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Six transistors,
three states,
and ten decades of waiting.六个晶体管，
三个状态，
和十个数量级的等待。

Three figures about the same small thing, each demonstrating a way of drawing that generalises well beyond it. A ladder that opens every symbol before it uses it. A triptych that keeps one geometry and moves only the colour. A rule that fits ten decades on one axis without lying about the gaps. If a page has to explain a mechanism, these three between them will usually carry it.三张图，讲的是同一件小东西，而每一张示范的画法都远不止用在这件小东西上。一条在使用每个符号之前先把它打开的阶梯；一组保持同一套坐标、只让颜色移动的三联图；一把把十个数量级放进一根轴、又不在间距上撒谎的尺子。一个页面要讲清一个机制，这三张通常就够了。

6transistors in the cell the ladder arrives at阶梯最后到达的那个单元用了几个晶体管
3panels sharing one set of coordinates共用同一套坐标的格数
10⁹the span the log rule has to hold对数尺要装下的跨度
what is checked and what is representative哪些是查过的，哪些是示意

There are no kernel paths on this page, so there is nothing here to grep — which is worth saying plainly rather than leaving the reader to assume the numbers were verified. The circuit is the standard six-transistor cell; the transistor counts are exact for that arrangement. Every timing figure is a typical order of magnitude and the ruler says so on its face: the point is the distance between them, never the digits. Measure your own part before quoting any of it.这一页没有内核路径，也就没有什么可以 grep 的——这句话值得直说，而不是让读者默认那些数字都核过。电路是标准的六管单元，晶体管数对那个结构来说是准确的。所有时间数字都是典型数量级，尺子上也这么写了：要看的是它们之间的距离，永远不是那几位数字。要引用之前，先测自己那颗器件。

A symbol nobody has seen opened is a symbol nobody will question.没被打开过的符号，读者不会去质疑它。

Every technical page runs on abstraction, and every abstraction is a box somebody decided to stop drawing the inside of. That decision is usually invisible: the reader meets the triangle already closed, learns the rule for using it, and is stuck the first time a variant does not behave. The fix costs one panel. Draw what is inside, then fold it up in front of the reader, and put the price on the outside of the fold so nobody forgets what the convenience cost.任何技术页面都靠抽象运转，而每一个抽象都是有人决定不再画里面的那个盒子。这个决定通常是隐形的：读者遇到那个三角形时它已经是关着的，学会了用法，然后在遇到第一个不按常理出牌的变体时卡住。补救只要一格图。把里面画出来，再当着读者的面折起来，并且把价钱写在折起来的外面，这样没人会忘记这份方便花了多少钱。

OPEN IT FIRST, THEN CLOSE IT INTO A SYMBOL each panel opens the symbol the panel before it handed over. a symbol nobody has seen opened is a symbol nobody will question. 1 two transistors one pulls up, one pulls down WHAT IS INSIDE THE SYMBOL YOU THEN USE supply ground out in 2 transistors the triangle is not new information — it is the pair above, folded up. 2 two of them, in a ring each one feeds the other WHAT IS INSIDE THE SYMBOL YOU THEN USE high low neither one can change without the other disagreeing. so it stays. 1 bit that holds no clock, no refresh 4 transistors the box is worth 4, not 1. that number is the price of the abstraction. 3 a way in and out two more, opened by a word line WHAT IS INSIDE THE SYMBOL YOU THEN USE word line · opens both at once bit line bit line the ring is the same ring. the two new transistors only decide when you may look. one memory cell addressable, at last 6 transistors multiply by a few million and you have the cache the die photo is mostly made of. a wire held high a wire held low “everything above, folded into this” a reader who has seen a symbol opened will question it later. a reader who met it already closed will copy it, and will be stuck the first time the variant does not behave. every symbol carries its transistor count, so the ladder never hides what an abstraction costs — which is the number that decides whether it is used a million times. Abstraction ladder · open, then close
open it first, then close it先打开，再折起来 The ladder never hides what a level costs: two transistors, then four, then six, printed on the symbol itself. That number is the one that decides whether a thing gets used a million times or not at all, and it is exactly the number an abstraction is best at concealing.这条阶梯从不隐藏每一层的价钱：两个、四个、六个晶体管，直接印在符号上。这个数字决定了一样东西会被用一百万次还是根本不会被用，而它恰恰是抽象最擅长藏起来的那个数字。
the symbol arrives already closed符号一上来就是关着的
The reader will copy it correctly and will not be able to reason about it. That is fine right up to the first variant, and then it is not fine at all, because they have no model to fall back on — only a shape they were told to trust.读者会正确地照抄它，但没法对它做推理。在遇到第一个变体之前这都没问题，之后就全是问题，因为他没有可以退回去的模型——只有一个别人叫他相信的形状。
the cost is left off the symbol符号上没写代价
Then every level looks equally cheap and the reader has no way to feel the difference between a thing used once and a thing repeated a few million times across a die. Print the count on the symbol. It is one pill and it changes how the figure is read.那每一层看起来都一样便宜，读者也就感觉不到「用一次」和「在一块 die 上重复几百万次」的区别。把数目印在符号上。那只是一颗药丸，却改变了整张图的读法。
the ladder has five or six rungs这条阶梯做了五六级
Three is usually the limit before the reader loses the thread of what contains what. If the material needs more, break it into two figures with a shared bottom rung, so the second one starts from something already understood.三级通常就是极限，再多读者就跟丢了「谁装着谁」这条线。内容确实需要更多级时，拆成两张图，让第二张的第一级就是第一张的最后一级——这样它从一个已经懂了的东西开始。

