Database optimization
“坚持从实际出发、按规律办事”
，更多细节参见搜狗输入法2026
4. For the Z80 implementation, I did zero steering. For the Spectrum implementation I used extensive steering for implementing the TAP loading. More about my feedback to the agent later in this post.
When VM=1, the protected-mode bit goes low and the Entry PLA selects real-mode entry points -- MOV ES, reg takes the one-line path. Meanwhile, CPL is hardwired to 3 whenever VM=1, so the V86 task always runs at the lowest privilege level, under full paging protection. The OS can use paging to virtualize the 8086's 1 MB address space, even simulating A20 address line wraparound by mapping pages to the same physical frames.