[Coco] [Color Computer] USB Anyone?

[James Diffendaffer]

--- In ColorComputer at yahoogroups.com, Phill Harvey-Smith <dragon at a...>
wrote:
> James Diffendaffer wrote:
<snip>
>  >
>  > 1 PAL/GAL + 2 74HCT373 chips would handle all the logic for USB, IDE
>  > and interfacing a ROM.
> 
> 
> Had you considderd using something like one of the Xilinx CPLDs, 
> something like an XC9572XL, this chip runs on 3.3v so will interface 
> directly to the usb chip, but has 5V tollerent IO, so will also 
> interface directly to the CoCo/Dragon bus without level shifters.

No need, the USB chip is 5V tolerant (See section 4.3.2 of the
SL811HS.pdf file).  The only reason I'd go with a PLD of any kind
would be to reduce the board size.  I was thinking adding the IDE
might require 2 extra chips for address decoding, bringing the total
chip count 6 + USB + IDE connector.  That wouldn't fit in a small
cartrige easily.  Now I think I can reduce that and get it to fit if
the USB part isn't too big.

>  > My biggest roadblock is having to create a prototype board for the
<snip>
> Depending on what PCB software you are using I have a library that I 
> made that contains the Dragon/CoCo edge connector. 

Well, I have been trying to decide between FreePCB, Eagle, and PCB
123.  (No matter what program I use I seem to run into bugs)
I'm sure I could find a way to convert it no matter what format it's in.






Brought to you by the 6809, the 6803 and their cousins! 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/ColorComputer/

<*> To unsubscribe from this group, send an email to:
    ColorComputer-unsubscribe at yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/