The ZX Spectrum Logic Analyzer

We know [Happy Little Diodes] frequently works with logic analyzer projects. His recent wireless logic analyzer for the ZX Spectrum is one of the oddest ones we’ve seen in a while. The heart of the system is an RP2040, and there are two boards. One board interfaces with the computer, and another hosts the controller.

The logic analyzer core is powered by a common open-source analyzer from [Eldrgusman]. This is one of the nice things about open source tools. Most people probably don’t need a logic analyzer that plugs directly into a ZX Spectrum. But if you do, it is fairly simple to repurpose a more generic piece of code and rework the hardware, if necessary.

You used to pay top dollar to get logic analyzers that “knew” about common CPUs and could capture their bus cycles, show execution, and disassemble the running code. But using a technique like this, you could easily decode any processor, even one you’ve designed yourself. All you need to do is invest the time to build it, if no one else has done it yet.

[Happy Little Diodes] is a big fan of the [Eldrgusman] design. What we would have given for a logic analyzer like this forty years ago.