The modernisation of some of the vintage components in old computers comes with its own set of challenges. Things break: thirty plus year old hard drives stop spinning, floppy drive components such as a simple elastic rubber to get mechanical things moving disintegrate, and of course plenty of capacitors leak. Sometimes, things break up to the point that I sometimes wonder whether being a retro hardware enthusiast is worth it at all. The solution to these problems is simple and not so simple: de-solder the component from the board and look for a replacement, and throw out that rubber or the drive entirely to find modern replacements such as the SD-to-IDE interface I use to emulate a HDD. Fixed—now the old motherboard still thinks it’s speaking to a genuine vintage hard drive! Not fixed? The distinctive mark of a humming disk is gone: an SD card has little to say except for crack when you jump on it. The true retro enthusiast—the real appreciator of smelly electronic components that go beep—will want to hear that beep. Not just a beep, but a bzzzzzkkrrrttttt tzk tzk tzk BEEP: your classic spin-up sound when these mechanical drives start spinning. Thankfully, some retro enthusiasts are prepared to do more than just accept the fact that the noise is gone. Some go as far as building their own expansion card that fully emulates the sound of yore. This is the story of my friend Peter Bridger’s HDD Synth. Peter was kind enough to send me two prototypes to play with1; his third revision (Mark III) of the idea, as pictured below, currently in the state of an ISA card. The HDD Synth Mark III, with a 3D-printed bracket screwed on. The first thing I thought when I heard the idea was: how is this going to work if your sound card’s drivers are loaded only after the bootup procedure? Peter’s design makes use of another speaker mounted on the card, separate from your sound card or built-in PC Speaker. It leverages the Raspberry Pico to output sampled sound directly to the custom speaker by listening to the ISA port for HDD activity. Earlier models used the HDD LED in pins on the board to detect activity. As I type this, Peter is working on Mark V to reduce the footprint of the card, including getting rid of the requirement of an ISA slot to enable putting this inside older non-IBM PCs as well. One of the coolest aspects of the HDD Synth is its ability to load custom samples as well. The SD card slot is there to hold both firmware & configuration as well as custom sound samples. This allows the card to emulate any kind of vintage hard disk drive, playing just the right sound for you to evoke that instant jolt of nostalgia. Just add four files in a subdir inside samples: access.wav (the rattling when the HDD used to be busy), spindown.wav (power off), spinup.wav (power on), and idle.wav (general background noise). The settings.json configuration file looks to be fairly straightforward: { "PLAY_SPINUP": true, "PLAY_SPINDOWN": true, "PLAY_IDLE": true, "ACCESS_HOLD_TIME_MS": 500, "VOLUME_DEFAULT": 0.9, "BALANCE_DEFAULT": 0.2, "SAMPLE_PACK": "Mark1", "SIMULATION_MODE": false } Here, a subdir samples/Mark1—in my case a preset one matching my memories quite well—exists on the SD card where the samples live.The only problem I so far encountered was powering off the computer that too quickly discharges all energy resulting in spindown.wav being cut off halfway through. Even though the HDD Synth is still in beta phase, Peter put in a lot of effort to create an experience: the commissioned stickers remind me of the Game Boy’s Play It Loud campaign and the instruction manual was modelled after the original Sound Blaster manuals, detailing every pin and suggesting troubleshooting tips. As the sticker portraying a PC fan emitting a MHDDLA sound states: I’m A Big Fan! Get it, fan? No? I thought that was a good one. The HDD Synth manual inspired by the original Sound Blaster manuals. The peripheral card currently claims an ISA slot, but as stated, in future versions the card will shrink and the need for a slot will disappear. Apparently, Peter received the request to build something similar that will fit inside a MacBook. Bring Back The Noise, stupid silent MacBook Air I’m typing this on! I’ll be very curious to see how this will pan out. The card’s hardware (and software) design is fully open-sourced so if you’re a capable electronics expert you can order all the components and solder them on yourself. Thank you Peter for letting me try out one of the prototypes. I feel very honoured to be mentioned in the special thanks print on the back of the PCB. Please keep an eye on Peter’s site Strife Streams for more retro goodness and HDD Synth updates. I now own two cards thanks to the Belgian Post and customs service. There is little need in plugging in two HDD Synths in one machine. Or is there? If anyone is interested in checking out the project, let me know and I’ll send you one! ↩︎ Related topics: / pc hardware / soundblaster / By Wouter Groeneveld on 1 September 2026.  Reply via email.