Keep the geometry still and let the colour move.让几何不动，让颜色动。

The usual way to show three states is three drawings, and the usual result is that the reader re-finds the circuit three times and never notices which parts actually changed. Lock every coordinate instead. Now the eye has nothing to re-parse, the difference is the only thing left moving, and a legend fixed once for the whole figure does the rest. The cost of this method is discipline: the moment one panel gets nudged for a better fit, the whole effect is gone.展示三个状态的常规做法是画三张图，而常规结果是读者把电路重新找了三遍，却始终没注意到到底哪部分变了。把每一个坐标都锁死。这时眼睛没有东西需要重新解析，唯一还在动的就是那个差别，剩下的交给一个对整张图只写一次的图例。这个方法的代价是纪律：只要有一格为了排得好看被挪了一下，整个效果就没了。

THREE STATES, ONE GEOMETRY · ONLY THE COLOUR MOVES the three panels share every coordinate on purpose, and read left to right as one story: the cell holds a zero, a write turns it into a one, then a read gets that one back out. holding nobody is touching it word line bit line · QB side bit line · Q side Q QB the word line is not asserted both access transistors are shut. the ring keeps itself, and holds a zero at Q. writing the drivers win word line bit line · QB side bit line · Q side Q QB the bit lines are driven, and Q flips a write is not persuasion — it is overpowering the ring from outside. Q is a one now. reading the cell barely whispers word line bit line · QB side bit line · Q side Q QB −50 mV both bit lines start high; one dips QB is the low node, so the QB-side bit line is the one that sags. that sag is the entire signal. high low nobody is driving it the word line is asserted a figure redrawn for every state hides which parts moved. a figure recoloured for every state shows it, and the reader stops re-reading the schematic three times. the colour meanings are fixed once for the whole figure. a legend that changes between panels is worse than no legend at all. fifty millivolts is a typical order of magnitude for a cell like this, not a measurement — the point is that it is small, not that it is fifty. State triptych · recolour, do not redraw
three states, one geometry三个状态，一套坐标 The three panels also read left to right as one story: the cell is holding a zero, a write turns it into a one, and a read gets that one back out as a fifty-millivolt sag on a single bit line. Ordering the states as a sequence rather than a menu costs nothing and gives the figure a direction.三格从左到右也读成一个连贯的故事：单元里存着 0，一次写入把它变成 1，一次读出把这个 1 取回来——表现为某一根位线上五十毫伏的下沉。把三个状态排成一个序列而不是一份清单，不花任何代价，却给了这张图一个方向。
the discipline this method needs这个方法要求的纪律

