Alexey Ratcheson wrote: > Is a DB 25 pinj male-to-male the same as an RS322? The DB-25 connector is the standard one used for RS-232, but there are other options, including DE-9 (as typically used on modern PCs). The gender of the connector (male or female) depends on the devices involved in the connection. Another major factor is whether the cable is "straight through" or "crossover". RS-232 defines two standard device types: DTE (Data Terminal Equipment, e.g. a printer) and DCE (Data Communication Equipment, e.g. a modem). These device types use opposite directions for each signal. For example, a DTE transmits data using pin 2 of a DB-25 connector, while a DCE receives data using pin 2. A "straight through" cable is typically used to connect a DTE to a DCE. A "crossover" cable is typically used to connect a DTE to another DTE (or a DCE to another DCE). Most computers are DTEs, so you typically need a crossover cable to connect a computer to a serial printer (also a DTE) and a straight through cable to connect a computer to a modem (DCE). The Apple II Super Serial Card is somewhat unusual because it can act as either a DTE or DCE by reversing a jumper block on the card. This means that if you have the wrong type of serial cable, you can often get away with it by reversing the jumper block. One final point is that while the data signals are well defined, the flow controls signals have widely varying meanings and you might run into problems with particular cables not connecting the flow control signals correctly between the two devices. -- David Empson dempson@actrix.gen.nz