Logisim includes an integrated hex editor for viewing and editing the contents of memory. To access it, bring up a pop-up menu for the memory component and select Edit Contents.... For ROM components, which have the memory contents as part of the attribute value, you can alternatively access the hex editor by clicking the corresponding attribute value.
The numbers in italics at left display memory addresses, written in hexadecimal. The other numbers display values starting from that memory address; the hex editor may display four, eight, or sixteen values per line, depending on what fits in the window. To help with counting, each group of four values has a larger space between.
You can navigate through memory using the scroll bar or using the keyboard (the arrow keys, home, end, page up, and page down). Typing hexadecimal characters will alter the currently selected value.
You can select a range of values by dragging the mouse, shift-clicking the mouse, or navigating through memory with the keyboard while depressing the shift key. Values may be copied and pasted using the Edit menu; the clipboard can also be transferred into other applications.
Next: User's Guide.