[Coco] Raspberry Pi and RS-232 ports

Glen Hewlett glen.hewlett at sympatico.ca
Sun Apr 2 17:28:11 EDT 2017


Hi Ron,

It sure is sounded great already.  I’m looking forward to using your RPI3 image too.  No hurry, I just wanted to let you know I appreciate all your effort.

Cheers,
Glen

> On Apr 1, 2017, at 12:30 PM, Ron Klein <ron at kdomain.org> wrote:
> 
> Hi Andrew,
> 
> I've been working on getting an initial Raspberry Pi 3 Coco emulator
> distribution set up for those who might be interested to try for
> themselves.  It's being set up the why I like it, but could certainly be
> taken in any direction from the community as I plan to share an SD image
> soon.
> 
> This is what I have so far:
> 
> Raspberry Pi 3
> 
> Latest Raspbian distribution
> 
> Some RPi3 performance tweaks to allocate memory for programs and video.
> 
> Restrict video mode to 640 x 480 (rather than the 1920 x 1080).
> 
> A very slight CPU over clock and force all cores to be active all the time.
> 
> Latest MAME (0.184) compiled with SDL2 (and video hardware acceleration).
> It runs from the console, no X involved.  I'm working on just compiling a
> version to support only the Coco / Dragon targets, but not a priority just
> yet.  For those interested, ChoccyHobNob provides precompiled, current
> versions of MAME for the RPi3:
> 
> http://choccyhobnob.com/mame-0-184-for-raspberry-pi-macos/
> 
> ... great site and information.
> 
> Latest XRoar for those who prefer that emulator for Coco 2 / Dragon
> emulation.  It can be run from console or X, though the X version is very
> nice with the added benefit of menus, etc..
> 
> Drivewire 4 configured to host/serve DSK images to the local instance of
> MAME (or XRoar) running on the RPi3.  If you use a USB to serial adapter or
> one of the serial interfaces to connect to the GPIO header, you can host
> files for a real Coco as well.
> 
> Some scripts to start a Coco 2, Coco 3, MC-10 from MAME.  For the Coco 3, I
> have it configured with 2MB of RAM.  Great for NitrOS9 and Fuzix.  Any of
> these could be added to the /etc/rc.local file to boot directly into.
> 
> I've also added am EMCEE server to host files for a real MC-10.
> 
> Samba server and client packages.  You can transfer and DSK images, roms,
> etc., to the RPi3 from another workstation on your network or you can
> connect to other file server on your network from the RPi3.  Either way
> works and is available.
> 
> Added a bunch of Coco development tools the distribution including
> everything needed to compile MAME and XRoar, lwtools, Toolshed, etc..
> 
> Added William Astle's excellent lwwire application (with modifications from
> Brett) to allow Fuzix (running on a Coco 3) access to the Internet.  This
> can include an emulator running on the RPi3 or a real Coco 3 connected to
> the RPi3 through the USB or GPIO serial port.
> 
> I connect my RPi3 to a LCD monitor that happens to have both a HDMI and VGA
> connections.  I have not tested the RPi3's composite video output on the
> GPIO header, but will get to that at some point.
> 
> I use a basic USB mouse and keyboard.  I came across a great deal on a
> Nintendo Wii U Pro Controller which works perfectly with the RPi3 as it
> already has built-in Bluetooth support.  Raspbian recognized the device
> with no issues.  I was playing Pop Star Pilot just yesterday using it.
> Very nice.  Nice thing is that controller has analog and digital control
> support.  Perfect the Coco!
> 
> I know there's been much talk about booting into a Coco instantly at
> power-up.  I have not attempted to do that, but the boot process is very
> quick now (under 15 seconds).  I'm OK with that, but I'm sure there may be
> other things to do to improve it more.  Unless you create an emulator that
> doesn't require the Linux OS and talks directly to the hardware, not sure
> if there will ever be a way to achieve instant-on access to a Coco.
> 
> The last part of my RPi3 testing is connecting a real Coco 3 keyboard to
> the RPi3.  I'm using information provided by Chris Hawks who really
> pioneered the early Coco emulation for the RPi.  I have the extra keyboard
> and Coco 3 case, so I may be able to build my own CocoPi, just like Chris
> did a while back.  With things like the USB to Coco joystick adapters, it
> might even be possible to use real Coco joysticks with the RPi while it's
> in a Coco case (using the factory holes on the case).  The RPi3 composite
> video and analog audio port could be run to the factory location on the
> case, too.  These types of things would require some sort of basic
> backplane to mount the 6 pin joystick DIN connectors and the composite
> video and audio connectors.
> 
> Anyway, getting a bit closer each day.  I would like to share something
> soon, but need to find a way to limit the size the SD card image and find a
> place to host it.
> 
> Thanks!
> 
> -Ron
> 
> 
> 
> On Sat, Apr 1, 2017 at 2:08 AM, Andrew <keeper63 at cox.net> wrote:
> 
>> 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
>>> 
>> 
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> 
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