RELEASE_NOTES

************************************
** FlashFloppy Release Notes
** Keir Fraser <keir.xen@gmail.com>
************************************

** v4.7a - 4 December 2022
 - Contains fixes up to v3.38 from v3 stable release series

** v4.6a - 29 July 2022
 - AUTOBOOT / HxC Mode: Fix "Error ... LBA Change test failed!"

** v4.5a - 29 July 2022
 - Contains fixes up to v3.34 from v3 stable release series
 - Supports AT32F435 MCU and SFRKC430.AT4.35 PCB

** v4.4a - 11 January 2022
 - DSK: Async I/O fixes
 - IMG.CFG: New option step= allows to specify double-step operation
 - FF.CFG: New  option max-cyl= allows limiting head-step range

** v4.3a - 14 December 2021
 - QuickDisk: Ported to new async I/O framework
 - Various I/O bug fixes

** v4.2a - 13 October 2021
 - DSK: Ported to new async I/O framework
 - ringio: A few bug fixes

** v4.1a - 2 October 2021
 - Contains fixes/features up to v3.29 from v3 stable release series
 - Do not use index_suppressed if starting rd DMA is slow
 - ringio: Do not lose write for unaligned wd_prod
 - hfe: Protect HFEv3 against a broken run of 1s

** v4.0a - 10 August 2021
 - Contains fixes up to v3.28 from v3 stable release series
 - New asynchonous I/O handling (Eric Anderson / ejona86)
   - Smarter prefetching of cylinder data
   - Smarter writeback of modified tracks/sectors
   - More accurate emulation
 - Hard sector HFE image support (Eric Anderson / ajona86)

** v3.23 - 31 December 2020
 - OLED/LCD: Fix missing folder name display row when inserting USB drive
 - IMG.CFG: New examples for Roland, Sinclair QL, Kaypro
 - IMG.CFG: Now supported in HxC-compat and indexed navigation modes
 - IMG: Fix default 8-inch single-density data rate
 - IMG, HFE: Support 255-cylinder image files

** v3.22 - 17 November 2020
 - Fix various crashes when mounting a Flash drive with stale IMAGE_A.CFG
 - FAT FS: Support filesystems for which cluster table is "too small"
   - Windows and Linux will mount these volumes, thus so should we
 - FF.CFG: New OLED display-type option: -inverse
   - Reverse-video effect (black text on white background)
 - FF.CFG: display-order= option affects normal display modes only
   - Ignored in all banner and menu modes, to avoid jumbled display
 - FF.CFG: Fix display-type parsing for OLED-specific options
   - Ignore them unless an OLED display is explicitly configured

** v3.21 - 26 October 2020
 - Support GUID Partition Table (GPT)
   - Now support: GPT, MBR, and no partition table
 - FatFS: Updated to R0.14, patchlevel 2
 
** v3.20 - 15 October 2020
 - Eject Menu: Replace Clone with Copy/Paste
   - Allows an image to be copied to a different folder
   - Navigation mode: Copy to selected folder by holding Select for 1.5s
 - FF.CFG: New option "rotary=v2" to use v2.x encoder logic
   - Fixes a very few encoders which don't work with stricter v3.x logic
 - FF.CFG: New option "twobutton-action=htu"
   - Implements hundreds/tens/units button actions of the factory firmware
 - IMG.CFG: New parameters:
   - tracks: Track-scoped parameter lists (geometry can vary by track)
   - h: Override default IDAM Head field
   - gap4a: Override default post-index track gap
 - IMG.CFG: Tag names are now case insensitive
 - IMG.CFG: Tag by file size and/or name
 - IMG.CFG: Implement some example configurations under examples/Host/
 - IMG: Fix some of the more bizarre default track geometries

** v3.19 - 28 September 2020
 - Amiga, ADF: Fix X-Copy verified writes with out-of-order sectors
   - Remember the latest written sector order for current cylinder
   - Forgotten after head step or disk eject but sufficient for X-Copy
 - FF.CFG: New interface= options 'jppc' and 'jppc-hdout'
   - jppc: pin2=nc, pin34=RDY, Japanese PC standard
   - jppc-hdout: As above but pin2=HD_OUT, similar to ibmpc-hdout
   - akai-s950 is retained as a legacy alias for jppc-hdout

** v3.18 - 23 September 2020
 - OLED/LCD: Fix potential minor display corruption
   - Only seen with 128x64 OLED displays, bottom right corner
 - alt/logfile: Write FFLOG.TXT to correct folder (root or FF/)
 - IMG, DSK: Various cleanups to sector-write handling

** v3.17 - 17 September 2020
 - DSK: Fix infinite loop when trying to open a bad DSK image file
 - Quick Disk: Restart read stream immediately after a write
   - QD support now works on Sharp MZ-800
 - IMG.CFG: Remove [default] stanza from example config
   - Users copying the example file will no longer break their IMG files

** v3.16 - 22 August 2020
 - Rotary encoder: Velocity curve during image navigation
   - Fast spin of the encoder skips multiple entries per click
 - LCD/OLED/OSD: Fix image name when display is wider than 24 characters
 - HFE: Fix double-step HFE images (broken since v3.14a)
 - HxC Compat: Strip filename extension from image name display row

** v3.15 - 23 July 2020
 - New stable release series
 - Improve rotary encoder robustness by sampling at 4x higher rate

** v3.14a - 15 July 2020
 - Properly implement non-existent tracks as empty / unformatted
   - In particular this avoids writing tracks beyond end of disk image
   - See issue #309: Could corrupt HFE images
 - Akai IMG: Implement track skew (faster access and fixes Oberheim DPX)
 - Speaker: Rate-limit step pulses at the speaker
   - Avoids high-freq chirp in Direct Access mode and Gotek-aware fast loaders
 - HxC Compat, v9-FF:
   - Atari ST keymap is now QWERTY
   - Remove unused settings from drive setup menu
   - Fix the search/filter box (Esc and Backspace keys)

** v3.13a - 13 March 2020
 - FF.CFG: New option 'write-drain=eot'
   - Fixes writes to Gotek on Amstrad PPC series (#320)
 - FF.CFG: New option 'display-on-activity=sel'
   - Turns on display whenever the Gotek drive is selected by host
 - HFE: Respect double-step header flag
   - Fixes 180k disk images on Amstrad PCW (#318)

** v3.12a - 7 February 2020
 - IMG: Support IBM 3174 1.2M and 2.4M formats (host=ibm-3174)
 - HxC: Fix HxC mode with no file selector (AUTOBOOT.HFE)
 - FF OSD: Fix dual-display operation with slower OLED
   - Wait for OLED to initialise when display-type=oled...

** v3.11a - 30 December 2019
 - LCD/OLED: Fix subfolder name, as shown in 3- & 4-row displays
   - Subfolder wasn't updated correctly when moving to parent (..) folder

** v3.10a - 28 December 2019
 - Bootloader: Wait for buttons to be pressed then released...
   - ...before starting firmware update process
   - Avoids an infinite loop when reprogramming Bootloader itself
 
** v3.9a - 27 December 2019
 - IMG: Fix density-select pin output for HD images
   - Fixes 'pin02=dens' and 'interface=ibmpc-hdout'
   - Bug has existed since v2.2a
 - Rotary Encoder: Improve tracking
   - Higher frequency, and better debounce algorithm

** v3.8a - 10 December 2019
 - USB: Fix buffer overflow when parsing string descriptors
   - Fixes crash with recent SanDisk Ultra Fit drives
 - HxC Compat, v8-FF: Fixes startup crash on Atari ST
 - Amiga: Fixes for "interface = amiga" setting
 - TR-DOS (TRD): Fix geometry when TR-DOS header is incomplete
 - Quick Disk: Larger read/write window in default blank image
 - GCC9 build fixes

** v3.7a - 11 November 2019
 - Quick Disk Bug Fixes
   - Fix write offsets and lengths within QD track
   - Filter ADF images from navigator: only QD images supported
   - Extra logging in FFLOG.TXT for debug purposes
 - Amiga AutoSwap new title: Gobliiiins
   - Thanks to Arkadiusz Makarenko!
   - https://github.com/keirf/flashfloppy-autoswap/wiki/Downloads

** v3.6a - 13 October 2019
 - Quick Disk Initial Release
   - New firmware and blank QD image in alt/quickdisk
   - Documentation in the Wiki
 - Update HxC Compat to v7-FF
   - Fix failure when booted on unmodded A1200 ESCOM boards

** v3.5a - 9 October 2019
 - New Main Menu: Press Prev/Next or Select with no Flash drive inserted
   - Factory Reset, Firmware Update, OSD Config
 - OSD: Must be updated to latest version: v1.7 or later!
 - OSD: Receive Gotek button commands via I2C
 - OSD: Default to 40 columns if no other display is connected
 - TR-DOS (TRD): Fix geometry detection based on TR-DOS header

** v3.4a - 25 September 2019
 - FF OSD support
   - Bus sharing with existing LCD/OLED display
   - Gotek buttons can be remoted to FF OSD for OSD configuration

** v3.3a - 8 July 2019
 - FF.CFG: New Disk-Change Reset option: chgrst=delay-N
   - Automatically clears the DSKCHG signal Nx0.5s after disk insertion
   - chgrst=delay-3 fixes Disk Change on Ensoniq EPS synths
 - Change head-step signal handling to reduce interrupt rate
 - OLED/LCD: Fix current-folder display line for image-on-startup=init|static
 - image-on-startup=static: The static image is now specified in INIT_A.CFG

** v3.2a - 25 June 2019
 - OLED: New default layout for 128x64 displays
 - LCD: Support 20x4 character displays
 - LCD: Row ordering is configurable
   - FF.CFG: Rename oled-text= to display-order= to reflect this
 - Eject menu: Confirmation required for Delete/Clone operations
 - Trackball: Reduce jitteriness by adding simple inertia

** v3.1a - 13 June 2019
 - OLED: Text height and content can be configured (FF.CFG:oled-text=)
   - New default for 128x64 displays presents a new third text row
 - LCD/OLED: Present an action menu when an image is ejected
   - Includes Clone and Delete Image operations

** v3.0a - 10 June 2019
 - Disk Change Reset: Emulate explicit Reset signal of certain vintage drives
   - Requires a hardware modification and FF.CFG: chgrst=pa14
 - Support ZHONGJY_TECH 2.23" 128x32 displays based on SSD1305 controller
   - FF.CFG: display-type=oled-128x32-ztech

** v2.13 - 7 June 2019
 - HFE: Fix read buffering error
 - Update HxC Compat to v6-FF
   - More robust error checking on writes

** v2.12 - 2 June 2019
 - HFEv3: Support flaky/weak bytes
 - LCD/OLED: Improve power-on initialisation robustness
 - Roland: Direct support for *.OUT images
 - IO-Test: New alternative firmware to test Gotek I/O pins
   - https://github.com/keirf/flashfloppy/wiki/Testing-IO-Pins

** v2.11a - 23 May 2019
 - Simpler bootloader update process with all-in-one update file
 - Update firmware via SD card (enhanced Goteks with SD card slot)
 - FF.CFG: sort-priority= to prioritise folders vs files during navigation
   - Default: Folders are listed before files

** v2.10a - 20 May 2019
 - Fix breakages since v2.2a:
   - host=acorn: *.ADF handling
   - host=tandy-coco: *.DSK handling

** v2.9a - 17 May 2019
 - FF.CFG: New option motor-delay= to provide emulation of motor behaviour
   - Requires modification of a standard Gotek PCB (see Wiki: Hardware Mods)
 - Debug logging: An alternative firmware is provided to log to FFLOG.TXT
   - Find the alternative update file in alt/logfile/
   - Use this for personal interest or as directed by me for debugging
   - Not for general use!
 - IMG/DSK: Better RAM handling (more space for mass-storage block cache)
 - Code optimisation (MFM decode speeded up 4x)
 - Small fix to generate INDEX signal when starting read near end of track

** v2.8a - 10 May 2019
 - DSK, IMG: Fix small error in generated MFM data
 - Increase write buffer to 32kB, enough for a full high-density track
   - More reliable whole-track writes, especially to HFE images
 
** v2.7a - 23 April 2019
 - Sort folders into alphabetical order during direct navigation
   - FF.CFG: folder-sort= to modify this new default behaviour
 - Fix memory corruption issues (stack overflow)
 - ATR: Interleave sectors for best performance over slow SIO interface

** v2.6a - 14 April 2019
 - Fix feature breakages in v2.5a
   - SSD/DSD/TRD auto-extend feature
   - FF.CFG: eject-on-startup=yes feature
 - Update HxC Compat to v5-FF

** v2.5a - 12 April 2019
 - Fragment-offsets cache implemented at the FAT filesystem layer
 - Block cache implemented at the mass-storage volume layer
   - Faster image selection/navigation in large folders
   - Improved reliability in image handling (reduced access latencies)
   - USB stick will usually stop flashing when drive is not being accessed!
 - FF.CFG: New rotary input options
   - 'trackball': Blackberry-style trackball
   - 'buttons': Push-to-ground Prev/Next buttons

** v2.4a - 9 April 2019
 - This release fixes many raw track formats (SSD, DSD, OPD, VDK, ...)
   - Thanks to John Gray for bug report, and testing!
 - RAW: Fix FM track generation
   - FM and IAM flags not plumbed through from front-end image handlers
 - RAW: Fix interleaved/skewed track generation
   - Data fetch not loading sectors from image file in the right order

** v2.3a - 8 April 2019
 - OLED: Auto-detect SSD1306 vs SH1106 display controller
   - FF.CFG: 'display-type = ...-sh1106' is now redundant and ignored
 - ATR: Fix readability of downloaded ATR images
   - Invert data as it is read/written, mirroring the standard XF551 interface
   - Thanks to Piotr for this report (using his XF551 clone)

** v2.2a - 5 April 2019
 - New image types supported:
   - XDF: 3.5" HD eXtended Disk Format (1840kB)
   - ATR: Atari 8-bit
 - 7-Seg LED: Improved track display.
   - Remove option 'led-trk' from FF.CFG. Track display mode is always on.
 - OLED: Fix horizontal offset on SH1106 128x32 displays
 - IMG.CFG: 'id' parameter simplified; 'sskew' renamed 'hskew' (head skew)
 
** v2.1a - 26 March 2019
 - IMG.CFG: Allow up to 256 sectors per track
 - IMG.CFG: Split skew into per-cylinder and per-side values (cskew/sskew)
 - IMG.CFG: Introduce image-file layout option (file-layout=<csv-list>):
   - sequential,interleaved: Cylinder-first or side-first track ordering
   - reverse-sideN: Side-N cylinders in reverse order (high to low) (N=0,1)
   - sides-swapped: Ordering of disk sides is swapped in the image file
 - 7-Segment LED: Display track number when an image is mounted
   - FF.CFG: "display-type = led-trk"
   - Displays slot number as usual during image selection/navigation
   - First button press reverts to slot display; Next press begins navigation
 - LCD/OLED: Display full cylinder number on displays wider than 16 columns
   - Previously truncated at cylinder 99

