Using Excel To Manage A Commodore 64

June 8, 2023 by Bryan Cockfield 16 Comments

The “save” icon for plenty of modern computer programs, including Microsoft Office, still looks like a floppy disk, despite the fact that these have been effectively obsolete for well over a decade. As fewer and fewer people recognize what this icon represents, a challenge is growing for retrocomputing enthusiasts that rely on floppy disk technology to load any programs into their machines. For some older computers that often didn’t have hard disk drives at all, like the Commodore 64, it’s one of the few ways to load programs into computer memory. And, rather than maintaining an enormous collection of floppy discs, [RaspberryPioneer] built a way to load programs on a Commodore using Microsoft Excel instead.

The Excel sheet that manages this task uses Visual Basic for Applications (VBA), an event-driven programming language built into Office, to handle the library of applications for the Commodore (or Commodore-compatible clone) including D64, PRG, and T64 files. This also includes details about the software including original cover art and any notes the user needs to make about them. Using VBA, it also communicates to an attached Arduino, which is itself programmed to act as a disk drive for the Commodore. The neceessary configuration needed to interface with the Arduino is handled within the spreadsheet as well. Some additional hardware is needed to interface the Arduino to the Commodore’s communications port but as long as the Arduino is a 5V version and not a 3.3V one, this is fairly straightforward and the code for it can be found on its GitHub project page.

With all of that built right into Excel, and with an Arduino acting as the hard drive, this is one of the easiest ways we’ve seen to manage a large software library for a retrocomputer like the Commodore 64. Of course, emulating disk drives for older machines is not uncommon, but we like that this one can be much more dynamic and simplifies the transfer of files from a modern computer to a functionally obsolete one. One of the things we like about builds like this, or this custom Game Boy cartridge, is how easy it can be to get huge amounts of storage that the original users of these machines could have only dreamed of in their time.

Trying (and Failing) To Restore A 1970s CDC 10MB Hard Drive

February 28, 2023 by Maya Posch 33 Comments

One fun aspect of 1970s-era hard disk drives is that they are big, clunky and are fairly easy to repair without the need for a clean room. A less fun aspect is that they are 1970s-era HDDs and thus old and often broken. While repairing a CDC 10 MB HDD for the upcoming VCF East event, the folks over at [Usagi Electric], this led to quite a few struggles, even after a replacement 14″ platter was found to replace the crashed platter with.

These CDC HDDs are referred to as Hawk drives, and they make the associated 8-bit Centurion TTL logic-based computers so much faster and easier to work with (for a 1970s system, of course). Despite the large size of the components involved and the simple, all through-hole nature of the PCBs, issues that cropped up ranged from corroded DIP switches, to head alignment sensors, a defective analog board and ultimately a reported bad read-write head.

Frustratingly, even after getting the platters to spin up and everything moving as intended, it would seem that the remaining problem is that of possibly bad read-write heads, as in plural. Whether it’s due to age, previous head crashes onto platters, or something else, assembling a working Hawk drive turned out to be somewhat more complicated than hoped.

We definitely hope that the bunnies can get a working Hawk together, as working 1970s HDDs like these are become pretty rare.

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Tiny Dongle Brings The Hard Drive’s Song Back To Updated Retrocomputers

September 26, 2022 by Dan Maloney 28 Comments

Back in the “beige box” days of computing, it was pretty easy to tell what your machine was doing just by listening to it, because the hard drive was constantly thrashing the heads back and forth. It was sometimes annoying, but never as annoying as hearing the stream of Geiger counter-like clicks stop when you knew it wasn’t done loading a program yet.

That “happy sound” is getting harder to come by, even on retro machines, which increasingly have had their original thrash-o-matic drives replaced with compact flash and other solid-state drives. This HDD sound simulator aims to fill that diagnostic and nostalgic gap on any machine that isn’t quite clicky enough for you. Sadly, [Matthias Werner] provides no build details for his creation, but between the longish demo video below (by a satisfied customer) and the details of the first version, it’s easy enough to figure out what’s going on here. An ATtiny and a few support components ride on a small PCB along with a piezoelectric speaker. The dongle connects to the hard drive activity light, which triggers a series of clicks from the speaker that sound remarkably like a hard drive heading seeking tracks. A demo starts at 7:09 in the video below; the very brave — or very nostalgic — might want to check out the full defragmentation that starts at 13:11.

Sure, this one is perhaps a bit over-the-top, but in the retrocomputing world, no price is too high to pay in the name of nostalgia. And it’s still far from the most ridiculous hard drive activity indicator we’ve seen.

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Behold The Mighty Floppotron 3.0

June 14, 2022 by Dave Rowntree 37 Comments

If anyone has been struggling to get hold of a 3.5″ floppy drive lately, we think we’ve got a clue as to why — behold, the mighty floppotron 3.0 by [Paweł Zadrożniak.] With an utterly bonkers 512 floppy drives, four flatbed scanners and sixteen hard disks of various sizes, the floppotron 3.0 MIDI synthesiser is possibly the biggest such retro hardware synthesiser so far. Since every part of the system is motor-based, nobody is going to be surprised that to power the show is quite an undertaking, with nearly twenty switched-mode PSU modules needed to keep up with the demand, averaging 300W but rated at 1.2kW peak!

