[Coco] Simple, reliable routines for the bitbanger serial port?

[Darren A]

On 3/15/09, John W. Linville wrote:
> Anyone have a set of simple (and tested) routines to do
> one-character-at-a-time transfers through the CoCo's bitbanger port?
> I don't need high performance, although 9600bps might be nice.
> I'd prefer routines that only used hard-coded timing loops (i.e. not
> interrupts) just for simplicity sake, but any working code is welcome.
>
> Can anyone help?
>
> Thanks!
>
> John
> --


John,
The bit banger routines I provided to Boisy for DriveWire 3 can be
viewed/downloaded from the CVS repository:

Read code:
<http://nitros9.cvs.sourceforge.net/viewvc/nitros9/nitros9/level1/modules/dwread.asm?revision=1.2&view=markup>

Write code:
<http://nitros9.cvs.sourceforge.net/viewvc/nitros9/nitros9/level1/modules/dwwrite.asm?revision=1.2&view=markup>

The first routine in each file is for 38400 bps and will work on any
CoCo.  These may provide more functionality than you need, but they
are tested and could easily be dumbed down/slowed down for whatever
purpose you require.

Darren