# Master 512 Co-Processor

BeebEm emulates the Master 512 Co-Processor. The Master 512 Co-Processor has an Intel 80186 CPU, 512KB of memory and runs Digital Research DOS Plus.

To enable the Master 512 Co-Processor, select these menu options:

- Hardware → BBC Model → BBC Master 128
- Hardware → Second Processor → Master 512 Second Processor

If you want to use GEM then also enable BeebEm's AMX mouse emulation.

BeebEm is supplied with images the original disks supplied with the Master 512:

- BBCMaster512-Disc1-DosPlusBoot.adl – DR DOS Plus 1.2 boot disk
- BBCMaster512-Disc2-GemApplications.img – GEM Applications
- BBCMaster512-Disc3-GemData.img – GEM data
- BBCMaster512-Disc4-Miscellaneous.img – Miscellaneous

You can find more information about the BBC Master 512 at Yellow Pig's website and Chris's Acorns, and lots of disk images with software to use at Jon Welch's website.