What is Applesauce?

Applesauce is a project targeting retro computing enthusiasts and digital archivists who need to work with floppy disks. It combines the most capable and full featured disk analysis software available along with powerful hardware, and packages it up into a product that it easy to use for even non-technical folks.

What kind of disks and disk images does Applesauce support?

Applesauce can image just about all popular disk formats. Applesauce goes far beyond just capturing data from a disk, it also understands many different file systems. This allows you to be able to access files within disk images without needing additional software. Applesauce also has the ability to read and write many different disk image formats. Here is a breakdown of current support, but it is very likely that disks not on this list will also be able to be imaged:

PlatformDisk TypesFile Systems RecognizedDisk Image Formats
GenericA2R (Applesauce)
IMD (ImageDisk)
KryoFlux Raw – read only
DFI (DiscFerret) – read only
SCP (Super Card Pro) – read only
MFI (MAME) – read only
Apple II5.25″ 113K (13-sector)
5.25″ 140K (16-sector)
3.5″ 800K
DOS 3.2 (13-sector)
DOS 3.3 (16-sector)
Apple Pascal
Apple CP/M
EDD – read only
NIB – read only
N35 – read only
Apple ///5.25″ 140K (16-sector)SOSDSK
Apple Lisa3.5″ 400K
3.5″ 800K
Lisa MonitorDiskCopy 4.2 (DC42)
DART (all compression levels) – read only
Apple Macintosh3.5″ 400K
3.5″ 800K
3.5″ 1.44M
DiskCopy 4.2 (DC42)
DiskCopy 6.x – read only
DART (all compression levels) – read only
Atari 8-bit5.25″ SD, ED, DDAtari DOS 2.xATR
ATX – write only
Atari ST / TT3.5″ 360K
3.5″ 720K
3.5″ 1.44M
Commodore 15415.25″CommodoreDOSD64
G64 – write only
Commodore Amiga3.5″ 880K
3.5″ 1660K
Heathkit/Zenith5.25″ 100K H-17
5.25″ 200K H-17
IBM PC5.25″ 160K
5.25″ 180K
5.25″ 320K
5.25″ 360K
5.25″ 640K
5.25″ 1.2M
3.5″ 360K
3.5″ 720K
3.5″ 1.44M
3.5″ 1.68M
North Star5.25″ 87K
5.25″ 175K
TI-99/45.25″ 90K
5.25″ 180K
5.25″ 360K
Disk Memory SystemDSK (V9T9)
TRS-805.25″ 90K
5.25″ 180K
5.25″ 360K
RDOS (CoCo)DMK – write only
Victor 90005.25″ 600K
5.25″ 1.2M

What makes Applesauce different from other flux imaging tools?

Applesauce comes fully enclosed in an attractive case with lots of blinking lights on it. Not only is it protected and easy to store, it makes for a much tidier desk that doesn’t looks like some kind of crazy science fair experiment with various circuit boards laying around. Ok, maybe your desk looks like that all the time anyway, but Applesauce won’t be contributing to the problem. Oh, and did I mention the blinking lights? They blink so nice!

It runs on the Mac! Well, let me clarify that a bit more, it runs only on the Mac. So, yeah the Apple hardware/firmware itself is completely agnostic as to the architecture and operating system of the host computer, but the client software is written for macOS 10.11 or higher. Works great with macOS 11. Runs native on x86-64 and M1. But in order to use the client on Windows or Linux, you are going to have to do so via virtualization like VirtualBox. If you don’t know what virtualization is, then we’ll keep this simple and say that it runs only on the Mac.

Lots of folks talk about how all flux imaging tools are the same. This is true to a degree. At the lowest level, they are all capturing the amount of time between magnetic flux transitions on the media. The real differentiator comes from what you do with all of these flux timings. Most tools simply take a snapshot of the disk and want you to take these results to some other piece of software to interpret what was captured. The idea of a flux image always being “exactly what was written on the disk” simply is a fallacy. In theory it sounds perfect, but the real world simply doesn’t work like that. What is actually being captured is a specific drive’s interpretation of the disk as read in that moment. Floppy disks are an analog media, not a digital one. What is read is negatively impacted by electrical interference, dirt or mold on the media surface or accumulated on the drive head, media coating damaged or flaking off, poor/inconsistent magnetic levels on the disk, and many other factors. Applesauce is a complete solution that will give you feedback during the imaging process and has the ability to immediately validate images without needing to rely on other tools.

