Indev i8080 microprocessor simulator and assembler
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.

Molasses 70s style logo

Build Status Code Climate Test Coverage size size

MolassOS is an operating system simulator that can run in your web browser. Currently I'm in the stage of building the hardware emulator.

The operation codes and assembly instructions are exactly what the Intel 8080 uses. The Assembler uses the Intel 8080 assembly mnemonics. A lot of the modules are designed using the i8080 microprocessor and the Datapoint 2200 programmable terminal as guidance.


You need Nodejs and grunt-cli installed globally to build MolassOS. The tests do not take long to run so the default task builds and tests the application. The following with

npm update
npm install grunt

Modules are planned to be built in the following order. This is subject to change

  1. src/hardware/ > MolassOS.cpu
  2. src/asm/ > MolassOS.asm
  3. Use MolassOS.asm to assemble contents of src/os/ into floppy.json
  4. Bundle MolassOS.cpu and contents of floppy.json into MolassOS.emu
  5. If not a sdk build delete MolassOS.asm

Sources and Further Reading

  • wikichip
  • OS Dev Wiki
  • DataPoint 2200 introductions
  • BDS C source code
  • NASM source code : excellent docs and source comments, highly recommended
  • The DataPoint 2200 Programmer's Manual (1971, Intel corp.)
  • The Intel 8080 Assembly Programming Manual (1975, Intel corp.)
  • Intel 8080/85 Assembly Language Programming (1977, Intel corp.)
  • Crash Course / PBS's Computer Science YouTube series
  • Code Climate for the free student account