Ethernet interface: Provides two Telnet sockets.

Administration Socket on port 2300:

This allows full remote control of the board using any standard Telnet client, exactly as if commands were typed over the serial port.

User Socket on port 2301:

Provides network connectivity to programs running on the Z80. This enables legacy software - such as a BBS - to receive incoming calls. A patch for CP/M 3.0 is provided to recognize this user socket as a physical I/O device named "TELNET".

Both sockets are fully accessible to the Z80 CPU using IOS commands.

512KB supercap-backed RAM:

Can be used as a persistent, ultra-fast 352KB ramdisk under CP/M 3.0.

It also provides a nonvolatile bank for the embedded BASIC interpreter.

The remaining 128KB are used for the Z80 banked memory, just as in the original MBC2 project.

The first Z80-MBC2-V board assembled is currently running "Citadel" v2.1 under CP/M 3.0.

You can connect to the board via Telnet at address bbs.probosci.de on port 3339,

or by using this web wrapper: http://probosci.de/bbs.html

You may then Login/Register with command 'L' or read the Help with command 'H'.

The board (first version with a patch on the PSU, fixed in final version) running Citadel v2.1

Further details can be found in the project page at https://www.probosci.de/Z80mbc

Assembly note:

The glue logic and level shifters for the Ethernet and SD card interfaces are difficult to source in traditional through-hole packages. For this reason, compared to the original project, assembling this board requires a certain (small) degree of surface mount skill.

The same applies to the power supply, but this is optional - you can power the board using just the USB cable.