[Coco] Hello Aaron help dragon

[Phill Harvey-Smith]

On 17/05/2011 15:55, Darren A wrote:
> On 5/16/11, Aaron Wolfe  wrote:
> The 8 data lines of the Dragon's parallel port are wired for output
> only, so you can't do bi-directional parallel I/O.  It should be
> fairly simple to connect an inexpensive TTL to RS232 level shifter
> module to a few of the pins on the parallel port, creating a
> high-speed bit banger port adapter.  There are 2 input pins on the
> parallel port (ACK and BUSY*) which could be used along with any one
> of the outputs to achieve 115200 bps using the new technique in DW4
> (turbo).

I believe that I checked this and the only thing you should need is to 
make a level shifter, I think the PIA pins that the CoCo uses as bitbang 
inputs are ACK and BUSY on the Dragon. So yeah I think that a simple 
MAX203/232 adapter would be suffient, there's even a +5V output on the 
Dragon paralell port to run it from.

Cheers.

Phill.