[Coco] CoCoUSB

[RETRO Innovations]

On 4/20/2018 9:58 AM, Allen Huffman wrote:
> Is there any interest in a CoCoUSB interface?
I've had interest for a long time, but have resisted it because there 
are lots of people who will assume that a USB port will accept any USB 
device and will publicly lament the inability to do so if the device 
seems "close enough" to a device the unit was designed to support.
>
> It would be easy to add support to iItrOS-9, but RS-DOS would require patching (and as we know, any time you patch BASIC, you break things, since many programs go out and read hardware directly rather than using ROM calls). Think of it like the hard drive BASICs — you can make simple basic disk I/O work, but much assembly stuff wouldn’t work with it.
I think a better solution is to make the USB device act like their 
native counterparts.

  * USB KB, emulate the native KB capability
  * USB Mouse: emulate the native joystick capability
  * USB Printer: Expose as native serial port connection
  * USB serial device: RS232
  * etc.

>
> However, dedicated “USB joystick to CoC joystick port” and “USB keyboard to CoCo keyboard connector” boards could be done to embed inside the CoCo, which would be 100% compatible.
The problem is that your Coco starts to look like a mess with all of the 
little boards connected everywhere, and it may require socketing some 
ICs in order to use certain adapters.

However, I *think* there is a way to support the USB solutions without 
needing to physically connect to the devices in question (mouse, KB, 
etc.).  I have the beginnings of a design, but need more time to prove 
it out.

Jim