Data Transfer Ready / Data Terminal Ready - one of the Extended Hayes command set.
Very DTR is likely part of the squawking heard when one 1200 baud modem says hello and does the hand-shaking when connecting to another modem across a dial up telephone line. Remember when a Hayes 1200 baud modem was cool? Actually DTR is when you switch to speaking directly to the modem in a manual fashion I think.
av hazie 8. desember 2007