[Coco] Embedded coco

[jdaggett at gate.net]

Eric

Thanks

Pads for a header will be fine for the expansion port.

I am not familiar with PCB123. I have used a few before. for home use and my 
senior project I used Ivex Windraft and Winboard. At work Mentor (YUK) and 
Cadence tools. Those are well beyond the price of hobby use. I think the Cadence 
WnXP tool set for schematic capture and PCB layout starrts at $10K and goes up 
from their. My former employer was paying $2000 per year per license above the 
base cost of $30K. That ran on a Sun Sparc 10 or above. . 

Putting together a kit or teirs of kits is not a real problem. Just needs someone to 
invest some time and money to get PCBs and parts together and bundled. 

I have a bunch of TC55257's and a few LH6158s floating around and both are 
100nS sram. Fine on the SRAM. Refresh is a pain and Digikey has 512Kx8 25nS 
Sram for around $10 to $12 each. 70nS for about $5 each. One can still find old 486 
tag ram floating around cheap.

james
 
On 18 Dec 2003 at 10:47, peak at mail.polarcomm.com wrote:

> James
> Those are good questions!
> As to what kind of ram I was thinking of static ram because 
> that would eliminate refresh. The size of ram would be 
> optional. For a start I probably would use just one 6116 chip 
> which would give 2KB. As to Rom I would start with a 2716 or 
> 2764 with the Intel pinout.
> 
> As to the coco's expansion port my Idea is to put jumper pads 
> on the ckt board so that a person could add a full coco 
> expansion port if desired.
> 
> The main Idea here is to design a board with optional 
> connectors and interfacing so that individuals might 
> customize it depending on their own desires for embedding 
> a "coco type" computer.
> 
> Layout : I only have "PCB123" layout software at this time so 
> that is what I will use but I also plan on publishing just a 
> schematic so if you wanted a different layout you could.
> I will design this thing with lots of options though. The 
> board could have solder pads for surface mount components as 
> well as the older type plated through hole pads for sockets.
> The sizes of ROM/RAM,number of PIA's,Inclusion of a DAC chip,
> and or Cartridge connector will all be optional.
> 
> I hope this answers your questions and I am open to 
> suggestions. If there is enough interest in a mini-coco then 
> perhaps we could make it a community project and convince 
> cloud 9 or someone to produce a kit. It could be made 
> available as just a bare ckt board or a ckt board with 
> connectors etc.
> 
> Thanks for your input!
> Eric the Technician.
> 
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