Image by [Makestreme] via Hackaday.IO[Makestreme] recently started creating YouTube videos, but wasn’t pressing Save often enough. Couple that with editing software that crashes, and the result is hours of lost work.
Just like you’d expect, pressing the floppy icon triggers Ctrl-S when connected over USB-C. Internally, it’s a Seeeduino Xiao, a push button, and some wires.
The floppy disk itself is made of foam board, and everything is encased in a picture frame. If you want to make one for yourself, [Makestreme] has some great instructions over on IO.
Back when CD-Rs were the thing, there were CD burner drives which would etch images in the unoccupied areas of a CD-R. These so-called LightScribe drives were a novelty of which most users soon tired, but they’re what’s brought to our mind by [dbalsom]’s project. It’s called PNG2disk, and it does the same job as LightScribe, but for floppies. There’s one snag though; the images are encoded in magnetic flux and thus invisible to the naked eye. Instead, they can be enjoyed through a disk copying program that shows a sector map.
The linked GitHub repository has an example, and goes in depth through the various options it supports, and how to view images in several disk analysis programs. This program creates fully readable disks, and can even leave space for a filesystem. We have to admit to being curious as to whether such an image could be made physically visible using for example ferrofluid, but we’d be the first t admit to not being magnetic flux experts.
[Folaefolc] was craving a new keyboard build a few weeks ago and got inspired by the humble 3.5″ floppy disk. So much so that he decided to make a split keyboard with each half having the exact footprint of a floppy — 90 mm x 94 mm. And you know the PCBs have floppy details silkscreened on the back. Just check out the gallery.
Image via [Folaefolc] via redditThis bad boy uses a pair of Liatris microcontrollers, which are made by splitkb and are designed to be drop-in replacements for Pro Micros and an alternative to the RP2040.
The other fun part of this build is that [Folaefolc] used RJ9 connectors to join the halves instead of something like TRRS.
These days, the vast majority of portable media users are storing their files on some kind of Microsoft-developed file system. Back in the 1980s and 1990s, though, things were different. You absolutely could not expect a floppy disk from one type of computer to work in another. That is, unless you had a magical three-format disk, as [RobSmithDev] explains.
The tri-format disk was a special thing. It was capable of storing data in Amiga, PC, and Atari ST formats. This was of benefit for cover disks—a magazine could put out content for users across all three brands, rather than having to ship multiple disks to suit different machines.
[RobSmithDev] started investigating by reading the tri-format disk with his DiskFlashback tool. The tool found two separate filesystems. The Amiga filesystem took up 282 KB of space. The second filesystem contained two folders—one labelled PC, the other labelled ST. The Atari ST folder contained 145KB of data, while the PC folder used 248 KB. From there, we get a breakdown on how the data for each format is spread across the disk, right down to the physical location of the data. The different disk formats of each system allowed data to be scattered across the disk such that each type of computer would find its relevant data where it expected it to be.
Despite the rise of ARM processors in more and more computers from embedded systems to daily driver PCs, the x86 architecture maintains a stronghold in the computing space that won’t be going away anytime soon. One of the main drivers of this is its beachhead in industrial systems; the x86 architecture is backwards-compatible farther back than many of us have been alive and in situations where machines need to run for years with minimum downtime it’s good to know you can grab any x86 system off the shelf and it’ll largely work. This is also true for gaming, so if you’re like [Yeo Kheng Meng] and want to run games like DOOM natively on modern hardware it’s certainly possible, although there are a few catches.
This build goes into the design of a modern AMD Ryzen 5 desktop computer, with all of the components selected specifically for their use running software more than three decades old now. [Yeo Kheng Meng] is targeting DOS 6.22 as his operating system of choice, meaning that modern EFI motherboards won’t necessarily work. He’s turned to business class products as a solution for many of these issues, as motherboards targeting business and industrial customers often contain more support for antiquated hardware like PS/2 and parallel ports while still having modern amenities like DDR5 memory slots. PS/2 ports additionally are an indicator that the motherboard will supports older non-EFI boot modes (BIOS) and can potentially run DOS natively. Everything here can also run modern operating systems, since he isn’t building this system only to run DOS and retro games.
