The Man Whose ‘Scopes We All Wanted To Own: Walter LeCroy

July 10, 2023 by Jenny List 11 Comments

We’re sorry to say that back in May we missed the passing of Walter LeCroy, the man whose name appeared on some of the most desirable and higher-spec oscilloscopes to be found. If you’ve never used a LeCroy ‘scope then you’ll still have benefited from his work, as a pioneer of storage oscilloscopes even the more modest instruments which now grace our benches owe much to his legacy.

The linked article about his life comes from the successor to his company, and describes his early experience in scientific instrumentation and in particular in the field of high-energy physics,before the development of the first digital storage oscilloscopes. In particular it mentions the 1971 “Waveform Digitizer”,a device that used a transmission line and a series of sample-and-hold circuits to grab and digitize a sequence of readings with a single ADC. It goes on to describe the model 9400 series from the 1980s which with its successors are probably are what come to mind for many of us when thinking of a LeCroy ‘scope, the familiar big square box with integrated computer-style CRT, floppy drive, and small printer.

Here in 2023 it’s not beyond the bounds of possibility to design your own digital oscilloscope simply by pairing a fast microcontroller with an appropriately expensive ADC chip. To look back at the effort required to produce one with a high bandwidth using 16-bit microcomputer parts and 1980s silicon is to be reminded that we stand upon the shoulders of giants.

Thanks [Daniel Valuch] for the tip.

Jenny’s Daily Drivers: Slackware 15

July 10, 2023 by Jenny List 53 Comments

As a recent emigre from the Ubuntu Linux distribution to Manjaro, I’ve had the chance to survey the field as I chose a new distro, and I realised that there’s a whole world of operating systems out there that we all know about, but which few of us really know. Hence this is the start of what I hope will be a long-running series, in which I try different operating systems in my everyday life as a Hackaday writer, to find out about them and then to see whether they can deliver on the promise of giving me a stable platform on which to earn a living.

For that they need an internet connection and a web browser up-to-date enough to author Hackaday stories, as well as a decent graphics package. In addition to using the OS every day though, I’ll also be taking a look at what makes it different from all the others, what its direction and history is, and how user-friendly it is as an experience. Historical systems such as CP/M are probably out of the question as are extremely esoteric ones such as the famous TempleOS, but this still leaves plenty of choice for an operating system tourist. Join me then, as I try all the operating systems.

A Distro From The 1990s, Today

A desktop mini tower PC with monitor showing the Slackware boot screen — The Hackaday test PC gets its first outing.

When deciding where to start on this road, there was an obvious choice. Slackware was the first Linux-based distribution I tried back in 1995, I’m not sure which version it was , but it came to me via a magazine coverdisk. It was by no means the first OS that captured my attention as I’d been an Amiga user for quite a few years at that point, but at the moment I can’t start with AmigaOS as I don’t have nay up-to-date Amiga-compatible hardware.

July 2023 also marks the 30th anniversary for the distro making it the oldest one still in active development, so this seems the perfect month to start this series with the descendant of my first Linux distro. Slackware 15 comes as a 3.8 GB ISO file download for 64-bit computers, and my target for the distro was an old desktop PC with an AMD processor and a big-enough spinning rust hard disk which had been a high-end gaming system a little over ten years ago. Not the powerhouse it once was, but it cost me nothing and it’s adequate for my needs. Installed on a USB Flash drive the Slackware installer booted, and I was ready to go. Continue reading “Jenny’s Daily Drivers: Slackware 15” →

The ThinkPad You All Wish You Had, With A Brain That’s Not Ancient

July 10, 2023 by Jenny List 26 Comments

An IBM (or, later, Lenovo) ThinkPad is a popular choice in our community. They’re prized for their rugged design, longevity, and good software support. Over the many years that the line has been available, there have been a few models which have captured the attention more than others, and among those, probably the most sought-after is the ThinkPad 701c. It would be an unremarkable mid-1990s 486 laptop were it not for the party piece of that flip-out butterfly keyboard (see video, below). [Karl Buchka] has one that’s profoundly dead, and rather than use it as a novelty paperweight, he’s giving it a new lease of life with a Framework motherboard.

This is very much a work in progress, so there will be plenty more to come, but so far, he’s taken the display panel from an iPad and made it work with the Framework board, and designed an entirely new lower case for the Thinkpad. This will hold the Framework board with its USB-C ports at the edge, so in the place of its USB-based expansion modules, he’s made a custom external port replicator. Meanwhile, a Teensy handles that unique keyboard. We’re told that the design files will all eventually be put online should anyone else want to try.

We’d normally be slightly upset were someone to butcher something as unusual as a 701c, however, in thic ase we can see that it turns a broken computer into one that should see quite a bit of use. We can’t help envying him this project.

Understandably not many 701c owners have dived inside their machines, but we have previously brought you a contemporary processor upgrade. If you’ve never seen the 701c’s keyboard — or you just want to see it again — here you go:

Thanks [Ł. Juszczak] for the tip.

The Other Way To Fight Software Rental

July 8, 2023 by Jenny List 208 Comments

It’s been a distressing trend over the last decade, that of taking commercial software from a paid-for licence model and moving into the cloud and onto a rental model. In out line, we’ve seen this with CAD packages and notably with EAGLE PCB CAD, but it’s hit other sectors in exactly the same way. The art and design communities, in particular, are feeling the pinch from Adobe Suite going towards a rental model, and now the artist and perennial thorn in the side of anyone who seeks to own a colour, [Stuart Semple] is doing something about it. He’s launching a competing suite called provocatively, Abode, which will follow an affordable paid-for licence model. It’s a development that raises interesting questions for the open source community, so it’s definitely worth a second look from that perspective.

