Understanding the Intel 4004 clock circuit
Noting that the Intel 4004 was normally sold as a chip set called the Intel MCS-4, the standard clock circuit used appears to be this (from this PDF, kindly provided by this vendor of MCS-4 test boards):
FastCDC, puzzlefs, and de-duplicating container and VM images
Since about 2017, a group at Cisco has been working on an “OCI native operating system” under the title “project machine”, which is a terrible project name. I note that most of the people publicly involved in the project according to github commits no longer work at Cisco, so I cannot vouch for the health of the overall project. That said, they did come up with some interesting ideas along the way and given its a quiet time of year I figured I could do some reading.
The Four Tendencies
I tend to be a bit concerned by psychology books from people without psychology qualifications, but Cat was keen for me to read this book based on her encounters of the author in podcast form. Luckily, Psychology Today seems to have relatively positive things to say about the book so I decided to give it a go.
Regardless, attempts to pigeonhole people into psychological buckets have always made me uncomfortable — be they Myers Briggs, Strengths Finder, or now the Four Tendencies. Ironically under the Four Tendencies framework I think that would make me a Questioner, but the (very short) analysis quiz declared me to be an Obliger. I am very sure my management chain at work would agree that if I am an Obliger I’m definitely hiding it pretty well. I’m not really sure what that means to be honest.
Psychology
Two Roads
May 3, 2018
257
Getting Vevor 7in1 weather stations working with rtl_433, MQTT, and Home Assistant
Please note: my Vevor weather station failed after a few months because of ineffective weather seals on the outdoor unit. Vevor is refusing to provide any sort of warranty on the item, so I would strongly encourage you to consider literally any other vendor’s product… In the end I bought a weather station from Jaycar which works just fine.
Now that we’ve defeated QNAP’s slightly broken udev, we can run a Docker container with rtl_433 in it to wire up our Vevor 7in1 weather station to Home Assistant via MQTT. First off, we need a Docker container running rtl_433, which assumes you’ve already setup the udev rule mentioned in the previous post, even if you’re not using a QNAP!
Configuring USB device pass through to Docker on QNAP NASes
So, this was a lot harder than it really should have been, especially because rtl_433 is a bit thingie about where the device appears in the /dev/ file system as an added sting in the tail…
In my specific scenario, I was given a Vevor 7-in-1 wireless weather station for Christmas. They seem fairly solid and full featured for a $130 AUD device, so no complaints there. The device is also natively supported by rtl_433 which is a RTL SDR package, although its not supported in the version shipped by Debian 12. That’s awesome, although it would have been nice if the command line to use was documented better. I’ll talk more about those bits in a later post though. In this one I want to focus on the fun I had getting a USB device reliably passed through to a Docker container on my QNAP NAS.
Remapping Keychron K15 (QMK) media keys to control Sonos
Disclaimer: despite what people seem to assume when you buy a mechanical keyboard, I am not a keyboard fetishist. I’ve been using Microsoft Sculpts for over a decade because of historical repetition injury issues, and with Microsoft discontinuing the Sculpt and the new manufacturer taking their time taking over, all I want is a keyboard which is like a Sculpt, except where I haven’t worn out the space bar. I will then go back to thinking approximately never about keyboards.
So, the keyboard I could find which was closest to the Sculpt after a lot of Googling was a Keychron K15 Max, which is a QMK keyboard. For those which don’t know, which included me until yesterday, QMK is the open source firmware that many of these mechanical keyboards run and yes you really can customize the firmware on your keyboard now. The K15 is a 75% “Alice” layout, which means split with no numpad. It does have media, function, and macro keys which is nice. I’ve never had a keyboard with macro keys before. It also has low profile switches, which is nice because the Sculpt basically has laptop style switches, and I chose the Gateron Brown low profile switches because I didn’t think I wanted the tactile “clicky” thing. Then again, I have now tried exactly one mechanical keyboard, so its entirely possible the K15 isn’t “perfect” for me — its simply good enough to make me stop thinking about such things.
An Anki deck for Cisco Cyberops Associate CBROPS 200-201
I’ve recently been going through the Cisco Cyberops NetAcademy course as part of a TAFE unit I am doing at the moment. While working through the e-learning I took a bunch of notes, and then over the weekend I turned them into an Anki deck to help me prepare for the final exam. I’m actually unsure if I’ll bother with the certification exam, but this seemed like a more useful and reusable way to prepare than just reading and writing private notes.
An easier to parse version of “yum history”
I got interested today in trying to come up with a solid way of determining when updates were last applied to a RHEL-derived Linux instance. Previously we’d been inferring it from the kernel version, but it turns out there is a convenient “yum history” or “dnf history” command which will show you all the previous transactions that the package database has seen. However, the output is hard to parse in a script.
Amazon Linux 2023, DNS, and systemd-resolved — a story of no caching
I’ve learned a few things on an adventure this week, and I figure I should probably write them down.
First off, AWS throttles the number of DNS queries you can perform on a VPC. Apparently you’re limited to 1,024 packets for Elastic Network Interface (ENI). I am a little unclear on if the limit is per instance ENI, or the ENI on the VPC that is the DNS server. I am also unsure if that’s 1,024 request packets, or 1,024 total packets, but either way there is definitely a limit after which you will be throttled.
Secondly, AL2023 disables the systemd-resolved DNS caching behaviour, which means its pretty easy to hit that throttling limit. When you google for solutions you’ll find re:Post posts recommending dnsmasq, which is a perfectly fine piece of software but not really necessary if you already have systemd-resolved installed on your instance (as you do with AL2023). (more…)
Leaders Eat Last
This is the first Simon Sinek book I’ve read. His stuff has been on my mental to do list for a long time, but never seemed to get to the top until now. This is about a book about how employee happiness and trust in their management directly results in better outcomes for employers, and how the best way to create happy employees is via mutual trust and empathy. In fact the book goes further and outright states that staying in a job that makes you unhappy, even if it also makes you feel safe, is bad for your health and eventually your life expectancy. I haven’t seen this stayed quite this clearly before and the book wastes no time in making this point.
Leaders Eat Last also has a section on the various chemicals in our brains and how they guide our behaviour. I felt specifically called out by this quote on the addictive nature of social media and how it interacts with our dopamine levels:
…if you wake up in the morning and the first thing you crave is a drink, you might be an alcoholic. If you wake up in the morning and the first thing you do is check your phone to read email or scan your social media before you’re even out of bed, you might be an addict.
How very aligned with Digital Minimalism. Now in my defense, the first thing I check in the morning is the state of outstanding GitHub pull requests so I guess I’m not a social media addict?
Biography & Autobiography
Penguin Books
2017
350
Leaders eat last : why some teams pull together and others don't is the much anticipated sequel to the global best seller, start with why by Simon Sinek. This book talks about how great leaders sacrifice their own comfort for the good of those in their care. With the help of numerous intriguing examples, the author attempts to prove that the best organisations foster trust and cooperation. As the author points out, this book is not a management theory, but it actually a biological one. Individuals thrive only when they feel safe among a group.