Unless you’ve been hiding under a rock for more than 20 years, you’ll encounter the matrix series and the cool green “digital rain” effect often used. This aroused [oli Wright]’s curiosity. What would it look like if we didn’t run animation on modern displays, but used digital phosphor persistence effects, but implemented on some retro PC hardware and used actual high persistence phosphor green monochrome displays. (Video Embedding, below) fortunately, [oli] has a 40 year old IBM PC 5150 and a matching IBM 5151 display, so it is a simple thing to implement this effect in the 8088 assembler to create a falling sequence of characters. The last binary file is less than 256 bytes!
The long display persistence of IBM 5151 aims to reduce the visibility of display flicker caused by low scan rate, but its unfortunate side effect is that it will cause serious smearing when the image changes. This is exactly what [oli] needs to achieve this effect, and we think it looks very good.
[oli] uses the excellent Emulator Based on pcjs browser written by [Jeff Parsons] to demonstrate the function of the software, but the effect is not obvious. If you like, you can try it yourself, because the list of assemblies can be found in the GitHub project.
Of course, we have reported many digital rainfall effects. For example, many times before this arduio library, there is a customized PC chassis side plate, starting from December 2021, if you can remember those days.