A legend that changes between panels is worse than no legend在几格之间会变的图例，比没有图例更糟

Colour is carrying the entire argument here, so its meaning has to be fixed once for the whole figure and stated where the reader will look. If orange means high in one panel and “selected” in the next, the reader learns to distrust the colour and starts reading the labels instead — at which point the figure has become a slow table.这里颜色承担了全部论证，所以它的含义必须对整张图只定义一次，并且写在读者会看的地方。如果橙色在这一格是「高电平」、在下一格变成「被选中」，读者就学会了不信任颜色，转而去读标签——到那一步，这张图已经退化成一张慢吞吞的表格。

Ten decades do not fit on a linear axis. They barely fit on a page.十个数量级放不进线性刻度。放进一页纸都很勉强。

The cell on this page answers in about a nanosecond. A round trip across a continent takes a hundred and fifty million times longer. Those two numbers belong in the same picture, because the whole craft of making a machine feel fast is knowing which of them you are standing next to — and a linear axis puts eleven of the twelve points on top of each other at the far left, which the small strip at the bottom of the figure shows rather than claims.这一页讲的那个单元，大约一纳秒就能答。一次跨洲往返要长一亿五千万倍。这两个数字属于同一张图，因为让一台机器「感觉快」这门手艺，全部在于你清楚自己此刻站在哪一个旁边——而线性刻度会把十二个点里的十一个叠在最左边，图底下那条小尺子把这件事show 出来，而不是说出来。

ORDERS OF MAGNITUDE · TEN DECADES ON ONE AXIS every step to the right is ten times longer. that is the only way twelve numbers spanning a factor of 150 million fit in one picture. 1 ns 10 ns 100 ns 1 µs 10 µs 100 µs 1 ms 10 ms 100 ms 1 s L1 hit branch mispredict uncontended lock one DRAM access one syscall context switch NVMe random read eMMC random read same-rack round trip spinning-disk seek one frame at 60 Hz cross-continent the only one a person can perceive processor memory storage network what your eye is waiting for THE SAME NUMBERS, IF ONE NANOSECOND WERE ONE SECOND L1 hit 1 ns 1 second one DRAM access 80 ns 1.3 minutes one syscall 500 ns 8 minutes NVMe random read 50 µs 14 hours one frame at 60 Hz 16.7 ms 193 days cross-continent 150 ms 4.7 years THE SAME TWELVE POINTS ON A LINEAR AXIS · WHY THIS FIGURE IS NOT LINEAR 0 150 ms eleven of the twelve land on this one mark these are typical orders of magnitude, not measurements — the point is the distance between them, not the digits. measure your own board before quoting any figure. a log axis has to say so on its face: equal spacing means times ten, and a reader who misses that reads every gap as ten times too small. the human-scale row is what turns the ruler into an argument. “a hundred thousand times slower” is a phrase; “one second against a hundred and ninety-three days” is a picture. Magnitude ruler · log scale
ten decades on one axis一根轴，十个数量级 The human-scale row is what turns the ruler into an argument. “A hundred thousand times slower” is a phrase; “one second against a hundred and ninety-three days” is a picture. The one anchor that is not a machine number is the frame at sixty hertz, because it is the only interval on the axis a person can actually perceive.「换成人类尺度」那一排，才是让这把尺子变成论据的东西。「慢十万倍」是一句话，「一秒 对 一百九十三天」是一张图。轴上唯一一个不是机器数字的锚点是 60 Hz 的一帧，因为它是整根轴上人真正能感知的唯一一段间隔。
a log axis that does not say it is one对数轴上没写它是对数轴
Then the reader takes every gap at face value and reads the whole figure ten times too flat, without ever getting a signal that something is wrong. Say “each step is ten times” on the face of the figure. It is one line of text and it is not optional.那读者会按字面读每一段间隔，把整张图读平十倍，而且完全不会收到任何「哪里不对」的信号。在图上写明「每一格是十倍」。那只是一行字，而且不是可选项。
the numbers are given to three digits数字给到了三位有效数字
Precision here is a promise you cannot keep — these are orders of magnitude and they move with the part, the temperature and the queue in front of them. State that on the figure, and the reader will use it for what it is good for, which is deciding what to worry about.在这里给精度是一个你兑现不了的承诺——这些是数量级，会随器件、温度和前面排的队一起变。在图上写清楚，读者就会拿它去做它擅长的事：决定该担心什么。