Many of us used “big iron” back in the day. Computers like the IBM S/360 or 3090 are hard to find, transport, and operate, so you don’t see many retrocomputer enthusiasts with an S/370 in their garages. We’ve known for a while that the Hercules emulators would let you run virtual copies of these old mainframes, but every time we’ve looked at setting any up, it winds up being more work than we wanted to spend. Enter [Ernie] of [ErnieTech’s Little Mainframes]. He’s started a channel to show you how to “build” your own mainframe — emulated, of course.
One problem with the mainframe environment is that there are a bunch of operating system-like things like MVS, VM/CMS, and TSO. There were even custom systems like MUSIC/SP, which he shows in the video below.
Different cultures have their own conventions for naming locations, for example in the United Kingdom there are plenty of places named for monarchs, while in many other countries there are not. An aspect of this fascinated [Ben Ashforth], who decided to find all the streets in Europe named after auspicious dates, and then visit enough to make a calendar. He gave a lightning talk about it at last year’s EMF Camp, which we’ve embedded below.
Starting with an aborted attempt to query Google Maps, he then moved on to the OpenStreetMap database. From there he was able to construct a list of date-related street name across the whole of Europe, and reveal a few surprising things about their distribution. He came up with a routing algorithm to devise the best progression in which to see them, and with a few tweaks to account for roads whose names had changed, arrived at an epic-but-efficient traversal of the continent. The result is a full year’s calendar of street names, which you can download from his website.
Being used to significant Interrail travel where this is written, we approve of an algorithmically generated Euro trip. We’re indebted to [Barney Livingstone] for the tip, and we agree with him that 150 slides in a 5 minute talk is impressive indeed.
[Stephen Woodward] is familiar with digital potentiometers but is also familiar with their limitations. That spurred him to create the PWMPot which performs a similar function, but with better features than a traditional digital pot. Of course, he admits that this design has some limitations of its own, so — as usual — you have to make your design choices according to what’s important to you.
Perhaps the biggest limitation is that the PWMPot isn’t useful at even moderately high frequencies. The circuit works by driving two CMOS switches into an RC circuit. The switches’ inverted phase tends to cancel out any ripple in the signal.
If you’ve owned a CD player or other piece of consumer digital audio gear manufactured since the 1980s, the chances are it has a TOSLINK port on the back. This is a fairly simple interface that sends I2S digital audio data down a short length of optical fibre, and it’s designed to run between something like a CD player and an external DAC. It’s ancient technology in optical fibre terms, with a lowish data rate and plastic fibre, but consider for a minute whether it could be adapted for modern ultra-high-speed conenctions. It’s what [Ben Cartwright-Cox] has done, and he delivered a talk about it at the recent 38C3 event in Germany.
if you’ve cast you eye over any fibre networking equipment recently, you’ll be familiar with SFP ports. These are a standard for plug-in fibre terminators, and they can be had in a wide variety of configurations for different speeds, topographies, and wavelengths. They’re often surprisingly simple inside, so he wondered if he could use them to carry TOSLINK instead of a more conventional network. And it worked, with the simple expedient of driving an SFP module with an LVDS driver to make a differential signal. There follows a series of experiments calling in favours from friends with data centre space in various locations around London, finally ending up with a 140 km round trip for CD-quality audio.
It’s an interesting experiment, but perhaps the most value here is in what it reveals to us about the way optical networking systems work. Most of us don’t spend our days in data centres, so that’s an interesting technology to learn about. The video of the talk itself is below the break.
This week, Jonathan Bennett and Randal chat with Matija Šuklje about Open Source and the Law! How do Open Source projects handle liability, what should a Contributor License Agreement (CLA) look like, and where can an individual or project turn for legal help?
There are many AI models out there that you can play with from companies like OpenAI, Google, and a host of others. But when you use them, you get the experience they want, and you run it on their computer. There are a variety of reasons you might not like this. You may not want your data or ideas sent through someone else’s computer. Maybe you want to tune and tweak in ways they aren’t going to let you.
There are many more or less open models, but setting up to run them can be quite a chore and — unless you are very patient — require a substantial-sized video card to use as a vector processor. There’s very little help for the last problem. You can farm out processing, but then you might as well use a hosted chatbot. But there are some very easy ways to load and run many AI models on Windows, Linux, or a Mac. One of the easiest we’ve found is Msty. The program is free for personal use and claims to be private, although if you are really paranoid, you’ll want to verify that yourself.
What is Msty?
Talkin’ about Hackaday!
Msty is a desktop application that lets you do several things. First, it can let you chat with an AI engine either locally or remotely. It knows about many popular options and can take your keys for paid services. For local options, it can download, install, and run the engines of your choice.
For services or engines that it doesn’t know about, you can do your own setup, which ranges from easy to moderately difficult, depending on what you are trying to do.
Of course, if you have a local model or even most remote ones, you can use Python or some basic interface (e.g., with ollama; there are plenty of examples). However, Msty lets you have a much richer experience. You can attach files, for example. You can export the results and look back at previous chats. If you don’t want them remembered, you can chat in “vapor” mode or delete them later.
Each chat lives in a folder, which can have helpful prompts to kick off the chat. So, a folder might say, “You are an 8th grade math teacher…” or whatever other instructions you want to load before engaging in chat.
You probably get a few of these things each week in the mail. And some of them actually do a good job of obscuring the contents inside, even if you hold the envelope up to the light. But have you ever taken the time to appreciate the beauty of security envelope patterns? Yeah, I didn’t think so.
The really interesting thing is just how many different patterns are out there when a dozen or so would probably cover it. But there are so, so many patterns in the world. In my experience, many utilities and higher-end companies create their own security patterns for mailing out statements and the like, so that right there adds up to some unknown abundance.
So, what did people do before security envelopes? When exactly did they come along? And how many patterns are out there? Let’s take a look beneath the flap.
