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diff --git a/docs/random/img/shenzhen_io_review/canvas.png b/docs/random/img/shenzhen_io_review/canvas.png Binary files differnew file mode 100644 index 0000000..6961448 --- /dev/null +++ b/docs/random/img/shenzhen_io_review/canvas.png diff --git a/docs/random/img/shenzhen_io_review/sandwich_machine.png b/docs/random/img/shenzhen_io_review/sandwich_machine.png Binary files differnew file mode 100644 index 0000000..3259e07 --- /dev/null +++ b/docs/random/img/shenzhen_io_review/sandwich_machine.png diff --git a/docs/random/img/shenzhen_io_review/shoes.png b/docs/random/img/shenzhen_io_review/shoes.png Binary files differnew file mode 100644 index 0000000..03ed4ce --- /dev/null +++ b/docs/random/img/shenzhen_io_review/shoes.png diff --git a/docs/random/img/shenzhen_io_review/shoes_notch.png b/docs/random/img/shenzhen_io_review/shoes_notch.png Binary files differnew file mode 100644 index 0000000..55d8d2e --- /dev/null +++ b/docs/random/img/shenzhen_io_review/shoes_notch.png diff --git a/docs/random/img/shenzhen_io_review/shoes_wires.png b/docs/random/img/shenzhen_io_review/shoes_wires.png Binary files differnew file mode 100644 index 0000000..4321716 --- /dev/null +++ b/docs/random/img/shenzhen_io_review/shoes_wires.png diff --git a/docs/random/img/shenzhen_io_review/traffic_signal.png b/docs/random/img/shenzhen_io_review/traffic_signal.png Binary files differnew file mode 100644 index 0000000..d7ead83 --- /dev/null +++ b/docs/random/img/shenzhen_io_review/traffic_signal.png diff --git a/docs/random/img/shenzhen_io_review/traffic_signal_histograms.png b/docs/random/img/shenzhen_io_review/traffic_signal_histograms.png Binary files differnew file mode 100644 index 0000000..1e2f45e --- /dev/null +++ b/docs/random/img/shenzhen_io_review/traffic_signal_histograms.png diff --git a/docs/random/index.md b/docs/random/index.md index 7190d22..f670959 100644 --- a/docs/random/index.md +++ b/docs/random/index.md @@ -21,3 +21,4 @@ Nevertheless, occasionally I leave a permanent trace along the way. - [Playlist to put on on my deathbed](deathbed_playlist.md) - [Of Potato Chips And Food Globalization](potato_chips.md) - [2 Bugs 1 Day](2bugs1day.md) +- [Shenzhen I/O Game Review](shenzhen_io_review.md) diff --git a/docs/random/shenzhen_io_review.md b/docs/random/shenzhen_io_review.md new file mode 100644 index 0000000..e4287cb --- /dev/null +++ b/docs/random/shenzhen_io_review.md @@ -0,0 +1,268 @@ +# Shenzhen I/O Game Review + +I don't usually game.<sup>[citation needed]</sup> + +Sometime in 2021, in my first days of university, I felt bored and bought +this game. Also out of vanity to show how different I am from my league of +legends roommates. (it didn't work because i got stuck at assignment eight +and gave up, until december 2023 when i decided to give it another spin +now that i've made a few PCBs and written some assembly in real life) + +## What is this game + +[Shenzhen I/O](https://www.zachtronics.com/shenzhen-io/) is a "nerd puzzle +game" (my words) by Zachtronics. + +You move to Shenzhen and work as an employee at 龙腾 (Longteng), where you +combine chips into circuits that meet client specifications. In each level +(assignment), you are given a canvas like this one: + + + +Then you complete these tasks, in the general order: + +- Drag parts from the sidebar +- Connect parts with each other and I/O pins on the sides +- Write assembly for the programmable chips +- Simulate and debug until output matches expected waveform + +The assembly language in question is invented specifically for the game. +The chips are fictional, too. It doesn't actually require prior embedded +systems knowledge. A few differences from real-life embedded systems: + +- No need to explicitly power the chips +- No need to worry about clock cycles +- Everything seems to use decimal, not binary +- Hardly any boolean operations +- Voltage levels range from 0 to 100 +- ADC/DAC are perfectly accurate +- Integers range from -999 to 999 +- MCUs have two registers max (`acc` and `dat`), and no SRAM +- XBus, the asynchronous protocol, seems too complicated for one clock + cycle +- Multidriver problems are handled simply by `input = max({outputs})`, and + can be