spectrums.jar-(old)-forge-1.20.1.jar is a beta file of the Minecraft mod SPECTRUMS for Forge, made for Minecraft 1.20.1. It was published on March 21, 2025 and is 4.3 MB in size. Pre-release builds can contain bugs — back up your world before installing. For the full description, screenshots and every other version, visit the SPECTRUMS mod page.
How to install: Put the .jar into the mods folder (.minecraft/mods) and start Minecraft with the matching mod loader profile.
