Most Linux and Unix operating systems come with XScreenSaver, which consists of a large collection of graphical demos. The entire collection has now been available for iOS and iPadOS for a while, nice to try out!
First the ‘bad’ news: neither iPad nor iPhone have a screensaver function. After all, it would be a waste of battery capacity! Instead of a nice animation, these devices jump to sleep mode and the associated black screen. Don’t worry: the graphic highlights from the app XScreenSaver do it on it, so you can watch it for hours without further ado.
If you want the ‘real’ screensaver functionality, you have to switch to a Linux or Unix system. Or install the also available XScreenSaver for macOS. However, in this article we focus on the iPad/iOs app XScreenSaver (there is also a version for Android by the way!). Because despite the fact that this is actually more of a graphical demo, most of the individually available ‘screensavers’ still have quite a bit to tweak.
Applications can also be devised in this more limited form. Connect your iPad or iPhone to a TV and create psychedelic party background wallpaper. When iOS/iPadOS 16 appears soon, the full potential of the external screen will also be used.
Already 30 years old
XScreenSaver dates from 1992 – 30 years old again – and was developed by Jamie Zawinski. It has been actively maintained by the same maker ever since. It has always been open source and thus free, even in app form.
By the way, Zawinski is more or less a legend in the IT world. He worked on the Netscape browser and adjacent mail program, among other things. He has also owned a nightclub in San Francisco since 1999. All in all, one of the more colorful figures. Something that is clearly reflected in XScreenSaver.
After installing the app, you will be presented with a long list of available screensavers. The year of issue is stated everywhere, so you can also see when the first 3D video cards appeared on the market. However, creative programming made sure that 2D screensavers are a joy to watch from the very beginning.
Technical-scientific viewing pleasure
Modern hardware – including tablets and smartphones – usually doesn’t care about the math behind it, resulting in buttery-smooth animations. You start a screensaver by simply tapping on its name. If you want to view the setting options first, tap the circled i. There are many options for each screensaver.
Many of the screensavers also have a scientific background. Think fractals, gears, gravitational fields and more. Furthermore, for most available screensavers a link to more explanation and background is available. In short: if you want you can also learn something from it.
For the computer nerd, for example, the screensaver m6502 is very nice. This emulates a 6502 cpu, an illustrious 8-bitter that had its heyday in the home computer era. Nice detail: it is still produced and used in toys, for example. Anyway, the screensaver version is thus an emulator that runs programs continuously.
Via the settings you can specify the desired number of instructions per second; Basically they are fine as they are. Unless you want to emulate an ultra-fast CPU, of course. The image is shown on a similarly emulated CRT TV, including some noise.
Terminal with news value
Phosphor is at least as retro as the aforementioned screensaver. It is a terminal emulator that displays random texts from Wikipedia. A very nice detail is that if you have XScreenSaver running on macOS or Unix, it can also be started as a program. In that case it behaves like a full-fledged VT-100 terminal!
Instead of the default Wikipedia articles you can also enter your own URL in the settings. You will soon notice that in most cases you will see HTML code. What appears to work fine is to enter an RSS feed as URL in the appropriate field in the settings, for example try https://www.nu.nl/rss/Algemeen for a continuous stream of current general news .NL.
Incidentally, there is also the Apple ][ emulator, als screensaver gestart gewapend met een slideshow en ook random ingetikte programma’s die vervolgens uitgevoerd worden. Start je deze deze screensaver op bijvoorbeeld je Mac als losse app, dan gedraagt ook dit stukje software als een volwaardige terminal. Altijd handig om achter de hand te hebben, zo af en toe.
Fractals
Zoals al gemeld ontbreekt het aan fractals verre van in XScreenSaver. Kijk bijvoorbeeld eens naar IMS Map, voor wolkachtige patronen. Je kunt trouwens van alle getoonde beelden op de bekende manier screenshots maken; daarmee zijn (onderdelen van) gegenereerde graphics wellicht ook weer te gebruiken in eigen creaties.Â
Hopalong is een ‘klassieke’ fractalgenerator, goed voor lang tijdverdrijf. C Curve genereert lijngebaseerde fractals, die heel simpel beginnen maar al snel uitgroeien tot complexe figuren.
Van nul tot nu
In XScreenSaver trekt een ruim stuk computergeschiedenis aan je ogen voorbij. Voor de ‘oude rotten’ zal het tenminste deels een feest van herkenning zijn, en voor ieder ander is het gewoon leuk om naar te kijken in een verloren uurtje. Waarbij je je moet bedenken dat álle screensavers in een app zijn gevat van slechts 20 MB groot. Daar is op ieder apparaat dus wel een permanent plekje voor te vinden, gokken we!
.