your virtual hardware and you'll keep the coco 3's default
> functionality along with your
> new functionality.
>
> John Collyer
>
>