You can bring up a ruler utility at any time by selecting it from the functions menu, or by pressing the ALT_R key sequence. The ruler can be moved with the up and down arrow keys. You can calibrate it with the left and right arrow keys. To put the ruler away press the ALT_R key sequence again. The ruler utility makes it easy to count the number of bytes between two characters on the screen.
SI_SCOPE will display an ASCII chart when you choose the "Display ASCII Table" option from the Actions Menu. Use the PGUP and PGDN arrow keys to scroll through the table. Press ESC to return to the SI_SCOPE window.