A recent demonstration showed the impressive ability to download Linux on a personal computer called the Commodore 64, which was produced in the 1980s. This achievement was made possible by utilizing the SMU system emulator and the mos 6502 microprocessor.
The SMU emulator, which features a RISC-V processor, was used to run Linux on the eight-discharge microprocessor of the Commodore 64. The emulator was assembled using llvm-mos, a software based on LLVM that allows for the development of modern programs in C++ for outdated processors.
Due to the limited 64 KB RAM in the computer, a memory expansion unit (Reu) and virtual memory emulation with MMU were employed. Loading the Linux kernel on the RISC-V emulator took approximately a week, while launching the emulator, composing an email, and creating a screenshot took a few hours. However, through the use of optimizations, the load time was eventually reduced to 39 hours. Further optimizations are expected to improve the emulator’s performance by about 10 times. Additionally, the emulator can utilize the already loaded state of the emulated system to eliminate the long loading process.
