[Coco] memory expansion, SPI interface with VGA output

[Henri Mainville]

Sounds like a lot to ask for, and who has it all ? I think Tormod's MOOH 
<http://tormod.me/mooh.html> might have provided enough functionality to 
make it possible.

Thanks to the work of Tormod, CoCo/Dragon users can get a memory 
expansion board with an SPI and MicroSD interface which helps greatly if 
you want expanded functionality and ease of development on the CoCo/Dragon.

In the mean time, there's a project I've been keeping my eye on which 
has been the VGATonic 
<https://hackaday.io/project/6309-vga-graphics-over-spi-and-serial-vgatonic>, 
serial VGA graphics module which is targeted towards microcontrollers 
and embedded devices with exposed SPI or TTL interfaces and capable of 
driving a display at 640x480 
<https://hackaday.io/project/6309-vga-graphics-over-spi-and-serial-vgatonic/log/20001-hardware-accelerated-lower-resolutions-working>depending 
on your serial speed.

I think these two modules might make the perfect combo for modernizing 
6809-based computers like CoCO/Dragon but it might need a bit of dev 
work on drivers for NitrOS-9 or FUZIX to detect the SPI interface and 
drive the video module connected to it.

I don't know for sure if it's even feasible but I would think so and I 
also wanted to share incase anyone else was curious.


Have a nice day and happy hacking!


Sincerely,

Henri Mainville