[Coco] Raspberry Pi and RS-232 ports

[Andrew]

In theory it could be done; the quickest way would be to (somehow) get a 
CoCo emulator written in standard C/C++ and cross-compile to the ARM 
core used in the Pi. At least - that's the high-level view. There's a 
lot of low-level stuff that -would- make this a herculean effort (video 
being the main one).

It's been a while since I last looked at CoCo 3 emulators - I seem to 
recall that David Keil released the source to his CoCo 3 emulator, but I 
can't seem to find it (I know I have a copy myself - but I can't seem to 
find it on the web). But I did find the VCC source (for Windows) - and 
it's in C. So maybe that could be futzed with to get it into something 
more portable and standard? Probably the first step would be to get it 
to run under Linux using the framebuffer. Then port that?

Another possibility would be to take the whole MESS version, and strip 
it down to the bare-bones to get it to run the CoCo 3 - then port that 
code (I'm pretty sure MESS is written in C or C++). Again, you'd want to 
target the framebuffer, of course.

Lastly - and this is something that could be tried with MESS, because 
I've seen some tutorial on the technique - you could try to boot a 
bare-minimum X window system, that immediately starts MESS. Strip the 
linux kernel down to the bones, kick off X, then MESS (with CoCo 3 
roms). While it won't be "instant on", it will probably be a lot better 
than "standard" linux bootup on the Pi. Something like this:

https://blogs.wcode.org/2013/09/howto-boot-your-raspberry-pi-into-a-fullscreen-browser-kiosk/

Keywords to grep are "browser kiosk fullscreen" - the takeaway is that 
you don't need a full-on desktop to run an X window aware piece of software.

Ooh - another interesting possibility:

https://devtidbits.com/2013/04/23/run-dos-on-the-raspberry-pi-use-rpix86-to-turn-your-pi-into-a-1980s-super-computer/

http://rpix86.patrickaalto.com/

...then run one the DOS CoCo 3 emulators on top of that, perhaps?

-- Andrew L. Ayers, Glendale, Arizona

> Message: 3
> Date: Fri, 31 Mar 2017 13:15:36 -0500
> From: Dave Philipsen <dave at davebiz.com>
> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> Subject: Re: [Coco] Raspberry Pi and RS-232 ports
> Message-ID: <7fa405aa-019f-85e8-def1-d1824713c955 at davebiz.com>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> I think, actually, that someone has already emulated a CoCo on a
> Raspberry Pi.  I've seen it mentioned here and there.  But someone
> pointed out some days ago that a Raspberry Pi takes a finite amount of
> time to boot and there's nothing like a good ol' CoCo that starts up
> pretty much immediately.  I brought up the idea that if a Rasperry Pi
> was only going to emulate a CoCo and nothing else it could surely be
> made to boot up instantly just like a CoCo.  After all, it has a CPU
> that runs at a clock speed of several hundred megahertz!  But I was
> speaking only theoretically.  I imagine it would be a herculean software
> effort to get in to the internals of the Pi and figure out how to get it
> to boot up and run as a CoCo without the aid of the Linux (or other)
> operating system.  It's certainly possible but it doesn't seem like it
> would be worth the effort just to save the 15 seconds or so required to
> boot into Linux and then run a CoCo emulator.
>
> Dave