The eZ80 for RCBus/RC2014 is a module designed for the RCBus and RC2014 backplanes.
Its designed as a 'compatible upgrade' to the stock Z80 CPU. The eZ80 is a CPU that was first released by Zilog about 20 years ago, and still available from the manufacturer today.
If you want to read through the full development history of this project, have a look at my hackaday project page: https://hackaday.io/project/196330-ez80-cpu-for-rc2014-and-other-backplanes
also mirrored at https://dinoboards.github.io/ez80-for-rc2014-backplanes/
The eZ80 CPU is an enhanced version of the original Z80, largely maintaining compatibility with its predecessor while offering significant improvements. It can directly address up to 16MB of memory and achieves far greater performance per clock cycle due to increased instruction efficiency and pipelining. Additionally, it integrates various on-chip peripherals such as timers, UART, SPI, I2C, and GPIOs, reducing the need for external hardware components.
While the eZ80 might appear slow and limited by today's standards, it represents, I think, an interesting evolution from the original 1970s Z80 to the modern day embedded microcontrollers.
This repository includes:
- firmware: Firmware for the on-chip flash ROM of the eZ80
- programmer: Code and instructions for using a Raspberry Pi Pico module to flash the firmware (an alternative to the Zilog eZ80 Acclaim USB Smart Cable)
- hardware: PLD/JED code for the ATF16V8 PLD required for the eZ80 RCBus Interface Module
- apps: A collection of CP/M applications to support and explore the eZ80
This eZ80 module needs to be installed into a RC2014 or RCBus compatible backplane, and paired with a compatible ROM/RAM module running RomWBW (eg: the RC2014 Stock 512K ROM/RAM module).
The RomWBW image needs to be assembled with the EZ80 STD target (see RomWBW build instructions).
See RomWBW
The eZ80 CPU module features a 6-pin header for connecting the Zilog programmer's IDC connector. It is important to note that this header is not keyed, which means the connector can be attached in the incorrect orientation.
The silk screen on the PCB indicates the correct orientation for the IDC connector.
Refer to the following images for the correct installation orientation.
Incorrect orientation may result in damage to the CPU and or the programmer. I have yet to do it to find out what happens!
