How to use the lab

1. Look around: drag to orbit, scroll to zoom, right-drag to pan.
2. Build: in Guided mode the next part glows in the parts bin on the right. Drag it onto the green target and let go; it seats itself.
3. Read: click any part or connector for what it is and what it does.
4. Go inside: double-click the installed CPU to open the chip, then a core to see its ALU, instruction logic and caches.
5. Run the bus: click the copper traces between the CPU and memory and press Run fetch–execute to step through the cycle.
6. Menu: the left panel lists everything by topic — build steps, parts to open, simulators (blue) and labs — plus a self-test per topic.
7. Performance and arithmetic: the CPU has the Amdahl / CPI / SPEC lab; the ALU inside a core has two's complement, multiplication, division, IEEE 754 and number-system converters.
8. I/O and the OS: click the chipset for programmed / interrupt-driven / DMA transfers animated on the bus; click the CPU or a memory module for the scheduler and paging labs.
9. Memory hierarchy: open a memory module (DRAM cells, refresh, Hamming code), a cache block inside a core (mapping, hits and misses), the hard disk (platters, seek and rotation timing, RAID) or the SSD (page writes and block erases).

Instruction cycle on the system bus