Firmware, RomWBW

To summarise RomWBW, I’ll quote Wayne Warthen, author of RomWBW:

RomWBW is a ROM-based implementation of CP/M-80 2.2 and Z-System for all RetroBrew Computers Z80/Z180 hardware platforms including SBC 1/2, Zeta 1/2, N8, Mark IV, RC2014, and Easy Z80. Virtually all RetroBrew hardware is supported including floppy, hard disk (IDE, CF Card, SD Card), Video, and keyboard. VT-100 terminal emulation is built-in.

The RomWBW ROM loads and runs the built-in operating systems directly from the ROM and includes a selection of standard/useful applications accessed via a ROM disk drive. A RAM disk drive is also provided to allow temporary file storage.

Source: https://github.com/wwarthen/RomWBW

RomWBW is freely available on github , together with source code and documentation.


If your hardware supports RomWBW and you want to run CP/M, I recommend you use RomWBW. The hardware requirements are primarily:

  • A Z80 Family CPU
  • 512k bytes ROM
  • 512k bytes RAM

Optional hardware:

  • Asynchronous serial port(s)
  • Compact Flash for mass storage
  • SD card for mass storage
  • IDE hard drive for mass storage
  • Real time clock
  • Keyboard
  • Video display unit

System based on SC130 (Z180 motherboard)

SC130 is a Z180 motherboard which can run RomWBW without any additional expansion modules.

System based on SC126 (Z180 motherboard)

SC126 is a Z180 motherboard which can run RomWBW without any additional expansion modules.

System based on SC111 (Z180 module)

SC111 is a Z180 module for an extended RC2014 bus. It is designed to be used with memory module SC119.

Systems based on the RC2014 bus

The requirements to run RomWBW on the RC2014 bus or extended versions of the RC2014 bus, are:

  • A Z80 or Z180 CPU with a 512k ROM / 512k RAM board, where the memory board includes memory management hardware and the CPU only directly addresses 64k bytes. For example:

Homebrew 8-bit retro computing