SuperCOSMOS Image Analysis Mode (IAM) data consists of a set of 32 parameters for every astronomical image located on the measured photograph. A dataset typically contains data for a significant fraction of a million objects. Various standard SuperCOSMOS programs are able to work with IAM datasets, but it is expected that SuperCOSMOS users will frequently write their own programs for accessing their data. This document describes the standard form in which IAM datasets are stored on disk, and provides examples of how to access them.