Simple Save (New for BIFF7 and Later)

Microsoft Excel 95 and 97 use a new simple save method from OLE 2, which was developed to increase performance. If a workbook contains no Visual Basic modules, no PivotTables, and no embedded objects on worksheets, then Microsoft Excel uses the simple save method.

When Microsoft Excel saves a workbook using simple save, the streams in the file must be at least 4kbytes long. The OLE 2 code adds padding bytes to the streams to ensure that they are at least 4kbytes long. If you use a low-level binary viewer (instead of the BiffView utility) to examine the resulting file, you will see the padding bytes appearing as "garbage" at the end of the streams.

To find the actual end of the Book stream, you can increment a counter every time you read a BOF record and then decrement it every time you read an EOF record. When the counter reaches zero, then you have read the last EOF in the Book stream and you can ignore the rest of the bytes in that stream.