Logic Analyser

When I needed to look at waveforms on a digital interface recently, I used my Rigol scope as a logic analyser. It's not a mixed signal scope, but it has some features that allow it to be a 4 channel logic analyser. It can decode a parallel 4 bit bus as hex, for instance. It was right at the limit of what it can do, but as a logic analyser it was really at the bottom end of what I wanted it to do. So I looked about for logic analysers. There's a lot of the HP analysers about but they tend to need software on floppy disks and they will be decaying and get harder to find as time goes by, and they are mechanical and that is always the first thing to go.

Then I saw the Thurby Thandar (or TTi as they are now) LA4800 logic analyser.

It has it's firmware in ROM, and has 48 channels. It can go to 100MHz, but runs slower with normal pods. As an added bonus the service manual is on the internet, which makes it fixable.

I saw one on ebay and bought it, unfortunately without any pods. This isn't a massive problem as the service manual has the pod schematics, so I'm having a go at making a pod for it. Just a simple 32 channel pod, we'll see how it goes.

The analyser suffered a bit in transit and the display has a couple of odd faults on it, which is a real shame, maybe I'll find another one as a spares machine? Anyway it didn't start up when it arrived either, but it looks like it had a drop on the way here and the display connector had moved a bit, as after unplugging and replacing the display connector it works.

I'm currently routing a pod PCB...