>I'd imagine that the printer
>would be a Data Set device, as most computers are Data Terminal
>Devices..... I'd expect the DSR being the printer/modem's way of
>saying its ready and the DTR being the computers sign that its
>ready....

Not correct. Both a terminal and a printer are terminals. Therefore to
conect them together you need a crossover cable. A dataset is a modem.
Modems assert DSR.

Lets summarise the true situation:
Terminals and printers Assert DTR and RTS.

Modems assert CTS and DSR.

Peter Bancroft