[Coco] Prototype cartridge board?

[computerdoc]

Hi Don,
I worked on a Coco Prototyping board quite a while back, I don't think
I ever fabricated one. I actually had forgotten about it until I
read your email. It is a full size cartridge prototyping board with
enough logic to decode addresses. I designed it in Eagle Pro. I was
using a different laptop 5+ years ago so I will need to setup the
software on this new one. When that is done, I'll get back with you and
we can go from there.How does that sound? 
Kip KoonCoco Enthusiast
On Sat, 2022-08-06 at 22:26 -0400, Don Barber via Coco wrote:
> Hi folks,
> I recently soldered together my own Altair 8800 (
> https://barberd.medium.com if you're interested). Part of that
> involved building a Serial IO board (
> http://s100computers.com/My%20System%20Pages/Serial%20IO%20Board/Serial%20IO%20Board.htm
> ) that includes a DLP-USB245R (
> https://www.dlpdesign.com/usb245r-ds-v10.pdf).
> Using this USB module on the Altair is working so well for me that
> now I'm considering building a CoCo cartridge with one. The USB
> protocol takes care of all the speed/parity/stop settings so no need
> to worry about that anymore, and the module itself can buffer quite a
> bit of data, freeing up the CPU from needing to constantly poll the
> serial port to not lose data. And one doesn't need to deal with usb-
> rs232 adapters for the modern PC side of things; it just a straight
> cable and shows up as a new COM device in Windows or ttyUSBX device
> in Linux.
> I think I can make it mostly-compatible with the Deluxe RS232 Pak
> with not much effort. I say mostly-compatible as the module does not
> have an equivalent to the local echo configuration available on the
> RS232 Pak's 6551 chip. One could recreate that behavior with a bunch
> more logic chips and a register chip but it doesn't seem worth it.
> As such, i'm wondering if there is any source for a prototyping board
> for the coco 40 pin cartridge port? What do you hardware hackers use
> when playing with a design for a new cartridge-based peripheral for
> the coco?
> I was thinking something like this: 
> http://s100computers.com/My%20System%20Pages/Prototype%20Board/Prototype%20Board.htm
> (scroll all the way to the bottom for the latest design) of course
> with the right 40-pin connector instead of the S-100 connector.
> If it turns out such is not available, and I'm not informed of a
> better way to go about things: were I to design such a prototyping
> board and order a run, would others be interested in getting in on
> the order?
> Don
> PS: Listened to the recent CocoTalk segment talking about my RSA
> program. I suppose I should be proud that it ended with an
> 'ASPARAGUS!!!' ?
> 
> 
>