The main window has three areas:
1. Menu bar (top, 34 px):
- File - create, open, save, import/export
- MP-System - execution control and reset
- Help - this help window and about dialog
2. Left panel - structural diagram:
- Processor registers with live values
- Multiplexer, instruction decoder, ALU
- Tact/cycle indicators
- Quick Access panel - device buttons
- Speed panel - execution tempo selector
3. Right panel (330 px):
- RAM contents table (address/value/command)
- RAM cell editor, Register editor
- Execution and Reset button groups
Status bar at the bottom shows current state.