abused + +And mostly importantly, the debugger is something I wish I had in real +life. You can literally step through the instructions! Imagine if you were +able to freeze time, poke an ATmega328P and know which loop it's stuck in. + +That said, I'm not the best at this game. Hell, I'm not even _good_, as +I have created abominations like: + +<details markdown="1"> +<summary>Spoiler</summary> + +</details> + +After you complete each assignment, the game shows you where you are among +all the players. The data I got was: + + + +The current best for three metrics on the leaderboard are: + +- Lowest cost: 6 yuan (mine costs 20) +- Power usage: 123 (mine uses 1.7K) +- Lines of code: 9 (mine has 45) + +As you can see, my solution is far from good in whichever way, but +nevertheless it works. This is because there are so many ways to solve +a problem, and to optimize a solution. + +That said, am I going to optimize my solution? No. + +## Why is it fun + +Like all puzzle games, it is fun because it's intellectually challenging. +It's not the kind of Genshin Impact minigame. + +Another reason is the plot. For most of the game's target audience, living +in Shenzhen would be a foreign experience, and it's a lot of fun reading +coworkers (both Chinese and from abroad) react to projects and life. The +game's UI involves a mail client, where you receive emails from your +supervisors and coworkers, and honestly that's half the fun. + +(lets ignore the fact that most chinese companies dont discuss everything +over email) + +<details markdown="1"> +<summary>Spoiler alert!</summary> + +My favorite emails are: + +- When you designed a vape as merchandise for musician Cool Dad, who, once + the vapes were manufactured, got arrested for possession of + amphetamines. Also, Carl absolutely _roasted_ Cool Dad's music. +- When you designed a laser/illuminator apparatus for law enforcement + weapons and Carl responded with brutal sarcasm out of moral concerns. + I kinda wonder if the correct move is _not_ to design it, but it's too + late. +- When Joe proposed a haunted doll implemented with unmarked chips of + unknown origin, and was then forbidden from venturing further in the + field of "ghost electronics" +- When a Japanese company claims to have developed a "traditional yarrow + stalk _I Ching_ divination" with "MEMS technology" +</details> + +## Why is it hard + +### You have to read the datasheet + +The game comes with no manual; instead it ships a PDF containing all the +datasheets and supplementary materials. Fortunately they are much easier +to understand than those in real life. And they are (mostly) typeset very +well. Much more pleasant to the eye than many actual industrial +datasheets. In the one case it isn't, it's definitely intentional for +a "sketchy" vibe. + +### Chips are intentionally underpowered + +We know modern chips are extremely powerful. So powerful it would render +the game pointless. So the chips and assembly language in this game are +intentionally limited. The smaller chip only holds 9 instructions, the +larger one 14. + +I sometimes find it hard to implement any meaningful logic with such an +underpowered chip. Once I found a solution that was 15 lines long, but +I had to split them in two chips, and then I had to write extra code so +they could communicate, which is another 10+ lines of overhead. + +Hardware-wise, the chip has 6 pins max, and you can't just use _any_ pin, +because some pins are "simple", and some are "XBus". + +### Conditional instructions are cursed + +There's no actual "conditional branch". Give the chip a condition (e.g. +`teq acc 1` tests if `acc == 1`) and it sets a global state (+/-). Then +you can prepend a +/- to an instruction so that it only runs in the state. +The global state makes it really hard to emulate nested `if` statements. +Pretty sure there were actual ISAs that used this mechanism, but I always +get confused on this logic. + +### Labels count as lines? + +If you wanted to jump to an instruction, you have to label the line, like + +``` +loop: + add 1 + jmp loop +``` + +It should make sense to any programmer that labels are not real. They are +just a fancy way to refer to the line number it precedes, and thus should +not