A full custom MIDI-to-RS485 gateway based around the nRF52xx series MCU deals with the communication to the collection of instrument controllers. These controllers are generic enough to take RS485 input and control a dedicated driver for either an array of floppy drives (up to 192), an array of hard drives or the handful of scanners. The way the floppy drives are grouped is quite neat. Rather than using each drive to generate a specific tone, the software uses the whole column for each note. By varying the number of drives moving simultaneously over time, the sound volume varies, simulating the note envelope and giving a richer sound. Multiple columns driving in parallel give the system a 16-note polyphony. The floppies cover the low notes, with the four flatbed scanners covering the higher notes. MIDI drum sounds are mapped to the hard disks, operating in a, well, percussive manner, with different case shapes giving unique sounds. Even the firmware can be updated over MIDI! So, checkout the demo video after the break for a sweet rendition of the very familiar “Entry of the gladiators” by Czech composer Julius Fučík.

If you think this looks familiar, you’re not mistaken, we’ve covered an earlier floppotron before, but we reckon nobody has attempted to do it with ye olde eight-inch drives yet!

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Controller Swaps Can Save An HDD If You Do It Right

December 11, 2021 by Lewin Day 22 Comments

Hard drives are fragile and reliable all at once. It’s entirely possible to have a hard drive fail, even if your data is still in perfect condition on the magnetic platters inside. [Keith Sherry] was recently trying to recover data for a friend off a damaged hard drive, and demonstrated that modern twists on old tricks can still work.

The drive in question was an old 160GB disk that itself was being used as a backup. Of course, a backup you haven’t tested is no backup at all, and this one failed in the hour it was most needed.

The suspicion was that the controller board was the culprit, and that swapping the board out might bring things back to life. Back in the day, this was a common hacker trick. However, it often fails with modern drives, which store a great deal of drive-specific calibration data on the controller board. Without this specific data, another controller will be unable to access the data on the drive, and could even cause damage.

However, as [Keith] demonstrates, there is a way around this. A controller from a similar drive was sourced, albeit from a SATA version of the drive versus the original which used USB. A single chip is then removed from the original controller, containing the calibration data specific to that drive. Soldering this chip onto the new controller got everything up and running, and the files could be recovered.

If your data is invaluable, it’s likely worth paying a professional. As [Keith] demonstrates though, the old tricks can still come in handy as long as your techniques are up to date. DIYing your own data recovery can be done, it’s just risky is all.

Oh, and don’t forget — once you’ve recovered the files, throw the drive away. Don’t keep using it! Video after the break.

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Mistaken Identity — Piezo Actuators Not Test Pads

June 18, 2021 by Chris Lott 16 Comments

One hard disk recently failed in the EEVBlog laboratory’s NAS. Keeping true to his catch phrase, [Dave “Tear it Apart” Jones] opened it up and gave us an inside tour of a modern hard disk drive. There are so many technological wonders to behold in modern HDDs these days — the mechanical design, electronics and magnetics, and the signal processing itself which is basically an advanced RF receiver — that we can forgive [Dave] for glossing over a system of piezo actuators thinking they were manufacturing test points. Even knowing they are actuators, you have to stare at them and think for a bit before your brain accepts it.

Later realizing the mistake, he made a follow-up video (down below) focusing on just the disk head actuator arms and this micro-actuation system (or perhaps they are milli-actuators). The basic concept is a pair of piezoelectric transducers mounted on either side of the short arm holding the read head. Presumably they are driven out of phase to flex the arm left or right, but the motion is imperceptible to the eye — even under magnification, [Dave] was not able to discern any motion when he pulsed the transducers. When you consider that these micro-actuators are mounted on the main actuator arm, which itself is also in motion, the nested control loop arrangement to maintain nanometers of accuracy is truly amazing. Check out this 45 second explanatory video by Western Digital which has a good animation of the concept.

If you want to see your HDD in operation without taking it apart, check out the transparent drive we wrote about last month. And to read more about esoteric actuators, check out this article from 2015 which contains one of the longest words to appear in our pages — magnetorheological. If you’ve experience a hard disk failure, which thankfully is becoming rarer these days, do you chunk it or tear it apart?

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The Hard Drive MIDI Controller

March 2, 2015 by Brian Benchoff 14 Comments

[shantea] builds MIDI controllers, and after a successful first endeavor with a matrix of buttons and knobs, he decided to branch out to something a little bit cooler. It’s called Ceylon, and it’s effectively a turntable controller built from an old hard drive.

As a contrast to the first MIDI controller, this would be a stripped-down build, with just three faders, LEDs for eye candy, a pair of pots for gain control, and a hard disk surrounded by six anti-vandal buttons. The hard disk is the star of the show, acting as a rotary encoder.

When manually spun, the hard disk generates a few phases of sinusoidal waves. The faster you spin it, the higher the amplitude and frequency. These signals are far too weak to be sampled directly by a microcontroller, and for digital control – as in, MIDI – you don’t need to read the analog signals anyway. These signals were turned digital with the help of an LM339 quad comparator. With two of these comparators and signals out of the hard disk that are 90 degrees out of phase, quadrature encoding is pretty easy.

The software for this MIDI controller is based on the OpenDeck Platform, a neat system that allows anyone to create their own MIDI controllers and devices. It’s also a great looking board that seems to perform well. Video below.

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