# Acorn Z80 Co-Processor

BeebEm emulates the Acorn Z80 Co-Processor board. The Acorn Z80 was a CP/M based system running with 64KB RAM on a Z80 processor.

You start the Acorn Z80 by selecting Acorn Z80 Co-Processor on the Hardware → Second Processor menu. If you load a CP/M system disc in drive 0, the system will then boot to an A: prompt.

BeebEm uses Jonathan Harston's v1.21 Z80 Co-Processor ROM by default. This version fixes several bugs in the Acorn v1.20 ROM (see documentation). The v1.20 ROM is included in the BeebFile folder as Z80-1.20.rom. To use this version, rename it to Z80.rom.

A CP/M Utilities disc is in the DiscIms folder which will boot the system. The Acorn Z80 originally came with 7 discs which can be download from Jon Welch's website.

These discs contain the Acorn Z80 application software including:

- CPM Utilities
- BBC Basic
- Mallard Basic
- CIS Cobol
- MemoPlan
- GraphPlan
- FilePlan
- Accountant
- Nucleus

You will also find some manuals for this software on the site as well.

The Acorn Z80 should also run most CP/M compatible software but no guarantees are given for what will and what won't work.