Retrotechtacular: Powerline Sagging And Stringing In The 1950s

August 17, 2024 by 14 Comments

While high-voltage transmission lines are probably the most visible components of the electrical grid, they’re certainly among the least appreciated. They go largely unnoticed by the general public — quick, name the power line closest to you right now — at least until a new one is proposed, causing the NIMBYs and BANANAs to come out in force. To add insult to injury, those who do notice the megastructures that make modern life possible rarely take a moment to appreciate the engineering that goes into stringing up hundreds of miles of cable and making sure it stays up.

Not so the Bonneville Power Administration, the New Deal-era federal agency formed to exploit the hydroelectric abundance of the Pacific Northwest of the United States, which produced this 1950 gem detailing the stringing and sagging of power lines. Unsurprisingly, the many projects needed to wire together the often remote dams to the widely distributed population centers in an area that was only just starting to see growth began in the BPA’s offices, where teams of engineers hunched over desks worked out the best routes. Paper, pencil, and slide rules were the tools of the trade, along with an interesting gadget called a conductor sag template, a hardware implementation of the catenary equation that allowed the “sagger” to determine the height of each tower. The conductors, either steel-cored aluminum or pure copper, were also meticulously selected based on tensile strength, expected wind and ice loading, and the electrical load the line was expected to carry.

Once the engineers had their say, the hard work of physically stringing the wires began out in the field. One suspects that the work today is much the same as it was almost eighty years ago, save for much more stringent health and safety regulations. The prowess needed to transfer the wires from lifting sheaves to the insulators is something to behold, and the courage required to work from ladders hanging from wires at certain death heights is something to behold. But to our mind, the real heroes were the logistics fellows, who determined how much wire was needed for each span and exactly where to stage the reels. It’s worth sparing a moment’s thought for the daring photographer who captured all this action, likely with little more than a leather belt and hemp rope for safety.

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Building The Unreleased Lemmings Arcade Cabinet From 1991

July 29, 2024 by 7 Comments

Back in the early 90s the world was almost graced with an arcade version of Lemmings, but after a few board revisions it was abandoned in 1991. Now the folk over at UK-based [RMC – The Cave] on YouTube have managed to not only get their mitts on a nearly finished prototype board, but have also designed and built a period-appropriate cabinet to go with it. This involved looking at a range of arcade cabinets created by Data East and picking a design that would allow both for the two-player mode of the game, and fit the overall style.

The finished Lemmings arcade cabinet. (Credit: RMC – The Cave, YouTube)

Arcade cabinets came in a wide range of cabinet styles and control layouts, largely defined by the game’s requirements, but sometimes with flourishes to distinguish the cabinet from the hundred others in the same arcade.

In this particular case the typical zig-zag (Z-back) style was found to be a good fit as on the Data East Night Slashers 1993-era cabinet, which then mostly left the controls (with two trackballs) and cabinet art to figure out. Fortunately there is plenty of inspiration when it comes to Lemmings art, leading to the finished cabinet with the original mainboard, the JAMMA wiring harness with MultiPi JAMMA controller, a 19″ CRT monitor and other components including the 3D printed controls panel.

With more and more new arcades popping up in the US and elsewhere, perhaps we’ll see these Lemmings arcade cabinets appear there too, especially since the ROMs on the prototype board were dumped for convenient MAME-ing.

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AMD Returns To 1996 With Zen 5’s Two-Block Ahead Branch Predictor

July 28, 2024 by 14 Comments

An interesting finding in fields like computer science is that much of what is advertised as new and innovative was actually pilfered from old research papers submitted to ACM and others. Which is not to say that this is necessarily a bad thing, as many of such ideas were not practical at the time. Case in point the new branch predictor in AMD’s Zen 5 CPU architecture, whose two-block ahead design is based on an idea coined a few decades ago. The details are laid out by [George Cozma] and [Camacho] in a recent article, which follows on a recent interview that [George] did with AMD’s [Mike Clark].

The 1996 ACM paper by [André Seznec] and colleagues titled “Multiple-block ahead branch predictors” is a good start before diving into [George]’s article, as it will help to make sense of many of the details. The reason for improving the branch prediction in CPUs is fairly self-evident, as today’s heavily pipelined, superscalar CPUs rely heavily on branch prediction and speculative execution to get around the glacial speeds of system memory once past the CPU’s speediest caches. While predicting the next instruction block after a branch is commonly done already, this two-block ahead approach as suggested also predicts the next instruction block after the first predicted one.

Perhaps unsurprisingly, this multi-block ahead branch predictor by itself isn’t the hard part, but making it all fit in the hardware is. As described in the paper by [Seznec] et al., the relevant components are now dual-ported, allowing for three prediction windows. Theoretically this should result in a significant boost in IPC and could mean that more CPU manufacturers will be looking at adding such multi-block branch prediction to their designs. We will just have to see how Zen 5 works once released into the wild.

Seiko Had A Smartwatch In 1984

July 16, 2024 by 32 Comments

You might think of the smartwatch era as beginning with Apple, relatively recently. Or, you might think back to those fancy Timex models with the datalink thing going on in the 1990s. Seiko can beat them all, though, with its UC-2000 smartwatch that debuted all the way back in 1984.

The UC2200 was the bigger docking station of the two.

