These are some of the great textbooks to teach #UNIX #OS to #CS undies:

• V6, Lions
• SVR2, Bach
• MINIX3, Tanenbaum
• Xinu, Comer
• xv6 (V6 clone), Cox

But there is a space to create an even smaller, sleeker, simpler, study OS:

• Barebones 32-bit OS that runs on a cheap Cortex-M3 board (STM32 Blue Pill) or RISC-V board (ESP32-C6)
• Keep the code under 10k lines of C (or Ada, Rust, Zig, ...)
• Support only UNIX-like soft-realtime scheduling (no RTOS)
• Support user and kernel modes
• Multiplex the single-core CPU to multiple processes
• Map a handful of interrupts to signals
• Provide a subset of the POSIX API, just enough to run a simple I/O executable (button pushy/LED blinky) in multiple processes, simultaneously
• Single-user (root only) operation
• No security, accounting, etc.
• Shell on a terminal emulator, via a USB-TTL adapter

The goal is to create a smallest, simplest, bona fide OS for the cheapest ($0.99) hardware, so as to steer kids away from Scratch, MicroPython, Processing, and similar other harmful influences, during the early phase of their system #programming education.

To make explicit the implicit premise above, the marvellous Arduino teaches the kids to do the easy thing repeatedly, but a comparative-joke C64 forces the kids to do the right thing persistently.

It is infeasible to teach, in detail, the essentials of an OS (scheduling algorithms, process management, memory management, memory protection, authentication, authorisation, encryption, disc I/O, network I/O, graphics I/O, ...) in just one semester.

In contrast, the kids could master the above mentioned focused curriculum in just one semester, thereby gaining much confidence in system #programming.

Change Default Linux/Unix Image Viewer Application

Use this complete guide to change the default image viewer application for a graphical desktop environment on a GNU/Linux or Unix operating system.

https://www.adamsdesk.com/posts/change-default-linux-unix-image-viewer/

#blog #KDE #XFCE #GNOME #linux #unix #tech

Alt...

Rays of light scatter down and outward through the blue and purplish water in the background. The foreground is made up of a group of three polaroids spread out like playing cards each with their own image viewer logo in the centre along with a strong title of 'Set Your Default Linux/Unix Image Viewer'.

Apple is so user friendly. You know you need this special macOS app that will prevent iTunes or Apple Music from launching when you connect headphones by default. One of those little annoying things that Apple thought you don't need any option to disable default behaviour. The source code is available and you can install it with: `brew install --cask notunes`

Stop the Music app from launching on macOS:

a) Music Decoy https://github.com/FuzzyIdeas/MusicDecoy
b) noTunes https://github.com/tombonez/noTunes

#unix #apple

Please don’t be shocked, but I’ve been reading old #UNIX Review magazines on Archive.org, as one does. I’ve been finding a number of interesting artifacts throughout. This June 1984 ad by Cadmus Computer Systems listed a #USENET address: !wivax!cadmus.

This is a UUCP bang path, for the kids who don’t know. The ! separates relay hops, it’s a literal routing instruction. Get to the backbone, reach wivax, forward to cadmus.

No DNS.

Machines screamed at each other to swap data.

#unix_surrealism

Alt...

A man works on a computer with multiple monitors displaying graphical data, surrounded by an advertisement for Cadmus computer systems.

Alt...

A vintage advertisement for the Cadmus 9000 computer system, highlighting its complete set of tools and contact information.