It is easier for a software program to view a hard drive as a large serial memory object than as a physical device with heads and cylinders. The records start at address 0 and go to some large number. However, at some point in the software this linear addressing must be changed to a three vector address that includes the sector, head, and cylinder so that the data can be read and written to the hard drive. The flowchart above describes a software subroutine that would increment a three vector address.

First download the free trial version of RFFlow. It will allow you to open any chart and make modifications.

Once RFFlow is installed, you can open the above chart in RFFlow by clicking on basic_flowchart1.flo. From there you can zoom in, edit, and print this sample chart. It is often easier to modify an existing chart than to draw it from scratch.

The above flowchart uses one of the flowcharting color schemes. To find these, click the More Shapes button, Flowcharting, and Color Schemes in RFFlow.