A blast from the past

Oisin Mulvihill — Sun, 12 Jan 2020 18:06:06 GMT

At least 3 start-ups have been built on this!

My trusty Mid 2012 MacBookAir needed a reinstall after many years of service. I duly backed-up. Then rebooted doing the two finger recover mode salute (⌘ + r). A format, reboot and another two finger salute later I was the proud owner of 10.7 OSX Lion!

Oh dear :(

I attempted to install 10.15 Catalina from the App Store. Sadly this didn’t work. It requires 10.9 Mavericks as a minimum. I tried finding it but it was long gone. I could possibly get it from somewhere shady, but who knows what “extra” might come with it.

Lots of searching later I finally came across this thread on the Apple support https://discussions.apple.com/thread/250966496. I needed to download 10.11 El Capitan and then upgrade to Catalina after, phew!

As it was downloading I wondered if I could also download all the files I need for 10.15 Catalina. I came across this interesting article on how to do this https://7labs.io/tips-tricks/macos-catalina-direct-download.html. It didn’t work, but it was close. I spent way longer then I should have figuring out what was wrong :) I discovered you must download the files:

328B AppleDiagnostics.chunklist
2.9M AppleDiagnostics.dmg
104B AppleDiagnostics.dmg.integrityDataV1
2.0K BaseSystem.chunklist
475M BaseSystem.dmg
1.8K BaseSystem.dmg.integrityDataV1
 10M InstallAssistantAuto.pkg
140B InstallAssistantAuto.pkg.integrityDataV1
 26K InstallESDDmg.chunklist
7.1G InstallESDDmg.pkg
 26K InstallESDDmg.pkg.integrityDataV1
1.5K InstallInfo.plist
781K OSInstall.mpkg
104B OSInstall.mpkg.integrityDataV1
477M RecoveryHDMetaDmg.pkg
1.8K RecoveryHDMetaDmg.pkg.integrityDataV1

From:

I created the following folder structure on my Desktop:

macos_local/content/downloads/24/50/061–10700-A_RGVHHKO7O2/ht647isnxisi6xcjx58vib39t7rmgsy3es/

I copied all the files into “ht647isnxisi6xcjx58vib39t7rmgsy3es/”. I ran the magic web server, which would pretend to be Apple, inside the “macos_local/” folder from the Terminal:

python -m SimpleHTTPServer 80

I edited the “/etc/hosts” as the article suggested. I ran “Install macOS Catalina.app” and Hey Presto it was ready for reboot some 10 minutes later. Sometime after that, I had Catalina back. Huzzah!

Success!

With luck this will help someone else. In theory I should also download El Capitan for the next time. But it was very late at this point and time for bed. Don’t forget to undo the “/etc/hosts” change.

Joys of building

Oisin Mulvihill — Sat, 28 Dec 2019 18:38:54 GMT

The magic in action

I like sparkling lights and making things. I remember my Dad introducing me to electronics from an early age. Together with my sister we’d put together one of those early electronic kits. I still remember building a crystal radio and being amazed that it worked.

I now hold a degree in Electronic Engineering from Dublin City University. I graduated in 2000. Near the end of my course, I realised I didn’t want a life of chip design as I saw it. Electronics took a long time to get right. I liked building things quickly and rapidly iterating. I discovered software engineering gave me this. So I side stepped into it and never looked back.

I haven’t built a single electronic circuit since I graduated. I even forgot the red wire is for positive voltage! I decided to regain some hard earned knowledge and bought the ”ELEGOO Mega 2560 Project The Most Complete Ultimate Starter Kit”.

It has been great fun wiring all the components and programming the Arduino. I’ve even come up with my own project to show the temperature, humidity and the “comfort level”. You can check this out on my Github here.

Its important to find time to play and do things like this. It reminds me of the simple joys of putting something together and seeing it work, without having a deadline or reason to do so. This reconnects me with earlier times and gives me a break from the busy humdrum of modern life.

Stories by Oisin Mulvihill on Medium

A blast from the past

Joys of building