[LMG S13] Issue 161: Security and XSS
Previously: A content delivery network comprises multiple servers around the world that are able to quickly distribute static content (typically images and...
[LMG S13] Issue 160: CDNs and content distribution
Previously: Instead of GPS satellites, smartphones can also use wifi points and cell towers to determine their position (if enabled in the OS). All...
[LMG S13] Issue 159: Wifi & cell tower location tracking
Previously: To get your location using GPS, your phone requests information from four overhead GPS satellites: their location, and the distance between them...
[LMG S13] Issue 158: GPS
Previously: Time is synchronised from higher-precision sources through a protocol called Network Time Protocol (NTP). A public pool of time servers is...
[LMG S13] Issue 157: NTP and time-syncing
Previously: To speed up execution and avoid translation overhead, some systems employ ahead-of-time translation, storing the translated instructions to be...
[LMG S12] Issue 156: Translation
Previously: Translating a set of instructions before executing it will always lead to a slowdown, although sometimes this may not be noticeable to users. So,...
[LMG S12] Issue 155: Emulation performance
Previously: Programs that were not compiled for the instruction set of the host OS have to go through an emulation layer program. This program translates the...
![[LMG S12] Issue 154: Emulation](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season12/issue154/issue154_01.png)
[LMG S12] Issue 154: Emulation
Previously: The cloud offers standard digital business services, accessible through a web interface and API, which any developer (with a credit card) can...
![[LMG S12] Issue 153: Using the cloud](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season12/issue153/issue153_01.png)
[LMG S12] Issue 153: Using the cloud
Previously: Actually making a web application requires you to set up lots of supporting software and carry out lots of steps to create a suitable app...
[LMG S12] Issue 152: Getting started with programming
Previously: The Java Runtime Environment (JRE) bundles the Java VM and supporting libraries. The JRE has to be installed on the user’s system for Java...
[LMG S12] Issue 151: the Java VM
Previously: System VMs provide a set of virtualised hardware that the OS interacts with. Process VMs provide a set of libraries that a program (written in...
[LMG S12] Issue 150: System VMs vs Process VMs
Previously: Containers are one layer of virtualisation above virtual machines: containerisation systems virtualise access to the operating system, presenting...
[LMG S12] Issue 149: History of commercial computing - containerisation
Previously: Renting out virtual hardware instead of physical hardware meant that instead of having to move hardware around and manage it, you could send the...
[LMG S12] Issue 148: History of commercial computing - cohosting
Previously: Running a virtual machine is like running a physical machine, but within a window in your OS. Co-located hosting A not-so-long time ago, to run a...
![[LMG S12] Issue 147: Operating systems on virtual hardware](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season12/issue147/issue147_01.png)
[LMG S12] Issue 147: Operating systems on virtual hardware
Previously: Virtual hardware can be created in the form of drivers that respond to a program’s requests for hardware resources. If a bootup program...
![[LMG S12] Issue 146: Virtual hardware](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season12/issue146/issue146_01.jpg)
[LMG S12] Issue 146: Virtual hardware
Previously: Programs do not usually deal with the gnarly details of hardware, but instead access it through an interface. They access storage devices through...
[LMG S12] Issue 145: What an app wants, what an app needs
Previously: In 1999, VMware launched VMware Workstation, which allowed multiple operating systems to run off a single machine. In Season 5 (Issue 53), I went...
[LMG S12] Issue 144: Programs-in-a-vat
Previously: The Apple M1 is a souped-up iPhone processor, with unified memory. I want to circle back to talking about processors again in this season,...
[LMG S11] Issue 143: Implications (Part 2) – Future Goals
Previously: Using the same hardware for both smartphones and laptops would make it much easier to write apps for both platforms. The closer they are in...
[LMG S11] Issue 142: Implications (Part 1) - Software
Previously: The Apple A14 and Apple M1 are essentially the same chip architecture: they use almost the same building blocks, just with different numbers of...