[Coco] Color BASIC Printing

Darren A mechacoco at gmail.com
Fri Oct 15 22:59:56 EDT 2010

On 10/15/10, tim lindner  wrote:
> I've been digging into this a little.
> Before printing color BASIC will test RS232-in (bit 1, of port b, of pia
> 1) waiting forever until it is low. My guess is Tandy printes did infact
> set this low.
> If you connect a modem to the serial port, it will leave that signal
> high becuase that's what they normally do. And this will cause BASIC to
> hang before attempting to print.
> And all this is by design?
> --

When connected to a printer,  the CD line on the serial port is used
as CTS.  When the printer's buffer is full it raises the line, causing
the CoCo to suspend transmission.

I would imagine a modem could use the line in the same way or use it
for CD as originally intended.  It all depends on the software (and
cabling).   Of course, Color Basic has no integrated support for modem
communication, just printer output.


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