[Coco] DW and 6551

[Darren A]

On Tue, Feb 10, 2015 at 8:52 PM, Aaron Wolfe <aawolfe at gmail.com> wrote:

> In theory a UART would be a lot more efficient than the bitbanger.
> However, in reality, Darren's awesome bitbanger routines are so much faster
> than the 6551 can go that it doesn't work out that way in this particular
> situation.
>


Actually the 6551 can do 115 kbps.  All you have to do is configure the
baud rate generator to use the External Clock setting. This will cause the
bit rate to be equal to 1/16 the crystal frequency.  The RS-232 Pak has a
1.8432 MHz crystal (1,843,200 / 16 = 115,200).

The only real question is whether or not the level shifting circuitry in
the Tandy pak can operate at that speed.

- Darren