G4 IMac Gets An M1 Heart Transplant

March 8, 2022 by 7 Comments

The second-generation iMac was a big departure from the original brightly-colored release. The chunky CRT aesthetic was dead, replaced with a sleek design featuring a slim LCD monitor on a floating arm. [Connor55] recently laid his hands on such a machine, and decided it needed a transplant of some modern M1 hardware.

There’s a lot going on in there.

The machine, as it came into his possession, lacked WiFi, and had a disc drive struggling to open its own tray, so it made a good candidate for hacking. Out came the original motherboard and drives, leaving room for a motherboard from a Mac Mini to be substituted in, with the powerful new M1 system-on-chip onboard.

First up, the screen had to be converted to use DVI input, with a guide from [Dremel Junkie] helping out with that. The Mac Mini motherboard was then prepped to install in the iMac’s dome-shaped housing; notably, the entire board is smaller than the stock iMac G4’s hard drive. It still took plenty of cramming, with a multitude of adapters finagled and massaged to fit inside the original housing.

It’s a very completionist build; even features like the original power button and optical drive still work. It took some fiddling, but the display and backlight operate properly as per the original functionality, too.

Apple’s tasteful industrial design has always proved popular with modders. We’ve seen similar builds before over the years, from Intel NUCs stuffed into G4 iMacs to classic Macs outfitted with iPad hardware. It’s always satisfying to see vintage hardware given a new lease of life with modern grunt!

Extreme Espresso, Part 2: An Inductive Water Level Sensor

March 8, 2022 by 27 Comments

[Mark Smith] must really, really like his coffee, at least judging by how much effort he’s put into tricking out his espresso machine.

This inductive water tank sensor is part of a series of innovations [Mark] has added to his high-end Rancilio Silvia machine — we assume there are those that would quibble with that characterization, but 800 bucks is a lot to spend for a coffee maker in our books. We recently featured a host of mods he made to the machine as part of the “Espresso Connect” project, which includes a cool Nixie tube bar graph to indicate the water level in the machine. That display is driven by this sensor, the details of which [Mark] has now shared. The sensor straddles the wall of the 1.7-liter water tank, so no penetrations are needed. Inside the tanks is a track that guides a copper and PETG float that’s sealed with food-safe epoxy resin.

Directly adjacent to the float track on the outside of the tank is a long PCB with a couple of long, sinuous traces. These connect to an LX3302A inductive sensor IC, which reads the position of the copper slug inside the float. That simplifies the process greatly; [Mark] goes into great detail about the design and calibration of the sensor board, as well as hooking it into the Raspberry Pi Zero that lies at the heart of “Espresso Connect’. Altogether, the mods make for a precisely measured dose of espresso, as seen in the video below.

We’d say this was maybe a bit far to go for the perfect cup of coffee, but we sure respect the effort. And we think this inductive sensor method has a lot of non-caffeinated applications that probably bear exploration.

Continue reading “Extreme Espresso, Part 2: An Inductive Water Level Sensor” →

The Light Guide Hiding In Your Extrusion

March 8, 2022 by 23 Comments

There should be a line of jokes that start “A physicist and an engineer walk into a bar…”. In my case I’m an engineer and my housemate is a physicist, so random conversations sometimes take interesting turns. Take the other day for example, as one does when talking she picked up a piece of aluminium extrusion that was sitting on our coffee table and turned it over in her hands. It has a hole down its centre and it’s natural to peer down it, at which point her attention was caught by the appearance of a series of concentric rings of light. Our conversation turned to the mechanism which might be causing this, and along the way took us into cameras, waveguides, and optical fibres.

The light reaching us after traveling along a straight narrow tube should at a cursory glance be traveling in a straight line, and indeed when I point the extrusion out of my window and look down it I can see a small segment of the tree in the distance I’ve pointed it at. It didn’t take us long to conclude that the concentric rings were successive reflections of the light coming into the end hole from off-centre angles.

In effect, the extrusion is a pinhole camera in which the image is projected onto the inside of a cylinder stretching away from the pinhole rather than onto a flat piece of film, and we were seeing the successive reflections of the resulting distorted image as they bounced to and fro down the tube towards us. It’s likely the imperfect mirror formed by the aluminium wall allowed us to see each image, as light was being diffused in our direction. Adding a piece of tape with a small pinhole at the end accentuated this effect, with the circles becoming much more sharply defined as the projected image became less blurry. Continue reading “The Light Guide Hiding In Your Extrusion” →

History Of Digital Equipment Corp And Bonus PDP-11 Replica Build

March 8, 2022 by 58 Comments

[RetroBytes] takes us on a whirlwind tour of the history of the Digital Equipment Corporation (DEC), its founder Ken Olsen, and during intermission builds up a working replica of the PDP-11 from a kit. DEC was a major player in the early computer industry, cranking out a number of models that were both industrial workhorses and used in computer laboratories to develop many of the operating systems and tools whose descendants we still use today. On top of that, DEC’s innovative, employee-friendly, and lightweight company structure was generally well-liked by its employees and a welcomed departure from the typical behemoths of the day.

