[Coco] CoCoNet status

[Darren A]

On 12/29/08, Roger Taylor wrote:
>
> <snip>
>
> Another thing I noticed.  When you turn a CoCo on, it "transmits" a
> phantom character to the remote PC due to how BASIC sets up the PIA
> chips.  At some point a start bit is seen by the PC which leads to a
> byte being framed.  It could be that a break or partial break is
> transmitted.  I haven't looked further into it.
>

Upon Reset, all the PIA data lines act as Inputs. The bit-banger
output will likely go low at that time and the PC will see this as a
start bit (it could be considered a BREAK if it remains low long
enough). Color Basic (CoCo 1 and 2) sets the bit banger output to the
normal MARKing state fairly soon after reset (at address $A04F). The
CoCo 3 doesn't setup the output until after the initialization code
has been moved to RAM.

Darren