Welcome to PCjs, home of the original online IBM PC emulator for your web browser. The PCjs Project offers a variety of online computer emulators written in JavaScript, including PCx86 for x86-based machines (8088 through 80386), C1Pjs for the 6502-based Ohio Scientific Challenger 1P, PC8080 for 8080-based machines like Space Invaders and the DEC VT100 Terminal, PDPjs with support for PDP-10 and PDP-11 machines, and emulators of classic programmable calculators, like the TI-57. PCjs also provides an archive of selected historical PC software, publications, and reference materials.