Are all the different Casio cables compatible?
No, there are two different types, one with a 2.5mm plug and one with a 3.5mm plug. The one with the 2.5mm plug incorporates a voltage converter which connects a diary port operating at 6 volts to a PC serial port operating at 12 volts. The one with the 3.5mm passes 12 volts from the PC serial port straight through to the diary – so don’t try to use a plug size adapter to make the wrong cable fit your diary! There are a variety of different designs for the voltage converter in the 2.5mm cable (see Compatibility)- the important difference is that the cables which need to draw power from the serial port don’t always agree on which pins should be +12v and which pins should be -12v. In particular, the Travelling Software cable and the Yellow Computing cable require the reverse voltages on RTS and DTR. The voltages on these pins have to be set by software, so the software has to know which type of cable you are using to be compatible with all cables. Most software packages assume a Travelli
