commit e627fca7dc382e721d7e6364fd31c8c221dea494
parent 6bbecb9b6d8e78869530d01cf5489d984a9c42df
Author: Eamon Caddigan <eamon.caddigan@gmail.com>
Date: Tue, 12 Dec 2023 20:51:00 -0800
December Adventure, day 12
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diff --git a/content/december-adventure/2023-12/index.md b/content/december-adventure/2023-12/index.md
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+---
+title: "2023, Day 12"
+date: 2023-12-12T18:55:04-08:00
+draft: false
+---
+
+[Devine had a sharp critique
+today](https://merveilles.town/@neauoire/111568838011217063):
+
+> Reading the december adventure feed, nearly halfway into the month, you'd
+> expect people to have started to play with stuff, but the feed reads like
+> most are lost in the weeds of setting their servers or environment and
+> whatnot so they can finally begin. For a chillout event, it looks
+> exhausting af
+
+So I _have_ been hacking for the past week, but I've also been grouchy and
+whiny enough the past couple days that I _feel_ exhausting af[^jumps].
+
+Since Eli's whole vision for December Adventure is that it should be [fun
+and playful](https://eli.li/2022/12/9/december-adventure), I decided it
+seemed fun to work on a different part of my project: how should I encode
+the Morse code representation of each character[^fun]?
+
+In case anyone is unfamiliar with Morse Code, it's a method of encoding
+characters with signal durations (dots and dashes, or as radio folks call
+them, dits and dahs), each letter is represented by one to four dits or dahs
+(numerals are all represented by five). At first it seems obvious to use one
+bit per dit/dah, but it's a little tricky due to the varying length for each
+character.
+
+The solution I landed on was using two bits per dit/dah, with another two
+bits to indicate the end of a letter:
+
+bits | signal
+-----|--------------
+`01` | dit
+`11` | dah
+`00` | end of letter
+`10` | (unused)
+
+This allows each character (including numerals) to fit into a 16-bit short.
+Slightly over half of the letters would be able to fit into a byte, but by
+using a short for each one, implementing a lookup table will be much easier.
+Another shortcut I plan to take is to store the letters' encoding
+"backwards", with the first dit/dah in the lowest bits. This should let me
+play the tones for a character with a simple sequence of _shift_ and _and_
+operations.
+
+I haven't actually implemented anything yet, but I had fun thinking this
+through, and I look forward to coding this up!
+
+[^jumps]: In the same thread, they also helped me work through some
+ questions about addressing that I had [yesterday]({{< ref
+ "december-adventure/2023-11/index.md" >}}); thanks!
+
+[^fun]: Look, this kind of thing is _fun_ to me, ok?
