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Revive a Cisco IDS into a capable OpenBSD computer!

Even though Cisco equipment is very capable, it tends to become End-of-Life before you can say “planned obsolescence”. Websites become bigger, bandwidths increase, and as a side effect of those “improvements”, routers, firewalls, and in this case, intrusion prevention systems get old quicker and quicker.
Apparently, this was also the case for the Cisco IDS-4215 Intrusion Detection Sensor that I was given a few months ago.

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Run an outdated cluster with diskless OpenBSD and cute little green boxes (part 3)

In the previous part, we set up DHCP, TFTP and RARP servers and successfully booted the OpenBSD ramdisk install kernel on old Soekris hardware over the network from a repurposed Cisco IDS. In the last part of this series, we will add NFS shares to the mix and install OpenBSD to them, making our PXE clients fully functional and then set up a minimal router and a caching DNS to provide our clients with working internet access.

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Run an outdated cluster with diskless OpenBSD and cute little green boxes (part 2)

In the first part, we became familiar with the hardware we’ll be working on and gathered the needed information. In this part, we focus on making PXE work up to the point we’re able to get to the boot loader and load a kernel.

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Run an outdated cluster with diskless OpenBSD and cute little green boxes

Does anyone remember Soekris Engineering, the company that made network hardware and somehow also audiophile equipment? The first part of the company has unfortunately closed down in April 2017, while the latter still persists today. However, we won’t be focusing on high-fidelity audio in this guide, but rather on squeezing the last bits of life out of their old products.

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The Matchbox Screamer – Part One

Recently, I’ve ran across a lot of TDA7231 chips in my workshop and figured out I’d use them for something. That something turned out to be a stereo 1.6W audio amplifier, which I named the Matchbox Screamer. Here’s the circuit diagram:
schematic
The circuit is based on the example circuit in the datasheet and is designed to operate voltage-independent. The voltage range is 1.8-15 V, with which also varies the output power. That means it can be powered from basically whatever you desire, from li-ion batteries, to USB, to 9V batteries.
I still have to etch the PCB for the thing and will post an update when I build and test it.