View Full Version : Control of the ATN / DTR line ...From the BS2 vault ..."mouse" emulator (MOU

Beau Schwabe
03-04-2005, 06:10 AM
This post is in reference to .... BS2 SEROUT freeze when Hyperterminal connects to com port (http://forums.parallax.com/showthread.php?p=527941)
and other relating topics.

Several years ago I wrote a BS2 application that "emulates" a serial MOUSE.
I knew that on some machines that the DTR line could be at an unpredictable state
upon powerup. So I wrote two DOS assembly programs.... One that would force
the DTR line high, and another that would force the DTR line low to accommodate
my mouse emulator.

Moustamp Program:
Moustamp.zip (http://www.hth.com/filelibrary/BS2-IC/Moustamp.zip).
....I'll try to find my original program. Everything looks ok, but for some reason
it has been stripped of all of the coments.

If you have an application that needs to talk to the stamp and you have the option
in your application to SHELL to DOS, then the two programs "might" be an alternative
option to using the capacitors.

A little bit of History:
Originally the BS2 programming board did NOT have the two capacitors on the ATN/DTR
line. Through a few E-mails between Jon Williams and myself, the capacitor solution
was conceived.

Beau Schwabe - Mask Designer III

National Semiconductor Corporation (http://www.national.com/)
(Communication Interface Division)
500 Pinnacle Court, Suite 525
Mail Stop GA1
Norcross,GA 30071

Post Edited (Beau Schwabe) : 3/3/2005 10:39:17 PM GMT