Why Did Early CD-ROM Drives Rely On Awkward Plastic Caddies?

December 18, 2024 by Lewin Day 45 Comments

These days, very few of us use optical media on the regular. If we do, it’s generally with a slot-loading console or car stereo, or an old-school tray-loader in a desktop or laptop. This has been the dominant way of using consumer optical media for some time.

Step back to the early CD-ROM era, though, and things were a little kookier. Back in the late 1980s and early 1990s, drives hit the market that required the use of a bulky plastic caddy to load discs. The question is—why did we apparently need caddies then, and why don’t we use them any longer?

Caddyshack

*Early CD players, like this top-loading Sony D-50, didn’t use caddies. Credit: Binarysequence, CC BY-SA 4.0*

The Compact Disc, as developed by Phillips and Sony, was first released in 1982. It quickly became a popular format for music, offering far higher fidelity than existing analog formats like vinyl and cassettes. The CD-ROM followed in 1985, offering hundreds of megabytes of storage in an era when most hard drives barely broke 30 MB. The discs used lasers to read patterns of pits and lands from a reflective aluminum surface, encased in tough polycarbonate plastic. Crucially, the discs featured robust error correction techniques so that small scratches, dust, or blemishes wouldn’t stop a disc from working.

Notably, the first audio CD player—the Sony CDP-101—was a simple tray-loading machine. Phillips’ first effort, the CD100, was a top-loader. Neither used a caddy. Nor did the first CD-ROM drives—the Phillips CM100 was not dissimilar from the CD100, and tray loaders were readily available too, like the Amdek Laserdrive-1. Continue reading “Why Did Early CD-ROM Drives Rely On Awkward Plastic Caddies?” →

Optical Tweezers Investigate Tiny Particles

April 22, 2024 by Bryan Cockfield 1 Comment

No matter how small you make a pair of tweezers, there will always be things that tweezers aren’t great at handling. Among those are various fluids, and especially aerosolized droplets, which can’t be easily picked apart and examined by a blunt tool like tweezers. For that you’ll want to reach for a specialized tool like this laser-based tool which can illuminate and manipulate tiny droplets and other particles.

[Janis]’s optical tweezers use both a 170 milliwatt laser from a DVD burner and a second, more powerful half-watt blue laser. Using these lasers a mist of fine particles, in this case glycerol, can be investigated for particle size among other physical characteristics. First, he looks for a location in a test tube where movement of the particles from convective heating the chimney effect is minimized. Once a favorable location is found, a specific particle can be trapped by the laser and will exhibit diffraction rings, or a scattering of the laser light in a specific way which can provide more information about the trapped particle.

Admittedly this is a niche tool that might not get a lot of attention outside of certain interests but for those working with proteins, individual molecules, measuring and studying cells, or, like this project, investigating colloidal particles it can be indispensable. It’s also interesting how one can be built largely from used optical drives, like this laser engraver that uses more than just the laser, or even this scanning laser microscope.

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Laser Engraver Uses All Of The DVD Drive

August 10, 2023 by Bryan Cockfield 18 Comments

For the last ten to fifteen years, optical drives have been fading out of existence. There’s little reason to have them around anymore unless you are serious about archiving data or unconvinced that streaming platforms will always be around. While there are some niche uses for them still, we’re seeing more and more get repurposed for parts and other projects like this tabletop laser engraver.

The build starts with a couple optical drives, both of which are dismantled. One of the shells is saved to use as a base for the engraver, and two support structures are made out of particle board and acrylic to hold the laser and the Y axis mechanism. Both axes are made from the carriages of the disassembled hard drives, with the X axis set into the base to move the work piece. A high-output laser module is fitted to the Y axis with a heat sink, and an Arduino and a pair of A4988 motor controllers are added to the mix to turn incoming G-code into two-dimensional movement.

We’ve actually seen a commercial laser engraver built around the same concept, but the DIY approach is certainly appealing if you’ve got some optical drives collecting dust. Otherwise you could use them to build a scanning laser microscope.

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Shake Your PCB Etching, With An Old Optical Drive

April 23, 2023 by Jenny List 28 Comments

Easy PCB fabrication in China has revolutionised electronic construction at our level, but there are still times when it makes sense to etch your own boards. It’s a messy business that can also be a slow one, but at least a project from [earldanielph] takes away one chore. It agitates the etchant solution round the board, by moving the tank backwards and forwards on the drawer of an old optical drive.

