Offimg Gallery

created October 18th, 2023 • 1m reading time • 11 views

Screenshot of Offimg Gallery

The DM42 calculator SwissMicros uses a memory LCD display, which means the image persists after power off. Because of this, you can have it display an image on the screen when turned off. Each image is a 1-bit 400x240 bitmap file, and the SwissMicros forum has a section dedicated to posts about these offimages.

In 2022 a member made a post asking for someone to make a website to list all of these offimages on a single page, so you could just scroll through instead of opening and scrolling through every post. After seeing this post in fall of 2023,

How It Works

The scrapper first finds every post on the OFFIMG board, and then finds all images and links to zip files. After opening the zips, all the images that are 1-bit 400x240 bmp files are saved to disk. An additional info.json is also created that holds information like the original post url, alt text, and post date.

On the frontend now, we just load the info file, loop through all of its entries and make a new image and show some of that data under it. Finally, I made a cron job to automatically re-run the scraper every month to include any new offmages.


All in all this project only took a few hours, but it looks like people are actually using it, which is cool. The site was even linked to on the HP Plus RPN Calculator Comparison Table under the DM42. I think this makes me famous.