Poking memory
You can manipulate the contents of memory using the Poke Tool, but the interface for this is severely limited by space constraints: For more than the simplest editing, you will probably find the integrated hex editor far more convenient.
Nonetheless, to view and edit values within the circuit, the Poke Tool has two modes of operation: You can edit the address displayed, and you can edit an individual value.
To edit the address displayed, click outside the display rectangle. Logisim will draw a red rectangle around the top address.
Typing hexadecimal digits will change the top address accordingly.
Typing the Enter key will scroll down one line.
Typing the Backspace key will scroll up one line.
Typing the space bar will scroll down one page (four lines).
To edit a particular value, click the value within the display rectangle. Logisim will draw a red rectangle around that address.
Typing hexadecimal digits will change the value at the address currently being edited.
Typing the Enter key will move to editing the value just below it in the display (down one line).
Typing the Backspace key will move to editing the value at the previous address.
Typing the space bar will move to editing the value at the following address.
Next: Pop-up menus and files.