[Coco] rs232/bitbanger in MESS?

[Robert Gault]

John W. Linville wrote:
> On Tue, Dec 01, 2009 at 06:18:28PM -0500, Aaron Wolfe wrote:
>
>> I'm going to keep messing with this (pun intended) :)  Would be very
>> useful to have a serial port in an emulator.
>
> That's pretty much what that code I sent you does, although it
> doesn't pretend to be a 6551.  It does however handle a couple of
> addresses in the emulated address space and connects them to a PTY
> on the Linux side.  I find it very useful. :-)
>
> The MESS 6551 emulation seems to be modeling the behavior of the
> 6551 as seen by the CPU.  But like you, I could never see that it
> actually did anything to communicate outside of the emulator itself.
> I don't know how that is useful to anyone other than as an exercise
> in hardware emulation, but whatever...
>
> It probably wouldn't take much effort to take the code I sent you and
> refactor it to more closely model the "user interface" (i.e. register
> set) of the 6551 to that you could use 6551-aware CoCo programs to
> talk to the outside world unmodified.  It's just a SMOP... :-)
>
> John

I've got a question about this in to the MESS team but in the meantime ....

MESS permits sending data through the bitbanger but you can only attach 
files that emulate printers. Clearly the data sent to $FF20 bit-1 is 
going out of MESS but the main question is it going only to a file 
emulating a printer or is it also going to the printer port?

If MESS sends data to both the PC printer port as well as files, then we 
can build printer to serial cables and talk to external hardware.