Taking on software rental can only be a good thing, and we hope that the new package gains a foothold for that reason. But since we’re sure that there will be open-source enthusiasts asking the question: why are the established open-source equivalents such as GIMP and Inkscape not the obvious alternatives to the Adobe suite? In there may be some uncomfortable moments of soul searching for the software libre world around usability and interfaces.

Whatever your take on open source versus paid software, it’s extremely encouraging to have somebody mount a high-profile challenge to the software rental model. We hope that Abode makes it to market and that it succeeds in making the graphics software market a little more open. Meanwhile, we’ve mentioned [Stuart Semple] before for his colour activism over the blackest of blacks, and for previously taking on Adobe over Pantone pricing.

A Shutter Speed Tester With Frickin’ Lasers!

July 7, 2023 by Jenny List 12 Comments

Buying old cameras is one of the best ways yet found to part a geek from their money, but if you don’t mind finding a few duds along the way it’s still possible to pick up something nice without paying the excessive scene tax of an Etsy seller or an online store. The trouble is, in the many decades during which your purchase went from being pride and joy to forgotten in a drawer to lying on the shelf of a thrift store, its performance may have degraded a little. Does the shutter still operate as it should? How long is a split second anyway? You need a shutter speed tester, and luckily for us, [Stuart Brown] has one.

There are no sharks involved in this build, but it does rely on laser diodes as a light source. There are three of them as well as three sensors, packaged photodiodes with a Schmidt trigger. These feed an Arduino which is hooked up to a TFT display, and the software measures how long each diode receives the light. We’re told it can also measure the raise time on curtain shutters, another important metric.

There’s little in the way of usage examples, but we’re guessing it requires positioning the camera between lasers and photodiodes. We’re curious as to how such an instrument would perform on a camera with a fixed lens, or whether it’s only suitable for those with access to the shutter itself. If this subject interests you, it’s not the first shutter speed tester we’ve shown you.

Header image: Runner1616, CC BY-SA 4.0.

It’s A Humble ‘Scope, But It Changed Our World

July 6, 2023 by Jenny List 46 Comments

A few years ago on a long flight across the North Atlantic, the perfect choice for a good read was iWoz, the autobiographical account of [Steve Wozniak]’s life. In it, he described his work replicating the wildly successful Pong video game and then that of designing the 8-bit Apple computers. A memorable passage involves his development of the Apple II’s color generation circuitry, which exploited some of the artifacts of the NTSC color system to produce a color display in a far simpler manner than might be expected. Now anyone seeking a connection with both Pong and the Apple II can have one of their very own if they have enough money because [Al Alcorn]’s Tektronix 465 oscilloscope is for sale. He’s the designer of the original Pong and used the instrument in its genesis, and then a few years later, he lent it to [Woz] for his work on the Apple II.

This may be the first time Hackaday has featured something from the catalogue of a rare book specialist, but if we’re being honest, for $135,000, it’s a little beyond the reach of a Hackaday scribe. The Tek 465 was a 100 MHz dual-trace model manufactured from 1972 to the early 1980s and, in its day, would have been a very desirable instrument indeed. This one is in pretty good condition with accompanying leads and manual and comes with a letter of authenticity and a hand-written annotation from [Al] himself on its underside. It can be seen up close in the video below the break.

As a ‘scope it’s an instrument many of us would still find useful today, but as the instrument which set in motion not one but two of the seminal moments of our craft, its historical importance can’t be overstated. We hope it will find its way into a museum or similar place where the story of those two developments can be told and that [Al] profits handsomely from its sale.

Continue reading “It’s A Humble ‘Scope, But It Changed Our World” →

System Essentially Contradicting American Methods

July 5, 2023 by Jenny List 36 Comments

Today, acronyms such as PAL and initialisms such as NTSC are used as a lazy shorthand for 625 and 525-line video signals, but back in the days of analogue TV broadcasting they were much more than that, indeed much more than simply colour encoding schemes. They became political statements of technological prowess as nations vied with each other to demonstrate that they could provide their citizens with something essentially home-grown. In France, there was the daddy of all televisual symbols of national pride, as their SECAM system was like nothing else. [Matt’s TV Barn] took a deep dive into video standards to find out about it with an impressive rack of test pattern generation equipment.

At its simplest, a video signal consists of the black-and-while, or luminance, information to make a monochrome picture, along with a set of line and frame sync pulses. It becomes a composite video signal with the addition of a colour subcarrier at a frequency carefully selected to fall between harmonics of the line frequency and modulated in some form with the colour, or chrominance, information. In this instance, PAL is a natural progression from NTSC, having a colour subcarrier that’s amplitude modulated and with some nifty tricks using a delay line to cancel out colour shifting due to phase errors.

SECAM has the same line and frame frequency as PAL, but its colour subcarrier is frequency modulated instead of amplitude modulated. It completely avoids the NTSC and PAL phase errors by not being susceptible to them, at the cost of a more complex decoder in which the previous line’s colour information must be stored in a delay line to complete the decoding process. Any video processing equipment must also, by necessity, be more complex, something that provided the genesis of the SCART audiovisual connector standard as manufacturers opted for RGB interconnects instead. It’s even more unexpected at the transmission end, for unlike PAL or NTSC, the colour subcarrier is never absent, and to make things more French, it inverted the video modulation found in competing standards.

The video below takes us deep into the system and is well worth a watch. Meanwhile, if you fancy a further wallow in Gallic technology, peer inside a Minitel terminal.

Continue reading “System Essentially Contradicting American Methods” →