[Coco] An FPGA GIME project, and CoCo FPGA Experimenter's Board

[Bill Nobel]

Come to think of it Ed, just a random thought I have.  How about a register that will control a page of hardware instead of ram or rom.  In other words the range of $FF00 to $FFxx be paged for different hardware (not the rom vectors or core of RSDOS or Nitros9/OS9 under mode Coco3) Say 8 pages selectable in the same range. I have thought of this before but under normal hardware wiring it wasn’t possible.  But now the idea of replacing the GIME with a FPGA, opens lots of doors….

Bill Nobel

> On Oct 21, 2015, at 9:29 PM, Bill Nobel <b_nobel at hotmail.com> wrote:
> 
> Yes, it is just a register somewhere in memory that will trigger a more enhanced set of hardware layers that can do much more.  Gary Becker has already shown this on his Coco3FPGA by adding more colours and Graphics modes.
> 
> Bill Nobel
> 
>> On Oct 21, 2015, at 8:44 PM, Zippster <zippster278 at gmail.com> wrote:
>> 
>> Good point Bill, I’m definitely considering complete CoCo3 compatibility to be a must.  
>> 
>> A CoCo3 mode would be baseline operation for sure.  We will stick to normal GIME behavior and stock CPU speeds for that.
>> 
>> - Ed 
>> 
>> 
>>> On Oct 21, 2015, at 9:22 PM, Bill Nobel <b_nobel at hotmail.com> wrote:
>>> 
>>> You know what Ed, GO FOR IT…  You would be the one to do this.  One suggestion, make a mode switch like the 6309 to enable the enhanced features beyond the Coco3.
>>> 
>>> Bill Nobel
>>> 
>>>> On Oct 21, 2015, at 7:28 PM, Zippster <zippster278 at gmail.com> wrote:
>>>> 
>>>> Hi guys, these are a couple of cross posts from the Facebook group for people on the mailing list that don’t use Facebook.
>>>> I’m planning another project to follow the MC6847 FPG VGA boards, and there’s been a little discussion over there.
>>>> 
>>>> 
>>>> FPGA GIME PROJECT
>>>> 
>>>> I've started doing some of the prep work for an FPGA GIME chip replacement project. This is a stepping stone toward a CoCo4 project.
>>>> 
>>>> What I'm planning on is to develop a drop in board for the CoCo3 that will implement a GIME in FPGA, with 2MB of static RAM, and direct VGA out.
>>>> 
>>>> I'll be using an Altera Cyclone IV FPGA for the project. Since more I/O pins will be needed than are available on Cyclone IV QFP packages, this is going to require me to use a BGA256 packaged FPGA and a four layer PCB. Toward this end I have a reflow oven on the way, and I'm entering the needed parts into Eagle. This will give us quite a few pins to work with in implementing new features later.
>>>> 
>>>> This is going to be a very interesting and challenging project in several ways, but it's the big missing part of the puzzle hardware-wise to a fully CoCo3 compatible CoCo4, so hopefully it will be worth the effort.  :)
>>>> 
>>>> 
>>>> COCO FPGA EXPERIMENTER’S BOARD
>>>> 
>>>> As I've been entering parts preparing for the FPGA GIME project, I had an idea. With the work I'm having to do for that project, it would be relatively easy to develop an "FPGA Experimenter's Board" that would plug into the CoCo cartridge port along the way.
>>>> 
>>>> Kind of an FPGA development board that could be used for interfacing projects. With an Altera device, some bi-directional level shifters, maybe an ADC chip, a couple of resistor DACs, and some other support circuitry, we could have a pretty cool board for people interested in CoCo/FPGA projects. Maybe help get some more hardware developed.  :)
>>>> 
>>>> Is there enough interest in something like this for me to pursue it on the way to doing the GIME replacement?
>>>> 
>>>> What do you guys think?
>>>> 
>>>> 
>>>> - Ed
>>>> 
>>>> 
>>>> 
>>>> -- 
>>>> Coco mailing list
>>>> Coco at maltedmedia.com
>>>> https://pairlist5.pair.net/mailman/listinfo/coco
>>> 
>>> 
>>> -- 
>>> Coco mailing list
>>> Coco at maltedmedia.com
>>> https://pairlist5.pair.net/mailman/listinfo/coco
>> 
>> 
>> -- 
>> Coco mailing list
>> Coco at maltedmedia.com
>> https://pairlist5.pair.net/mailman/listinfo/coco
> 
> 
> -- 
> Coco mailing list
> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco