FluxEngine
(If you're reading this on GitHub, the formatting's a bit messed up. Try the version on cowlark.com instead.
What?
The FluxEngine is a very cheap USB floppy disk interface capable of reading and writing exotic non-PC floppy disk formats. It allows you to use a conventional PC drive to accept Amiga disks, CLV Macintosh disks, bizarre 128-sector CP/M disks, and other weird and bizarre formats. (Although not all of these are supported yet. I could really use samples.)
The hardware consists of a single, commodity part with a floppy drive connector soldered onto it. No ordering custom boards, no fiddly surface mount assembly, and no fuss: nineteen simpler solder joints and you're done.
Don't believe me? Watch the demo reel!
Important note. On 2019-02-09 I did a hardware redesign and moved the pins on the board. Sorry for the inconvenience, but it means you don't have to modify the board any more to make it work. If you built the hardware prior to then, you'll need to adjust it.
Where?
How?
This page was getting kinda unwieldy so I've broken it up. Please consult the following friendly articles:
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Frequently asked questions ∾ but why...? ∾ does it...? ∾ can it...?
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How the FluxEngine works ∾ nitty gritty of the sampler/sequencer hardware ∾ useful links on floppy drives ∾ why I'm not using an Arduino/STM32/ESP32/Raspberry Pi
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Making a FluxEngine ∾ what parts you need ∾ building it ∾ setting up the toolchain ∾ compiling the firmware ∾ programming the board
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Using a FluxEngine ∾ what to do with your new hardware ∾ flux files and image files ∾ knowing what you're doing
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Reading dubious disks ∾ it's not an exact science ∾ the sector map ∾ clock detection and the histogram ∾ tuning the clock ∾ manual adjustment
Supported disk formats
The current support state is as follows.
| Format | Read? | Write? | Notes |
|---|---|---|---|
| IBM PC compatible | 🦄 | and compatibles (like the Atari ST) | |
| Acorn ADFS | 🦄 | single- and double- sided | |
| Acorn DFS | 🦄 | ||
| AES Superplus / No Problem | 🦖 | hard sectors! and very experimental | |
| Ampro Little Board | 🦖 | ||
| Apple II DOS 3.3 | 🦖 | doesn't do logical sector remapping | |
| Amiga | 🦄 | ||
| Commodore 64 1541 | 🦖 | and probably the other GCR formats | |
| Brother 120kB | 🦄 | ||
| Brother 240kB | 🦄 | 🦄 | |
| Macintosh 800kB | 🦖 | and probably the 400kB too | |
| TRS-80 | 🦖 | a minor variation of the IBM scheme | |
| Victor 9000 | 🦖 | experimental, probably buggy | |
| {: .datatable } |
Dinosaurs (🦖) have yet to be observed in real life --- I've written the decoder based on Kryoflux (or other) dumps I've found. I don't (yet) have real, physical disks in my hand to test the capture process.
Unicorns (🦄) are completely real --- this means that I've read actual, physical disks with these formats and so know they work.
Notes:
-
IBM PC disks are the lowest-common-denominator standard. A number of other systems use this format in disguise (the Atari ST, late-era Apple machines, Acorn). FluxEngine supports both FM and MFM disks, although you have to tell it which one. If you have an unknown disk, try this; you may get something. Then tell me about it.
-
Not many formats support writing yet. That's because I need actual, physical hardware to test with in order to verify it works, and I only have a limited selection. (Plus a lot of the write code needs work.) There hasn't been a lot of demand for this yet; if you have a pressing need to write weird disks, please ask. I haven't implement write support for PC disks because they're boring and I'm lazy, and also because they vary so much that figuring out how to specify them is hard.
If you have samples of weird disks, and want to send them to me --- either FluxEngine or Kryoflux dumps, or (even better) actually physically --- I can identify them and add support.
Please note that at this point I am not interested in copy protected disks. It's not out of principle. It's just they'll drive me insane. FluxEngine will most likely be able to read the data fine, unless they're doing bizarre things like spiral tracks or partially encoded data, but let's stick with normal conventionally formatted disks for the time being!
Who?
The FluxEngine was designed, built and written by me, David Given. You may contact me at dg@cowlark.com, or visit my website at http://www.cowlark.com. There may or may not be anything interesting there.
License
Everything here except the contents of the dep directory is © 2019 David
Given and is licensed under the MIT open source license. Please see
COPYING for the full text. The tl;dr is: you can do what you like
with it provided you don't claim you wrote it.
As an exception, dep/fmt contains a copy of fmt,
maintained by Victor Zverovich (vitaut <https://github.com/vitaut>) and
Jonathan Müller (foonathan <https://github.com/foonathan>) with
contributions from many other people. It is licensed under the terms of the
BSD license. Please see the contents of the directory for the full text.