The first part of the build is simply removing all parts of the drive except the drawer mechanism and its motor. This is still, in most cases, a DC motor, so an Arduino can easily drive it with a motor control shield. It’s worth a moment to reflect on how little there is to a modern optical drive.

The Arduino receives a sketch that moves the tray backward and forward, and a piece of ply is attached to the tray. This becomes a stand for a plastic tub containing the etchant and board, and the liquid is soon swishing back and forwards over the surface. You can see the result in the video below the break. Definitely a saving over manual agitation. It’s an inventive machine, but it’s not the first PCB agitator we’ve seen.

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Adding In-Game Reset To Classic Playstations

June 1, 2021 by Bryan Cockfield 6 Comments

The first Playstation is quickly approaching three decades since its release, and while this might make some of us who were around for that event feel a little aged, the hardware inside these machines isn’t getting any younger either. Plenty of people are replacing the optical drive in the original hardware with an optical drive emulator as they begin to fail, and with that comes the option for several other modifications to the hardware like this in-game reset mod.

In-game reset is a function that allows a console to be reset via a controller button combination rather than pressing the console’s reset button directly. Especially for devices modified with either the XStation or PSIO drive emulators, this can be a handy feature to have as this method can more easily take the user back to the emulator menu as well as physically reset the device. The modification is a small PCB which attaches to the controller port and, unlike previous versions, only requires a single pin to be soldered to the Playstation’s control board.

If you’re someone who enjoys playing games on original hardware rather than a patchwork of emulators, this could be an excellent addition to your PS1 that still allows most of the original feel and experience the PS1 offered. The drive emulator can greatly expand the range of the hardware as well, much like this NES cartridge which similarly expands the capabilities of that much older system.

A Super Easy Laser Engraver

November 26, 2019 by Lewin Day 8 Comments

CNC comes in all shapes and sizes, from huge industrial lathes to homebuilt wire benders. [MJKZZ] has built their own compact rig, using optical drive parts to create a cute but effective laser engraver. (Video embedded below.)

The build aims to keep things simple by holding the laser stationary, and moving the bed instead. The laser in question is a 500 mW unit, driven by the Z axis on the Arduino CNC shield used to run the system. A DVD drive is taken apart, and the worm drive stepper motor assembly is used to slew the carriage back and forth, atop which is glued a bed. Upon this bed, a copy of the same assembly is then installed, offset 90 degrees, giving the X and Y axes.

The result of this setup is a lightweight moveable bed, controllable through Gcode with GRBL. With the laser situated above on some camera mounting gear, paper can be installed on the bed and engraved with ease. The resulting accuracy is admirable, and at full power, the laser is capable of cutting through the paper.

While it’s a lightweight rig, it could serve a purpose as a cheap and easy way to produce stencils from computerized artwork. Optical drives remain popular in the DIY CNC scene, as they’re a great way to source a moveable platform with all the mechanical considerations already worked out.

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Tearing Down A PS3 Blu Ray Drive

November 12, 2019 by Lewin Day 16 Comments

Optical drives are somewhat passe in 2019, with most laptops and desktops no longer shipping with the hardware installed. The power of the cloud has begun to eliminate the need for physical media, but that doesn’t mean the technology is any less marvellous. [Leslie Wright] and [Samuel Goldwater] took a deep dive into what makes the PS3’s optical drive tick, back in the heyday of the Blu Ray era.

The teardown starts by examining the layout of the assembly, and the parts involved. This is followed by a deep dive into an exploration of the triple-laser diode itself, There are tips on how to safely extract the delicate parts, which are highly sensitive to electrostatic discharge, as well as exhaustive specifications and measurements of performance. There’s even a break down of the optical package, too, including a patent search to shed more light on the complicated inner workings of the hardware.

And if this lures you to dig deeper into Sam’s Laser FAQ, prepare to spend the rest of the week.

We’ve seen other optical teardowns before, too – like this look inside a stereo microscope. It’s quite technical stuff, and may fly over the heads over the optically inexperienced. However, for those in the know, it’s a great look at the technology used in a mass-produced console.