Background

My uncle passed away last year. He was the kind of guy who had a Slackware install before most people had email. He worked as a sysadmin for a logistics company most of his life, lived alone, never married, and was basically the “computer guy” for the whole extended family. When I was a kid he was the one who taught me to use a terminal. I think I was nine.

He got into Bitcoin really early. I knew that vaguely, because at family dinners around 2013 he’d sometimes say things like “I used to mine that on my laptop” and everyone would roll their eyes. Nobody took it seriously. He never talked about money and he lived pretty modestly, so honestly none of us know if he ever made anything from it.

My aunt (his sister) has been slowly going through his flat. A few weeks ago she rang me and said there was a box of “your kind of stuff” she didn’t know what to do with. Inside: a load of old hard drives, a Palm Pilot, about a hundred burned CDs labelled in Sharpie, and a ThinkPad T60 with a sticky note on the lid that said:

“MINER — DO NOT WIPE”

You can imagine how fast my heart was going.

The wallet (getting this out of the way)

https://www.blockchain.com/explorer/transactions/btc/0e7e171c308825c646400981dfec1cb6cada035be3103664541841824913ed8e

Yes, there was a wallet.dat. Yes, I loaded it up (on an air-gapped machine, before anyone lectures me). It’s empty. Completely. Looking at the transaction history, he moved everything out in a few chunks across 2011 and 2013. I have no idea where it went and I’ve made peace with it. RIP to my early retirement.

But that’s not why I’m posting.

The folder

Buried in his home directory, inside a folder called /misc/, there was a subfolder called /turtle/. Not “tortoise,” “turtle.” That’ll matter later.

Inside were:

• olddiff.txt, an ASCII tortoise
• RULES, a three-line text file
• logs/, a folder of 43 IRC log snippets dated October 2010 to June 2011
• shell.txt, which I’ll get to, because it’s the bit that’s driving me insane
• carriers.txt, a list of names

Let me go through them one by one.

1. The tortoise

This is olddiff.txt, exactly as it appears:

 ____ _/ () \_ / ____ \___ \_/ \_/ ' > '' '' OLD DIFF // 2016 

When I first saw “2016” I thought it was a date and that maybe he’d made this later. Then I checked the file metadata: last modified November 2010. Six years before 2016.

That’s when it clicked. Bitcoin’s difficulty retargets every 2016 blocks. Roughly every two weeks, the network looks at how fast blocks have been found and adjusts the difficulty up or down. It’s one of the core mechanics that makes the whole thing work. It’s slow, it’s predictable, and it’s basically unstoppable.

So “Old Diff” = old difficulty. And 2016 is the retarget interval. It’s a mascot for the difficulty adjustment itself.

2. The rules

The RULES file:

1. the tortoise only moves at retarget 2. never draw him running 3. whoever holds him last wins 

Rules 1 and 2 make sense once you read the logs. Rule 3 is the one I can’t stop thinking about.

3. The logs

These are where the story actually is. It looks like a small private IRC channel. I can’t find the channel name anywhere, and the logs just show timestamps and handles. There seem to be about 6–8 regular people. The handles that show up most are:

• kettlewick (this was my uncle; I recognise his typing style and some references to his job)
• n0nce_
• shellfish
• hashbrownz
• quietcoin
• vellum
• one or two others who appear only a handful of times

From what I can piece together, they were all mining at home on CPUs and early GPUs, mostly hobbyists, and they used the channel to share settings, complain about their electricity bills, and joke around.

The earliest log, from October 2010, has what I think is the origin of the whole thing. Paraphrasing slightly because some of it is messy:

n0nce_: diff went up again. this is getting silly
kettlewick: it’s not silly it’s the point. it only adjusts every 2016 blocks. it’s a tortoise. it doesn’t care how fast anyone is running
shellfish: the hare and the tortoise except the hare is every exchange that’s going to blow up
kettlewick: ha. someone draw it
vellum: [pastes the tortoise]
vellum: old diff. slow. armoured. undefeated

So it wasn’t even my uncle who drew it. It was vellum. My uncle just kept it.

After that, it became a ritual. From what I can tell, the rule was this: every time the difficulty retargeted, whoever in the group found the first block after the adjustment got to “carry” Old Diff. They’d paste the ASCII back into the channel with their handle written underneath, like this:

 ____ _/ () \_ / ____ \___ \_/ \_/ ' > '' '' OLD DIFF // 2016 carried by: hashbrownz 

And the rest of the channel would reply with stuff like “slow and steady” or “he moves.” There’s one log where quietcoin carried him three retargets in a row and everyone started calling him “the shell” as a joke.

