The aim of this design is to make entry into the Z50Bus universe easier and more reliable, by using fewer components, less soldering, and fewer configuration jumpers. 

This Z50Bus card can work in a modest way as a single board computer (SBC), yet can easily be expanded to run CP/M and more.

Features

• Z80 running at 7.3728 MHz
• 128k bytes RAM (second 64k not easy to use, so best consider it to be 64k usable)
• 32k bytes ROM, which can be paged out to give 64k bytes of RAM
• Simple bit-bang serial port to get you started
• LiNC Z50Bus header plug
• Voltage supervisor and reset device
• LED for power and status indication
• Runs the Small Computer Monitor, with ROM BASIC and the CP/M loader included
• Comprehensive documentation

The idea is that you can build the board and use it in a modest way before needing to build a backplane and additional cards.

There should be a good chance of such a simple circuit working first time. If it doesn't work then it is a relatively simple circuit to troubleshoot. The onboard LED can flash results of the self-test, so a serial port or RAM problem will not look like a dead processor.

Once you have the processor card working you can expand the system with a backplane, a proper hardware serial card, such as SC125 (coming soon), and a Compact Flash board (coming soon). This will allow you to run CP/M.

The Kit

The kit contains everything you need to build the card, except solder, tools and cleaning materials. To use the completed card you require a USB to serial adapter (5-volt power and 5-volt signals), a computer, and a terminal program, such as Tera Term.

If you have any doubts about sourcing a suitable USB to serial adapter, you might like to include this option with your kit.

Documentation

This product has a user guide and an assembly guide. The Small Computer Monitor has a user guide and a detailed tutorial. These documents can be found at www.scc.me.uk or by following the documentation link below.

Related items

• SC118 - Printed circuit board on its own
• SC128 - Modular backplane
• Components, spares, and accessories

Notes

• This product is supplied as a kit of parts that require assembly.
• It is your responsibility to pay any import duty or taxes charged by your home country.
• This design is made with the permission of LiNC (designers of the Z50Bus).
• This product is designed for hobby use and is not suitable for industrial, commercial or safety-critical applications.