A1 has the "external control" switch in the power dial. What is it for?
The reason why I ask this question is as follows:
I attempted to access the SD card in A1 through this switch from the computer.
The computer said I need a drive program to do so.
How can I have access from a computer to the SD card which is still installed in AI?
I have no SD card reader. Your advice would be appreciated.

You *NEED* a card reader to access your stills on the card. However, you can access the PRESET dir on the card when you have a piece of software from Canon, called Console 1.1 - you can control your A1 with it (and the switch position you mention is just for that). This software can also access (read/modify/store) the custom preset files on the card.

Thank you very much for your explanation.

Just to Clarify, it would be cheaper to buy a usb sd card reader than get console.