4. “Never draw him running”

There’s a log from December 2010 that explains Rule 2. Someone new, a handle that only appears twice, zipzapr, posted an edited version of the tortoise with speed lines behind it, like he was sprinting. The channel did NOT like it.

shellfish: no
vellum: delete that
kettlewick: he doesn’t run. that’s the whole thing. if he runs he’s a hare and hares get rekt
n0nce_: the tortoise just keeps hashing
zipzapr: ok jeez

zipzapr never appears again. I genuinely laughed out loud reading it, but it also tells you how seriously they took the symbolism. Bitcoin wasn’t supposed to be fast. It was supposed to be relentless.

5. The June 2011 crash

If you know your Bitcoin history, you know the price went from around $1 to over $30 in mid-2011, and then completely collapsed after a major exchange hack. The logs from that period get dark. People were stressed. A couple of them sold. One person, hashbrownz, says he’s “done with all of this” and stops showing up.

Then there’s the last log. It’s dated late June 2011. Here it is in full:

vellum: retarget in a few hours
n0nce_: who’s even still mining
kettlewick: me. barely
shellfish: me
quietcoin: me
[about four hours pass in the timestamps]
shellfish: [pastes Old Diff with nothing underneath — no “carried by”]
shellfish: nobody carries him now. he walks on his own.
kettlewick: yeah
vellum: yeah

That’s it. That’s the final entry. No more logs after that date. I’ve checked every drive.

I don’t know why, but that last exchange gives me chills. It reads like they were retiring the mascot. Like they’d decided the network didn’t need them any more and the tortoise could keep walking without anyone holding him.

6. carriers.txt

This is just a list. My uncle seems to have kept a record of every “carry.” It has handles next to approximate dates (no block numbers, annoyingly). I count 19 carries total between October 2010 and June 2011.

The last line is just:

--- // he walks on his own 

7. shell.txt (the part I can’t explain)

This is the one that’s keeping me up at night.

shell.txt was last modified in 2019, eight years after the logs end. My uncle clearly opened this folder again years later and added something.

The whole file is this:

if you found this, you're the last one holding him. rule 3 still stands. look where the tortoise sleeps. the shell remembers what the hare forgot. — k 

That’s it.

“k” is obviously kettlewick, my uncle. “You’re the last one holding him” — I’ve read that maybe a hundred times now. Rule 3 was “whoever holds him last wins.” Is he saying I’ve won something? Is it just a sweet note to whichever family member eventually opened the laptop? Or is it an actual pointer to something?

“Look where the tortoise sleeps.” I’ve tried:

• every file on the laptop with “turtle,” “tortoise,” “shell,” or “diff” in the name
• the burned CDs (one of them is labelled “SHELL” but it’s just old Linux ISOs, as far as I can tell)
• the Palm Pilot (dead, ordering a charger)
• his old desk, which my aunt still has

Nothing yet.

“The shell remembers what the hare forgot.” I genuinely don’t know. Could be a pun on a command shell. Could be shell history. I checked .bash_history on the laptop and it’s been cleared, which honestly makes me more suspicious, not less.

And remember the folder is called /turtle/ and not /tortoise/. Everything else, he calls Old Diff a tortoise. Why name the folder differently? Am I reading too much into this? Probably. But I keep coming back to it.

What I’m asking

1. Has anyone ever heard of Old Diff? Did any of you hang out in a small mining IRC channel around 2010–2011 where this was a thing? I’ve searched everything I can think of and come up empty, which makes me think it really was just a private in-joke between a handful of people.
2. Does anyone recognise these handles? vellum, n0nce_, shellfish, quietcoin, hashbrownz. If any of you are still around, I would love to talk to you. Not about money. I just want to know what my uncle was like back then, and whether you remember the tortoise.
3. Any theories on shell.txt? “Look where the tortoise sleeps.” Puzzle people, ARG people, old-school sysadmin people, I’m all ears.

Why I’m posting this

I’m not selling anything. I’m not launching anything. I’m not trying to make money off a dead man’s in-joke.

I’m posting because I think this is a genuinely beautiful little piece of Bitcoin history, and it would’ve died in a cardboard box if my aunt had thrown it away. A handful of nobodies on CPUs and early GPUs, mining coins worth pennies, made a mascot for the most boring, most important part of the protocol and passed it around like a torch for nine months. Then, when everything crashed and they all burned out, they didn’t kill it. They let it walk on its own.

Fifteen years later, the difficulty still retargets every 2016 blocks. Exchanges have collapsed, projects have come and gone, every hare has been rekt a dozen times, and the tortoise is still walking.

Never draw him running.