What is published
CHIP-8 is a complete interpreter for the 1977 virtual machine used on the COSMAC VIP: 4 KB of memory, sixteen registers, a 64 × 32 display and a hexadecimal keypad. It includes a small assembler, so you can write and run your own programs, and a debugger that steps one instruction at a time and shows registers, stack and disassembly. The bundled programs were written for this page.
Proscenium applies the same idea to services. It reproduces webhook behaviour on your own machine through scripted response sequences, synthetic events and loopback replay, so integrations can be tested without sending traffic to a hosted service.
Why emulation
An emulator is a precise statement of how a machine behaves. Writing one forces every ambiguity in the specification into the open: when timers tick, how a sprite collision is reported, which flag an instruction sets. That precision is also what makes emulators useful for teaching architecture and for testing software against hardware that is hard to obtain.
Next steps under study
Cycle-level emulation of a 1980s 8-bit CPU and video chip is listed as a concept under study. It is not built.
Published 25 October 2026. Questions and corrections: [email protected]