[Coco] [COCO] Raspberry PI and CoCo Cart

[David Ladd]

Here are one of the chips I was looking at.
http://www.jameco.com/Jameco/Products/ProdDS/392446.pdf

It has both a in and out clock so shouldn't be a problem timing data
between Pi and CoCo.  Just need the cart with two chips that are like
this and should be able to put together something that will interface
the two together.

I am still going through the chip list.  I will post when I find
something that is a bit better.

On Fri, Oct 5, 2012 at 7:48 PM, Aaron Wolfe <aawolfe at gmail.com> wrote:
> On Fri, Oct 5, 2012 at 7:54 PM, David Ladd <drencor at gamepixel.net> wrote:
>> Well my idea is is just addressing two FIFI buffer's at the Boisy
>> Interface/Becker ports and then maybe modify the Drivewire 4 server to
>> talk via parallel rather than serial using the Raspberry Pi's
>> interface.  I need to find a parallel FIFO chips that can do this.  I
>> figured a parallel interface would be a bit faster than serial plus
>> two FIFO chips would provide at least a good buffer to allow the CoCo
>> to catch up under OS-9 if other processes are going on between
>> packets.
>>
>> Though I don't have a Pi yet and I figured since you have a Pi and
>> wrote DW4 server that could come up with the required hardware to
>> combine the Pi into a cart to basically be the CoCo's version of the
>> Boisy Interface/Becker port.
>>
>
> Well.. I haven't the slightest clue about hardware but I have been
> talking to those that do.
> I've gotten the impression a FIFO/Boisy/Becker interface is very
> possible for someone
> with the knowledge to make things.  That would be cool, I just wonder
> if we couldn't do
> something a bit lower level and turn the Pi into a flexible I/O
> controller rather than a
> drivewire server on the end of a serial connection... there are some
> pretty massively
> nice things such a device could do.
>
>> The only thing I know right now is that anyone who still uses a J&M
>> Controller with a built in parallel port would have to switch to
>> another floppy controller since it uses the same address ports.
>>
>> I still need to do more research into the FIFO chips and if 8bit ones
>> are made.
>>
>> I figured using the becker port would make things a bit easier since
>> NitrOS-9 already has the DW driver for it.  The only thing that would
>> need to be done is for someone who has rights to update the source
>> code to the HDBDOS project could update the DW read and write files to
>> include the becker port and then add to the make file to produce
>> another HDBDOS image that includes a becker compile of HDBDOS.
>>
>
> It's true that implementing the B/B interface means no additional software needs
> to be written..  conversely it also means no additional functionality,
> just much
> better speed.  That's good, but I want to at least explore doing more.  It may
> well end up that a fifo is the only practical way but I haven't given up yet.
> If we had a way to communicate from coco to usb/ethernet/etc on the pi,
> believe me I will write the software to use it.
>
>
>> On Fri, Oct 5, 2012 at 6:24 PM, Aaron Wolfe <aawolfe at gmail.com> wrote:
>>> I have been wanting/planning/trying to gather information on a "Pi in
>>> a Pak" for some time now.
>>>
>>> Interfacing via a faster, less CPU intensive DriveWire connection is
>>> interesting, and maybe that is the limit of what can be done.
>>> However, I had hoped for something a bit different.  I've talked with
>>> some experts (or at least they know a heck of
>>> a lot more about it than I do) and gotten some ideas but maybe the
>>> list has some too...
>>>
>>> It seems like the ideal (and maybe unobtainable) interface would be
>>> one which can read and write directly to the
>>> bus lines just like a regular ROM pak or drive controller.  Given this
>>> ability, one could accurately simulate *any*
>>> pak or peripheral (or several at a time?).  You could also create new
>>> peripherals, such as interfaces to the various
>>> I/O found on the Pi (USB, ethernet, audio/video, etc...).   Way better
>>> than an embedded DW server imho.
>>>
>>> I don't know if its possible or practical, I just know that it would
>>> be awesome.  From what I've gathered... it might be possible
>>> but it's not a sure thing.  You have to dance pretty fast to play on
>>> the bus.  The Pi does have an SPI interface capable of many
>>> Mb/s throughput (one guy's testing says 16Mbps is a practical limit)
>>> in addition to several GPIO pins.  John Kent showed me
>>> a cheap I/O processing chip that was cheap, programmable, had SPI and
>>> a whole bunch of latches, and could operate in the
>>> multi Mhz range.  Can they be stuck together into something that can
>>> participate on the coco bus?  I wouldn't even know how
>>> to guess, but I'd surely like to find out.  Also interested in
>>> alternate schemes that provide superior/more direct communication
>>> than the DW style serial line.
>>>
>>> Can the Pi be turned into the ultimate virtual MPI?  $0.01 for your thoughts
>>>
>>>
>>>
>>>
>>> On Fri, Oct 5, 2012 at 7:09 PM, David Ladd <drencor at gamepixel.net> wrote:
>>>> One of the things I was thinking is with the cart side is having two
>>>> FIFO chips to buffer data between the Raspberry Pi and the CoCo.
>>>>
>>>>
>>>> On Sat, Sep 29, 2012 at 5:58 PM, Aaron Wolfe <aawolfe at gmail.com> wrote:
>>>>> On Fri, Sep 28, 2012 at 10:42 AM, Brian <briang0671 at sbcglobal.net> wrote:
>>>>>> On 09/28/2012 12:05 AM, David Ladd wrote:
>>>>>>>
>>>>>>> Here is a interesting idea I just had.
>>>>>>>
>>>>>>> What if we were to interface a Raspberry PI and have it connected to a
>>>>>>> CoCo cart so you could take advantage of the Boisy Interface/Becker
>>>>>>> port so that you could have faster access to drivewire 4 server?
>>>>>>>
>>>>>>
>>>>>> What is the Boisy Interface/Becker port?
>>>>>>
>>>>>
>>>>> This is a fifo buffer interface implemented initially in the CoCo3FPGA
>>>>> project and since ported to some emulators.  It allows DW to operate
>>>>> at very high speed/low cpu use compared to bitbanger on those
>>>>> platforms.  OS9 modules to support the interface are in the NitrOS9
>>>>> source.
>>>>>
>>>>> --
>>>>> Coco mailing list
>>>>> Coco at maltedmedia.com
>>>>> http://five.pairlist.net/mailman/listinfo/coco
>>>>
>>>> --
>>>> Coco mailing list
>>>> Coco at maltedmedia.com
>>>> http://five.pairlist.net/mailman/listinfo/coco
>>>
>>> --
>>> Coco mailing list
>>> Coco at maltedmedia.com
>>> http://five.pairlist.net/mailman/listinfo/coco
>>
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> http://five.pairlist.net/mailman/listinfo/coco
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco