[Coco] Chris Hawk's Rapsbery PiCo

[Allen Huffman]

On Mar 30, 2013, at 6:54 PM, Christopher R. Hawks <chawks at dls.net> wrote:

> Allen Huffman <alsplace at pobox.com> wrote:
>> That makes sense. I do not know enough about the architecture of MESS
>> to know how easy it would be to create a new input device for it,
>> assuming it even knows about anything other than USB or PS/2 style
>> devices.
> 
> 	I'm not quite sure how to explain, but, I'll try. Mess doesn't
> know anything about USB or PS/2. It simply receives input events from
> the OS (Linux, OSX, or Winder$ or whatever) and uses the 'device
> emulators' code (CoCo in our case) to generate signals that are
> expected. In the CoCo's case, when the 'CoCo' scans the keyboard 'PIA',
> the emulator clears or sets the proper 'PIA' bits so that the
> 'CoCo' sees that a key in the matrix was pressed (the key with the
> value of the key that generated the keyboard event). So you'd have
> to write a system driver to use the Raspberry Pi's I/O.

Ah, that fully explains it. Having a Teensy spit out USB HID data (which the computers already handle) was a much easier way to do it. Gotcha. I was hoping perhaps MESS had modular system input routines and one could just be hacked to look for the pins. But, then the code would have to actively poll for changes, adding overhead.

>> What led you to choose that particular version of MESS? I see, on
> 
> 	Lots of 'stuff' has been added to the later versions. I don't
> even use the latest #%*($^ on my regular computer as the 'MIDI' stuff
> is so wrapped up I couldn't make it compile without it, even tho none
> of the remaining emulated boxes (CoCos, Dragons, and clones) use it.
> (And I had all ready stripped down v0.125 for use on my regular
> computer.)

Understood. I look forward to more tutorials from you :-)

-
Allen Huffman - PO Box 22031 - Clive IA 50325 - 515-999-0227 (vmail/TXT only)
Sent from my MacBook.

22nd Annual "Last" Chicago CoCoFEST! April 27-28, 2013. Lombard, IL. http://www.glensideccc.com - And check out the CoCo-X project: http://kck.st/16fAwkf