# Emulated Hardware

The hardware emulated by BeebEm is that of a standard BBC Micro Model B, a Model B with IntegraB board, Model B Plus or Master 128 with a few small additions. Optional 65C02 and other types of second processor are also emulated. The emulation is accurate enough to run most software.

## Hardware common to all models

- 74689 Sound chip with 3 tone channels and one noise channel
- uPD7002 Analogue to Digital Converter
- 32K RAM
- 6845 Cathode Ray Tube Controller (CRTC)
- Acorn proprietary VIDPROC (Video Processor)
- SAA5050 Teletext generator
- System and User 6522 Versatile Interface Adaptors (VIAs)
- "IC32" Addressable latch
- Full BBC Micro keyboard
- ROMSELect Register
- 6850 Serial ACIA and Serial ULA
- 6854 Advanced Data-Link Controller (Econet)
- SCSI and SASI Hard Drives
- AMX Mouse
- Microvitec Touch Screen

## Model B Specific hardware

- Full 6502 Processor with all undocumented opcodes
- Sixteen 16K Paged ROM banks, with Sideways RAM option
- 16K OS ROM
- 8271 Floppy Disc Controller
- Keyboard links

## Model B Plus Specific hardware

- Four 16K Sideways RAM banks
- 16K B+ MOS ROM
- 20K Video Shadow RAM
- 12K Additional RAM
- Keyboard links

## Master 128 and Master ET Specific hardware

- 65C12 Processor with all undocumented opcodes filled in with corresponding undocumented 6502 opcodes
- Seven 16K Paged ROMs
- Four 16K Sideways RAM banks
- 16K MOS ROM
- 20K Video Shadow RAM
- 8K Filing System RAM
- 4K Screen Operations RAM
- 1770 Floppy Disc controller
- 146818 Real-Time Clock and CMOS RAM (50 bytes)
- ACCess CONtrol register

## 65C02 Second Processor

- 65C12 Processor
- 64K RAM
- 2K boot ROM
- TUBE ULA chip

## Master 512 Second Processor

- 80186 Processor
- 1MB RAM
- 16KB BIOS ROM
- TUBE ULA chip

## Z80 Second Processor

- Z80 Processor
- 64K RAM
- Boot ROM (8KB Torch Z80, 4KB Acorn Z80)
- TUBE ULA chip

## ARM Second Processor

- ARM3 Processor
- 4MB RAM
- 16kB Boot ROM
- TUBE ULA chip

## Sprow ARM7TDMI Second Processor

- ARM7TDMI Processor
- 512KB Flash ROM
- 64MB RAM

## Computech Integra-β

- 20KB Shadow RAM
- Sixteen 16K Paged ROM banks, with Sideways RAM option
- 12KB Private RAM
- Real-Time Clock and CMOS RAM (50 bytes)

For information on the Integra-β see the documentation in the Documents folder.