The UC-2000 very much looks cutting edge for its era, and absolutely ancient today. It featured a 4-bit CPU, 2 kilobytes of RAM, and 6 kilobytes of ROM. Display was via a simple 10×4 character LCD in a rectangular form factor, with four buttons along the bottom. Branded as a “personal information processor,” it was intended for use with the UC-2100 dock. This added a full physical QWERTY keyboard that interacted with the UC-2000 when the two were combined together. Alternatively, you could go for the UC-2200, which not only had a keyboard but also a thermal printer to boot. Oh, and ROM packs for Microsoft Basic, games, or an English-to-Japanese translator.

What could you do on this thing? Well, it had basic watch functions, so it told the time, acted as a stop watch, and an alarm, of course. But you could also use it to store two memos of up to 1000 characters each, schedule appointments, and do basic calculations.

The one thing this smartwatch was missing? Connectivity. It couldn’t get on the Internet, nor could it snatch data from the ether via radio or any other method. By today’s measures, it wouldn’t qualify as much of a smartwatch at all. Moreso a personal organizer that fit on the wrist. Still, for its day, this thing really was a whole computer that fit on your wrist.

Would you believe we’ve seen the UC-2000 before? In fact, we’ve even seen it hacked to play Tetris! Video of that wonderful feat after the break.
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The NSA Is Defeated By A 1950s Tape Recorder. Can You Help Them?

July 13, 2024 by 56 Comments

One of the towering figures in the evolution of computer science was Grace Hopper, an American mathematician, academic, and Naval reservist, whose work gave us the first programming languages, compilers, and much more. Sadly she passed away in 1992, so her wisdom hasn’t directly informed the Internet Age in the manner of some of her surviving contemporaries.

During her life she gave many lectures though, and as [Michael Ravnitzky] discovered, one of them was recorded on video tape and resides in the archives of America’s National Security Agency. With the title “Future Possibilities: Data, Hardware, Software, and People”, it was the subject of a Freedom Of Information request. This in turn was denied, on the grounds that “Without being able to view the tapes, NSA has no way to verify their responsiveness”. In short, the recording lies on Ampex 1″ reel-to-reel video tape, which the NSA claims no longer to be able to read.

It’s fairly obvious from that response that the agency has no desire to oblige, and we’d be very surprised to find that they keep a working Ampex video system to hand on the off-chance that a passing researcher might ask for an archive tape. But at the same time it’s also obvious that a lecture from Rear Admiral Hopper is an artifact of international importance that should be preserved and available for study. It’s an interesting thought exercise to guess how many phone calls Hackaday would have to make to secure access to a working Ampex video recorder, and since we think for us that number would be surprisingly low it’s likely the NSA know exactly who to call if they needed that tape viewed in a hurry. We don’t have influence over secretive government agencies, but if we did we’d be calling shame on them at this point.

If you’re curious about Grace Hopper, we’ve talked about her work here in the past.

Thanks [F4GRX] for the tip.

Ampex image: Telecineguy., Public domain.

The Workstation You Wanted In 1990, In Your Pocket

July 3, 2024 by 61 Comments

Years ago there was a sharp divide in desktop computing between the mundane PC-type machines, and the so-called workstations which were the UNIX powerhouses of the day. A lot of familiar names produced these high-end systems, including the king of the minicomputer world, DEC. The late-80s version of their DECstation line had a MIPS processor, and ran ULTRIX and DECWindows, their versions of UNIX and X respectively. When we used one back in the day it was a very high-end machine, but now as [rscott2049] shows us, it can be emulated on an RP2040 microcontroller.

On the business card sized board is an RP2040, 32 MB of PSRAM, an Ethernet interface, and a VGA socket. The keyboard and mouse are USB. It drives a monochrome screen at 1024 x 864 pixels, which would have been quite something over three decades ago.

It’s difficult to communicate how powerful a machine like this felt back in the very early 1990s, when by today’s standards it seems laughably low-spec. It’s worth remembering though that the software of the day was much less demanding and lacking in bloat. We’d be interested to see whether this could be used as an X server to display a more up-to-date application on another machine, for at least an illusion of a modern web browser loading Hackaday on DECWindows.

Full details of the project can be found in its GitHub repository.

Everyone Needs A 1950s Signal Generator In Their Life

July 2, 2024 by 8 Comments

At Hackaday, we comb the world of tech in search of good things to bring you. Today’s search brought up something very familiar, [Jazzy Jane] has an Advance E1 tube signal generator, the same model as the unit on the shelf above where this is being written. It’s new to her, so she’s giving it a teardown and fixing any safety issues before powering it on.

For a 70+ year old unit, the quality of these instruments was such that they remain useful and reliable to this day. Unsurprisingly a few things need looking at, such as an aged mains lead and a pair of filter caps in the power supply which haven’t aged well. These parts failed on the E1 here too, and while she’s taking the time to order appropriate replacements we have to admit to being cheapskates and robbing parts with an appropriate working voltage for ours from a nearby PC power supply.

Where this one becomes rather interesting is in an extra switch and socket. It’s a wafer switch with a load of capacitors, and the best guess is it provides some adjustability for the inbuilt audio oscillator which had a fixed frequency on stock models. This is part one of a series though, so we’re looking forward to finding out its purpose in the next installment. Take a look at the video below the break, and if that’s not enough, we seem to have had more than one piece of vintage British test equipment here of late.

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