SC130 is an easy to build, low cost, Z180 RomWBW Computer. The kit comes complete with serial adapter, USB cable, and a micro SD card adapter. Just add a micro SD card for storage and a computer running terminal software, and you have a complete system able to run CP/M software.

SC128, a modular backplane for the Z50Bus, is now available. Details here.

SC129 is a digital I/O module designed for the RC2014 bus.

In part 1 of this series we took a very quick tour through the whole process of designing a product. In part 2 and part 3 we designed the electronics for a digital I/O module. We will now design the circuit board.

In part 2 of this series we started designing the electronics for our digital I/O interface. In this part we will complete the schematic.

In part 1 of this series we took a very quick tour through the whole process of designing a product. We will now begin a much more detailed look at designing a Digital Input/Output interface for a Z80 computer.

Someone recently asked me a few questions about design, which got me thinking about writing a series of posts for this website.

I hope to encourage anyone who has considered designing their own retro computer add-on, or indeed a whole system, to have a go. Getting that first professional looking PCB in the post is very rewarding and is relatively cheap.

SC126 Z180 SBC / Motherboard with RomWBW firmware has now been released.