count as a line. But in the above code it does, because the text area +only has so many rows. This leaves me with one less line for actual +instructions. It took me way too long to realize that this is legal: + +``` +loop: add 1 + jmp loop +``` + +The datasheet never mentioned this! I was looking at the +[leaderboard](https://www.reddit.com/r/shenzhenIO/wiki/index/) when +I found out. + +### Canvas size is limited + +The wire traces take a significant amount of space and there is only one +side, so no vias. They will sometimes block pins. The only way to cross +two wires is to use a bridge, which only comes in one size and direction. +I have more than once made a circuit that looks like an absolute jumbled +mess. Like what even is this + +<details markdown="1"> +<summary>Spoiler</summary> + +</details> + +There was one level where I just _can't_ get the wires to go where they +should. I tried every direction possible to route the wires, but there's +either not enough horizontal space or enough vertical space. The most +disgusting thing is this kind of notch that you can't route wires through. +These notches made two hours of my life miserable. I almost gave up. + + + +Then I downloaded a solution from the leaderboard, only to find that, like +in real life, you can route traces _below_ the chips. _Nobody mentioned +that!_ There was nothing in the manual that explicitly said this was ok, +nor was there any hint in the game. The hack is only accessible if you +hold Tab, which enters "show wires" mode, and the chips become translucent +so you can route traces underneath. + +<details markdown="1"> +<summary>Spoiler</summary> +Normal view: + + + +When holding Tab: + + +</details> + +I doubt this assignment is possible without this kind of hack. Anyway, +I deleted the leaderboard solution and made my own version, and I'm never +looking back. + +## Hardest assignments + +These are a list of assignments that I felt stuck on for more than an +hour. + +<details markdown="1"> +<summary>Spoiler</summary> + +- Virtual reality buzzer (the level that led me to quitting in 2021) +- Precision food scale +- Traffic signal +- Color changing shoes (titled "Would you believe it?" in game) +</details> + +Again, I'm not good at this. If I had to find an excuse, it would be that +I try my best to come up with the most elegant solution possible, however +many lines it takes. I'd use a divide & conquer approach that's as +symmetric as possible, which is not always optimal, and sometimes uses up +too much of space and makes a mess of wires. + +## A nitpick on the awkwardness of languages + +The game is created by a bunch of Americans, for, I suppose, a primarily +English-speaking audience. Despite this, the game and the datasheets are +available in both English and simplified Chinese. The problems are: + +- The Chinese does not sound Chinese +- The English does not sound Chinese + +If you tried to play the Chinese version as a Chinese person, as I have, +you will find the Chinese dialog awkward. The translator did their best, +but it sounds un-Chinese. + +They are grammatically correct, but I find this sort of conversation out +of place in a Chinese workplace. However, I would prefer if real life +workplace conversations sounded like this. Light-hearted without much +客套话 (formalities). Let's hope society evolves that way. + +On the other hand, if you play in English, you'll find that your Chinese +coworkers have extraordinarily high English competency, atypical of +current day Shenzhen (but the game is set in the future, so one can hope). + +## Minigame: Shenzhen Solitaire + +Early in the game a coworker introduces a solitaire-style game with +Mahjong-themed cards. It's a way to relax when I'm stressed out solving +a puzzle. I like it so much that I [rewrote it in +Rust](https://git.sr.ht/~fkfd/shenzhen_solitaire). + +## Conclusion + +At the time of writing, I have not finished the game (yet). So far it's +really enjoyable. I did stress myself out a handful times halfway; that +was because I was not treating it as a game. Once I accepted the fact that +I'm just a casual player and being unable to solve the puzzles does not +result in any loss of self worth, I was again ready to have fun. |