Flux imaging a disk is just one of the ways in which Applesauce allows you to capture disk data. Applesauce also has what is known as the Fast Imager. It is designed for non copy protected disks and is extremely fast. But it isn’t about just being fast, the entire imaging flow revolves around data recovery. It doesn’t take snapshots of a disk like a flux imager, but instead it captures the sector structure of a disk and in real time will validate and retry as needed. It minimizes touching the disk as much as possible in order to not heat up the media surface which can be very bad for disks that are falling apart due to binder failure. As it captures sectors, they are stored away safely and once a track has been captured, it will never touch that track again. It also has optimized imaging patterns for how it moves the head around the surface. You can even stop the imaging process at any time in order to remove the media for cleaning or for cleaning the read head. Put the disk back in and it will resume the capture process with no loss of already captured data. And the features of the Fast Imager don’t end there. When imaging disks, almost all other flux imaging tools make you provide some technical information about the disk structure; like number of tracks and sides and sometimes encoding. This is not how Applesauce works. For Applesauce, you just press the Image Disk button. It will figure out the disk encoding, geometry, and sector structure all on its own. And for many disks, it will even figure out what file system is used, which is a nice trick. But Applesauce even takes that to another level by performing file-level validation of the disk while imaging. If you have bad sectors on the disk, it will let you know if any of the files on the disk use those sectors. The intelligence you need to determine if a disk that is in bad shape has had the important bits captured or not so that you don’t waste time trying to get sectors that aren’t even being used. All this power while being able to capture a C64 disk in 14 seconds, an 800K Mac disk in 33 seconds, an 880K Amiga disk in 27 seconds (in a SuperDrive), a 1.44M HD disk in 48 seconds, or an Apple II 5.25 disk in 19 seconds (it requires capturing each sector twice since the sector checksum isn’t very good and is easy to have a hash collision).

The Applesauce client is built to be able to capture complex user-entered and analysis-derived metadata about a disk at imaging time and the metadata is automatically captured and stored within the A2R flux image file. This file format was created for the Applesauce project, but is an open standard (details can be found here).

The Applesauce unit provides power for the floppy drive so that no separate power supply is needed. It provides +12V, +5V, and -12V. Not only does it provide clean power for your drives, it also monitors the voltage level and has ammeters on the +12V and +5V rails. When it powers up a drive, it watches the power consumption of the drive (checks 20,000 times per second) to ensure that there is nothing out of the ordinary happening. It can detect electrical shorts or other unusual conditions and can shut off the power to the drive within milliseconds in order to minimize damage to your equipment. Very conveniently, it also shuts off power to the drive whenever the Applesauce client software isn’t connected so it is safe to leave things connected up.

The Applesauce buffers all signals going to the floppy drive, so it is compatible with a wider range of older drives than some other flux tools. Applesauce also captures all flux data to internal RAM in the hardware for later transmission in a safe way. There is no streaming of data with the potential to lose data if your USB bus bandwidth dips due to other devices using it.

Applesauce fully supports hard sectored disks. It will automatically detect them as well as the number of hard sectors that exist. It will then image the disk using the true index and keep track of sector starts relative to the flux stream. If it is a hard sectored disk that contains soft sector data, then the hard sector timing will still be captured, but have no negative impact of the soft sectored data stream.

Applesauce supports both reading from and writing to disks.

There is a full set of diagnostic checks that can be performed on floppy drives. It can help you to diagnose drive issues and adjust drive speed. Not only useful for imaging, but a great way to test drives that you use with your retro gear. There is even an Analog Characteristics Analysis that can show you graphs about the amplifier, filtering, and read head output.

Applesauce is not an open source project, and there are some wild stories about why that is. But there are 3 independent people that have full access to the repository containing every scrap of source code and hardware projects about Applesauce. These people have been instructed to release everything into the public domain in the case of anything happening to me, or me getting bored and walking away from the project. It is important to me that people understand that even though it isn’t currently open source, there will never be a situation in which they will get stuck with hardware that is no longer supported or supportable. All of the file formats and such have already been fully documented and released into the public domain. I have also released documentation for the entire communication protocol between the client and hardware so that people can write their own software.

No silly licensing rules! No special institutional rules, expenses, or overreaching requirements. You are buying a tool from us. What you do with it is your business.

The client software is the most powerful disk analysis software available and is frequently updated adding new features. And it will always be free.