This video takes us from the beginnings of DEC and its roots in MIT up to the PIP-11 era, highlighting major architectures and events along the way such as the PDP-1, PDP-8, and PDP-11. [RetroBytes] says he has a DEC Alpha sitting on the sidelines, so there may be a few follow-up videos in the future — perhaps one on the VAX as well.

We’ve covered this particular PDP-11 replica last year, and if these replica kits are your cup of tea, check out our coverage of kit designer [Oscar Vermeulen]’s presentation. Have you ever used real PDP or VAX computers? Let us know your war stories in the comments below.

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Grid Batteries On Wheels: The Complicated Logistics Of Vehicle-Grid Integration

March 8, 2022 by 93 Comments

At its core, the concept of vehicle-grid integration (VGI) – also called Vehicle To Grid (V2G) – seems a simple one. Instead of a unidirectional charger for battery-electric vehicles (BEVs), a bidirectional charger would be used. This way, whenever the BEV is connected to such a charger, power could be withdrawn from the car’s battery for use on the local electrical grid whenever there’s demand.

Many of the complications with VGI have already been discussed, including the increased wear that this puts on a BEV’s battery, the need for an inherently mobile machine to be plugged into a charger, and the risk of needing one’s BEV and finding its battery to be nearly depleted. Here the cheerful marketing from Nissan and that from commercial initiatives such as Vehicle to Grid Britain makes it sound like it’s a no-brainer once those pesky details can be worked out.

In parallel with the world of glossy marketing leaflets, researchers have been investigating VGI as a potential option for grid-level energy storage. These studies produce a far less optimistic picture that puts the entire concept of VGI into question.

Continue reading “Grid Batteries On Wheels: The Complicated Logistics Of Vehicle-Grid Integration” →

Screenshot of a 1988 news report on the Morris Worm computer virus

Retrotechtacular: Cheesy 1980s News Report On Early Internet Virus

March 8, 2022 by 34 Comments

It was a cold autumn night in 1988. The people of Cambridge, Massachusetts lay asleep in their beds unaware of the future horror about to be unleashed from the labs of the nearby college. It was a virus, but not just any virus. This virus was a computer program whose only mission was to infect every machine it could come in contact with. Just a few deft keystrokes is all that separated law abiding citizens from the…over the top reporting in this throwback news reel posted by [Kahvowa].

Computer History Museum exhibit of the floppy disk used to distribute the Morris worm computer virus.
Computer History Museum exhibit featuring the original floppy disk used to distribute the Morris Worm computer virus.

To be fair, the concept of a computer virus certainly warranted a bit of explanation for folks in the era of Miami Vice. The only places where people would likely run into multiple computers all hooked together was a bank or a college campus. MIT was the campus in question for this news report as it served as ground zero for the Morris Worm virus.

Named after its creator, Robert Tappan Morris, the Morris Worm was one of the first programs to replicate itself via vulnerabilities in networked computer systems. Its author intended the program to be a benign method of pointing out holes, however, it ended up copying itself onto systems multiple times to the point of crashing. Removing the virus from an infected machine often took multiple days, and the total damage of the virus was estimated to be in the millions of dollars.

In an attempt to anonymize himself, Morris initially launched his worm program from a computer lab at MIT as he was studying at Cornell at the time. It didn’t work. Morris would go onto to be the first person to receive a felony conviction under the 1986 Computer Fraud and Abuse Act. After the appeals process, he received a sentence a community service and a fine. After college Morris co-founded the online web store software company Viaweb that Yahoo! would acquire in 1998 for 49 million dollars. Years later in an ironic twist, Morris would return to academia as a professor at MIT’s department of Electrical Engineering and Computer Science.

Interested in some info on viruses of a different nature? Check out this brief history on viruses from last year.
Continue reading “Retrotechtacular: Cheesy 1980s News Report On Early Internet Virus” →

Vintage Multimeter Gets An LCD Transplant

March 8, 2022 by 10 Comments

Hackers are often of the sentimental type, falling in love with the look and feel of quality old hardware. Of course, sometimes that older hardware needs a little TLC to keep it running in the modern world. [Lex] had a beautiful vintage multimeter that sadly had a broken screen, and set about a nifty repair to restore it to working condition. 

It’s a handsome thing.

The HSN Avometer DA116 is a handsome thing, controlled with two dials and featuring a clean two-tone aesthetic. Even the font on the PCB’s silkscreen is gloriously pretty (can anyone ID that?). However, the original LCD was non-functional. A direct replacement part was sadly unavailable. Instead, to rectify this, [Lex] first hunted down another segmented LCD screen that had the same segment layout.

However, the new screen had a completely different pinout to the original part. Thus, after taking some notes and figuring out what all the pins did, [Lex] whipped up an adapter board to carry the new screen. With some protoboard, some pin headers, and a bunch of point-to-point wiring, the new screen worked just fine, and [Lex] had a functioning vintage meter once again!

The story actually came to us on Twitter, where we invited discussion about the best bodge wiring jobs out there. Feel free to contribute your own stories to the conversation! If you’re in the market for more LCD hacking, be sure to check out the excellent talk [Joey Castillo] gave at the 2021 Remoticon.