[Coco] Where can I find information on using the Cartridge port for I/O ?

[tim lindner]

On Thu, Dec 24, 2020 at 10:53 AM Neil Cherry <ncherry at linuxha.com> wrote:
>
> I'll start out simple as I'm sure there's a lot I don't know.
>
> I want to build a cartridge with an interface to a USB keyboard using the CH376. What information
> is available for using the Cartridge port for I/O with ROM on the board. I'll need the board to
> be read at startup so that it can add the interrupt chain.

I'll leave it to others to talk about the hardware. But for linking in
your software additions is a little tricky.

Extended Color BASIC will look for a 'DK' at $C000 and jump to $C002
to let your code initialize. But everyone will already have a disk
controller that has it's own ROM and will be executed first.

Unfortunately, Disk BASIC is not programmed to search the MPI slots
for other ROMs.

The first option I can think of is to have your customers LOADM in a
TSR that applies the patches you need.


-- 
--
tim lindner

"Proper User Policy apparently means Simon Says."