** v2.0a - 14 March 2019
 - IMG: Allow geometry to be manually configured in new file IMG.CFG
   - See examples/IMG.CFG for documentation
   - Multiple formats can be defined; distinguished by image name tags
 - IMG: Support FM mode with Index Address Mark (IAM)
 - IMG: Support auto-configuration of GAP3 (post data gap) when using IMG.CFG
 - FF.CFG: Fix parsing of comma-separated values
 - Indexed Mode: Allow arbitrary image name after "DSKAnnnn" prefix
   - eg. DSKA0000_myimage.img, DSKA0002_another.adf
 - Indexed Mode: Allow the "DSKA" prefix to be changed (FF.CFG:indexed-prefix=)

** v1.0 - 4 February 2019
 - Game/demo AutoSwap-disks feature
   - No manual disk swapping, at all!
   - Requires patching of host software titles
   - Amiga titles so far (github:keirf/flashfloppy-autoswap):
     - Beneath a Steel Sky
     - Indiana Jones and the Fate of Atlantis
     - The Secret of Monkey Island
     - Monkey Island 2: LeChuck's Revenge
 - FF.CFG: New OLED display-type sib-option "-narrower"
   - 16-character-wide display (c.w. "-narrow" 18-char-wide)
 - PC98: Direct support for HDM image files
 - HxC Compat: Small fixes to Amiga file selector

** v0.15 - 8 January 2019
 - Support Enhanced Gotek with SD card connector
   - Board requirements are in the wiki (Hardware Mods)
   - USB drive, if inserted, takes priority over SD card
   - SD card is not supported for firmware update

** v0.14 - 7 December 2018
 - Direct Access: Fix broken sector writes (USB corruption)
   - Primarily affected the CPC/ST file selectors (not Amiga)
   - Broken since v0.12

** v0.13 - 2 December 2018
 - IMG: Support Casio FZ-1 (host=casio)
 - IMG: Support SC Prophet 3000 (host=akai)
 - Display D-A/DA/"Host Direct Access" in host file selector

** v0.12 - 27 November 2018
 - IMG: Support Nascom 1 & 2 (host=nascom)
 - Direct Access: Support FM/SD access on cylinder 254
 - Direct Access: Support CMD_SELECT_IMAGE (cmd #4)
 - HxC Compat: Fix occasional "LBA Change Test Failed" error
 - Improvements to ribbon-upside-down checks

** v0.11 - 1 November 2018
 - Detect and report upside-down data ribbon cable
 - FF.CFG: Configurable OLED brightness/contrast (oled-contrast=)
 - FF.CFG: Configurable head settle time (head-settle-ms=)
 - FF.CFG: Fix comma-separated-list parsing (eg. rotary=)

** v0.10 - 30 October 2018
 - FF.CFG: Allow up/down inputs to be reversed
   - Reverse original two buttons (twobutton-action=reverse)
   - Reverse rotary encoder direction (rotary=reverse)
 - Modified version numbering scheme and remove alpha status

** v0.9.31a - 28 October 2018
 - HFE: Sanity-check critical header fields
 - FF.CFG: Better docs on pin02/pin34 options
 - HxC Compat: File selector updates

** v0.9.30a - 9 October 2018
 - TI99: Fix V9T9/DSK double-sided images
 - HxC Compat: Enter slot-based mode even with no AUTOBOOT.HFE
 - HFE: Support HFEv2 images

** v0.9.29a - 17 September 2018
 - New and improved image handlers:
   - ST: Fix 80-cyl single-sided images
   - IMG: Kaypro (host=kaypro)
   - IMG: MSX fix 40-cyl/5.25" formats (host=msx)
   - IMG: PC-DOS fix missing IAM (host=pc-dos)
   - IMG: All: Support long sectors (>1024k)
 - Indexed mode: Don't require DSKA0000 image

** v0.9.28a - 26 August 2018
 - New image types supported:
   - IMG: Fluke 9100 (host=fluke)
   - MBD: Spectrum MB02
 - LCD/OLED: Display folder names in brackets

** v0.9.27a - 27 July 2018
 - Direct Navigation: Fix hidden-file and dot-file filtering
 - Direct Navigation: Filter __MACOSX/ resource-fork folders