Beyond the motherboard choice, he’s also using a Soundblaster card for audio which is a design choice generally relegated to history, but still used in modern gaming by a dedicated group. There’s also a floppy drive running via a USB header adapter cable. Of course, there are a few problems running DOS and other era-appropriate software natively on such incomprehensibly fast hardware (by early 90s standards). Some video games were hard coded to the processor clock of the x86 process of the era, so increasing the clock speed orders of magnitude results in several playability issues. In emulators it’s easier to provide an artificially slow clock speed, but on real hardware this isn’t always possible. But [Yeo Kheng Meng] has done a lot to get this modern computer running older software like this. Another take we’ve seen for retro gaming on original hardware is this system which uses a brand-new 486 processor meant for use in industrial settings as well.
[GloriousCow] has started working on a series of investigations into the various historical floppy disk copy protection schemes used in the early days of the IBM PC and is here with the first of these results, specifically Formaster’s Copy-Lock.
This is the starting sector of track 6. It looks empty, but it’s not quite.
The game in question is King’s Quest by Sierra Entertainment, which used a ‘booter disk’ with the Copy-Lock protection scheme. Instead of having to boot DOS separately, you could just insert this disk and the game would launch automatically. Early copy protections often used simple methods, like adding sectors with non-standard sizes or tampering with sector CRC values to create disk errors. Copy-Lock employed several such tricks together, making it challenging for standard floppy disk hardware to replicate. In the case of Copy-Lock, Sector 1 on track 6 was intentionally written as only 256 bytes, with a 256-byte blank section to fill the gap. Additionally, the CRC was also altered to add another layer of protection.
When attempting to read the disk, the PC BIOS interrupt routine assumes it’s looking for a standard 512-byte sector, so when a “read sector” command is issued to locate the sector, it never finds it. To detect a dodgy copy, the game bypasses the BIOS and talks directly to the floppy disk controller using some custom code. The first part of the code uses the standard INT 13h routine to seek to track 6, sector 1, where it expects a fail since there is no valid sector there. Next, the floppy controller sends the “read track” command to perform a raw dump of all 512 bytes at this address and looks for a magic number, 0xF7, sitting in the final byte. That empty second half of the short sector is indeed not empty and is the check the game makes to determine if it was written with the Copy-Lock capable hardware. That last point is pertinent; you can’t create this disk structure with a standard IBM PC floppy disk controller; you need specialized hardware that can write different-sized sectors and incorrect CRCs, and that costs money to acquire.
We recently covered the copy protection scheme used for Dungeon Master on the Atari ST and the Amiga. If you’re thinking less about how a floppy got cracked and copied and more about how to preserve these digital relics, check this out!
Using a disk drive today is trivial. But back “in the day,” it was fairly complex both because the drives were simple and the CPUs were not powerful by today’s standards. [Thomas] has been working on a 68000 Mac emulator and found that low-level floppy information was scattered in different places. So he’s gathered it all for us in one place.
Low-level disk access has a lot of subtle details. For example, the Mac calibrates its speed control on boot. If your emulated drive just sets the correct speed and doesn’t respond to changes during calibration, the system will detect that as an error. Other details about spinning disks include the fact that inner tracks are shorter than outer track and may require denser recordings. Laying out sectors can also be tricky since you will lose performance if you, for example, read sector one and then miss sector two and have to wait for it to come back around. Disk sectors are often staggered for this reason.
Adding to the complexity is the controller — the IWM or Integrated Woz Machine — which has an odd scheme for memory mapping I/O. You should only access the odd bytes of the memory-mapped I/O. The details are all in the post.
In a way, we don’t miss these days, but in other ways, we do. It wasn’t that long ago that floppies were king. Now it is a race to preserve the data on them while you still can.
