Even if you are lucky enough to own a Casio interface for your programmable calculator, it can very frustrating trying to get it to work. (I know from experience!) There is very little help in the User Manual, regarding PC connection.
However, it is possible to make your own PC-Casio connection cable or even transfer programs between two Calculators.
Four core BT telephone cable is an ideal substitute and is coloured to aid identification.
The PC Connection is made to the Parallel Printer Port (LPT1). Using a special connector available at most good PC shops or Computer fairs, the wires may be attached to pins and located into the connector at the following locations.
PC Connector viewed from the Cable side
The corresponding wires should be inserted into the following holes of the Casio Socket. I have not come across a source for Casio connectors. Please let me know if you know different!
The wires should be connected as follows...
DATA BIT 0
To commence communications between the PC and your Casio, it is necessary to download this Interface Program: