The Select Range dialog can be used to select a set of continuous bytes by specifying a starting address and a number of bytes, or a start address and an end address. To open the dialog, click the 'Edit > Select Range...' menu option, or press Shift+Ctrl+A. If the Select Range dialog is opened when a selection is already made, the dialog with display the start address and size (or end address) of the current selection.

By default, the dialog specifies selections using a Start Address and a Size field. The Start Address field of the dialog displays the address of the first byte of the selection. If no selection is made, the address will be the current cursor position. The Size field displays the number of selected bytes. If no bytes are currently selected, this field shows the last number of bytes selected with this dialog. The Hex and Decimal radio buttons control which format is used to display the fields. Click the OK button to make a selection, or the Cancel button to close the dialog.

Alternately, selections can be controlled using a Start Address and an End Address. To enable this mode, click the Options button and enable the Specify Range using Start Address + End Address toggle. Enter the address of the end of the selection in the End Address field (note that the Size field disappears). For example, entering a Start Address of 1000 and an End Address of 1005 would select 5 bytes (the byte at the end address is not selected).

When a selection is made, the start address and size of the selection are displayed in the status bar. See the Status Bar help topic for more information.