This is a follow-on to the original 1802 Olduino which was based on another 1970's era microprocessor. The Z80 is another processor from the same era - It was used in many early PCs including the TRS-80.
The Z80 board I'm using is made by Lee Hart. It has 32K of RAM and 32K of EPROM. It's the size of a credit card and comes with a complete front panel that lets you program it with a hex keypad and an LED readout.
I've replaced Lee's front panel board with the Olduino/Z. This has a serial interface to connect to a PC and headers that allow you to connect most arduino shields. The Olduino/Z has 4mHz SPI that supports everything from realtime clocks to ethernet boards.
Solftware for the Olduino/Z is written in C using the SDCC compiler and the Z88dk front end. I use Textpad as a programming environment and a python script to upload to the olduino over xmodem.
The Z80 is very different from the 1802 but, because most of the code is written in C, I've been able to port over most of the code without too much trouble. ecause the Z80 is faster I've been able to add features such as multiple telnet sessions along with the web server.
I have a new wifi shield that I'm looking forward to trying out in the next couple of weeks.