[Coco] CoCo3FPGA, FPGA Development, and GIME replacement

Wed Jul 6 20:10:57 EDT 2011

On 07/06/2011 10:52 AM, Leonard Miller wrote:
> Thank you for clearing up some of my questions.  You even answered questions
> that I didn't even ask yet:-)!  I wasn't so interested in games although I
> do have an interest in adventure type games done up os-9 style.

I'd like to see more of that kind of thing myself.

JCE

> I really
> like the hardware approach for the present&  future.  I also like the idea
> that I can simply upload the file and use the board right away.  I might
> even learn something along the way.
>
> Leonard
>
>
> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On
> Behalf Of Joel Ewy
> Sent: Wednesday, July 06, 2011 11:31 AM
> To: CoCoList for Color Computer Enthusiasts
> Subject: Re: [Coco] CoCo3FPGA, FPGA Development, and GIME replacement
>
> On 07/06/2011 07:36 AM, Leonard Miller wrote:
>> I have been following the discussions about the CoCo3FPGA for some time.
> If
>> I was to purchase a FPGA board which one should I get?  I know that the
> FPGA
>> boards are boards that allow the user to use software to program hardware,
>> but that's about it.  I believe the guys working with this use a couple
>> different boards?  This would be a HUGE endeavor on my part, but it might
> be
>> fun to learn something new as long as I don't get overwhelmed doing it:-)!
>>>  From what I've seen so far; I can use a current computer monitor, but
> what
>> about storage?  Can the board interface to an IDE type drive?  How do I
> move
>> software back and forth between what I currently have (coco3), and the
>> board.  Also, what type of power supply do I need to power the board?
>>
>>
>> Leonard
>>
> The two boards that can presently run CoCo3FPGA are the Digilent Spartan
> 3 (which has a Xilinx FPGA) and the Terasic DE1 (which has an Altera
> FPGA).  Gary's original CoCo3FPGA design was done on the Digilent
> Spartan 3 board, and that's why I got one of those.  He later ported it
> to the DE1, and now supports both, though it seems like the DE1 has
> become more popular among users, and the recent versions have been
> released for the DE1 first.
>
> Each board has its pros and cons.  The Spartan 3 is, I gather, somewhat
> smaller than the DE1.  I have mine installed in an old CoCo 3 case:
> http://8littlebits.wordpress.com/2010/12/18/an-old-case-for-a-new-coco/
> I believe that the Spartan 3 board has more memory than the DE1.  I
> think the Spartan has 2M of SRAM and the DE1 has 512K.  On the other
> hand, the Digilent board needs to be modified in order to display even
> the CoCo 3's 16/64 colors, with further modification required for the
> new 256 color mode and 12-bit palette.  (I think an alternate way of
> displaying the colors uses a small breakout PC board with a VGA
> connector and resistors, so you don't need to actually modify the
> original board.)  The DE1 has full support for both the old and new
> video modes built in.  The DE1 also has an SD card interface, though at
> this time it is not supported in CoCo3FPGA.  I think the price of the
> two boards is comparable -- in the $150 range.  I think the DE1 may also
> have audio circuitry built in.  Both boards require extra interface
> circuitry to interface with CoCo joysticks (and for the Spartan 3 board,
> audio out).  Gary has designed the CoCo peripheral interface boards (I
> think he may not yet have finished the re-designed Spartan board) and
> makes the schematics and PCB layout files available for free, but I
> don't think you can buy manufactured, assembled boards at this point.
>
> I guess if you really want 2M of RAM and don't mind doing a little extra
> work, the Digilent Spartan 3 gives you more memory.
>
> But the DE1 will probably be the easier route if you just want to plug
> it in, upload the bit file, and go.  If you want to hook up CoCo
> joysticks you're going to have to build an interface board in either case.
>
> Both of these boards will come with a little wall-wart to power them.
> The only storage option at the moment is Drivewire, so you'll need a
> modern-ish PC with Linux, MacOS, or even MS-Windows, and Java.  And
> you'll need a serial cable or a serial<->USB adapter.  No IDE at the
> moment, but it should be possible for somebody do design an IDE
> interface for either or both FPGA boards.  If you want to move software
> or data between a 'real' CoCo and CoCo3FPGA, that can be accomplished
> with Drivewire.
>
> One other caveat:  The 6809 implementation in CoCo3FPGA is not cycle
> accurate to a real 6809.  It runs the same instructions, but not always
> in the same number of clock cycles.  This means that some programs
> (mostly games) that rely on careful counts of the clock cycles of
> instructions for timing purposes may not work right.  So you may be
> disappointed if you just want a replacement CoCo to play games.
>
> On the other hand, CoCo3FPGA can run at ~21MHz, has enhanced graphics
> modes, and has the equivalent of an Orchestra 90 stereo sound Pak built
> in.  Furthermore there is potential for future development, and if/when
> Gary releases the source (as he has suggested he will do) development
> won't have to cease when Tandy (or Gary Becker) decides it's not fun
> anymore.  I don't think there will ever be a mass-produced,
> shrink-wrapped Next Generation CoCo.  But if there's enough interest, we
> could very well see hobbyist-produced kits that make it pretty easy to
> plug in one of the FPGA development boards, upload the CoCo3FPGA bit
> file, and go.
>
> JCE
>
>> -----Original Message-----
>> From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com]
> On
>> Behalf Of Rogelio Perea
>> Sent: Wednesday, July 06, 2011 5:40 AM
>> To: CoCoList for Color Computer Enthusiasts
>> Subject: Re: [Coco] CoCo3FPGA, FPGA Development, and GIME replacement
>>
>> On Wed, Jul 6, 2011 at 3:20 AM, Nick Marentes wrote:
>>
>>
>>> There's always a version 2!!   :)
>> I second (or third?) that!.
>>
>> "Design Freeze", a concept that if not followed will keep the R&D in a
> loop
>> never reaching (or reaching late if at all) the goal to have something go
>> from the drawing board into production. Seen that happen all the time,
>> unchecked it can kill an organization.
>>
>>
>> -- RP
>>
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> http://five.pairlist.net/mailman/listinfo/coco
>>
>> __________ Information from ESET Smart Security, version of virus
> signature
>> database 4628 (20091122) __________
>>
>> The message was checked by ESET Smart Security.
>>
>> http://www.eset.com
>>
>>
>>
>>
>>
>> __________ Information from ESET Smart Security, version of virus
> signature
>> database 4628 (20091122) __________
>>
>> The message was checked by ESET Smart Security.
>>
>> http://www.eset.com
>>
>>
>>
>> --
>> 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
>
> __________ Information from ESET Smart Security, version of virus signature
> database 4628 (20091122) __________
>
> The message was checked by ESET Smart Security.
>
> http://www.eset.com
>
>
>
>
>
> __________ Information from ESET Smart Security, version of virus signature
> database 4628 (20091122) __________
>
> The message was checked by ESET Smart Security.
>
> http://www.eset.com
>
>
>
> __________ Information from ESET Smart Security, version of virus signature
> database 4628 (20091122) __________
>
> The message was checked by ESET Smart Security.
>
> http://www.eset.com
>
>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco
>