Running a Computer Without RAM

An exploration of running a computer with minimal or no RAM. Starting with Linux swap files on SATA SSD and VRAM (via a FUSE filesystem over OpenCL), the experiment shows severe performance degradation. The deeper dive covers CPU cache-as-RAM using the open-source CoreBoot firmware: by intercepting CoreBoot's early initialization stage, a small program (a Snake game) runs entirely in CPU cache on a 2009 ASRock motherboard with no RAM sticks installed, outputting via serial port. The experiment reveals that the CPU on that board doesn't cache ROM, so it reads instructions directly from BIOS flash, explaining the poor performance.