** v0.9.26a - 24 July 2018
 - DSK (CPC): More fixes for copy-protected tracks
 - New image types supported:
   - JVC, DSK: Tandy Coco (host=tandy-coco)
   - VDK: Dragon

** v0.9.25a - 18 July 2018
 - DSK (Spectrum, CPC, Sam Coupe): Fix tracks with little or no data in them
 - FF.CFG: New options pin02= and pin34= allow precise interface configuration

** v0.9.24a - 9 July 2018
 - DSK (Spectrum, CPC, Sam Coupe): Bug fixes. Please upgrade!

** v0.9.23a - 6 July 2018
 - DSK (Spectrum, CPC): Support weak-data copy protection
   - Used on most of the top commercial titles
 - OLED: Utilise all rows on 128x64 displays
 - LCD: Support up to 40x2 displays
 - SSD, DSD (BBC): Add correct sector skew across tracks
 - IMG: 1680kB DMF has 2:1 sector interleave

** v0.9.22a - 20 June 2018
 - OLED: Support SH1106 controller (1.3-inch displays)
   - FF.CFG: display-type = oled-128x64-sh1106
 - Support a wider range of rotary encoders
   - FF.CFG: rotary = quarter | half | full
 - New image types supported:
   - D81: Commodore 64 1581
   - IMG: DEC RX33, RX50 (host=dec)

** v0.9.21a - 11 June 2018
 - New default 6x13 font (Codec, by Chris Cannam)
 - IMG: Support MSX (host=msx)
 - Accelerate the stock Gotek buttons when using a rotary encoder
   - FF.CFG: "twobutton-action = rotary-fast"
 - HxC-Compat File Selectors:
   - New font on Amiga and Atari ST
   - Faster folder navigation on Amiga

** v0.9.20a - 6 June 2018
 - New image types supported:
   - IMG: UKNC/DVK (Soviet PDP-11 clones) (host=uknc)
   - IMG/FDI: NEC PC-98 (host=pc98)
   - IMG: Common retro IBM/PC formats work out of the box
   - IMG: Detect disk layout from PC DOS BPB (host=pc-dos)
 - Auto-extend truncated images (SSD, DSD, TRD images only)
   - "extend-image=no" disables this feature

** v0.9.19a - 1 May 2018
 - Amiga: Support high-density disk images
   - ADF: 1760kB images
   - Generate HD-ID pattern on pin 34 (interface=amiga)
 - DSK: Fixes for Sam Coupe, and others with long tracks

** v0.9.18a - 19 April 2018
 - Fix HxC compatibility mode ("LBA change test failed")
 - SDU: Improve geometry detection
 - More bug fixes to read-data ring-buffer handling
 - LED 888 Display: Show firmware version when right/up button pressed
 - LCD/OLED: When browsing through images, reset scroll to start of each file

** v0.9.17a - 17 April 2018
 - New image types supported:
   - Acorn DFS SSD/DSD
   - Acorn ADFS 'S' (160kB)
   - Akai 800kB (host=akai)
   - Memotech IMG (host=memotech)
   - SAB Diskette Utility (SDU)
   - TI-99/4A DSK/V9T9 (host=ti99)
 - New interface types supported:
   - Akai S950 (interface=akai-s950)
 - Bug fixes to read-data ring-buffer handling
 - HFE: Improve write performance (batch reads/writes up to 8 blocks)
 - OLED: Increase default initialisation probe to 3s
 - USB: Respect volume write-protect status

** v0.9.16a - 16 March 2018
 - Support ADFS D/E/F images (suffix *.ADF, FF.CFG: host=acorn)
 - Direct Access: Fix sector data CRCs
 - Reliability improvements for Acorn systems (index-suppression=no)
 - Rearrange floppy read/write buffering to avoid corruptions

** v0.9.15a - 9 March 2018
 - UI: Fix subfolder navigation when returning to parent folder (#66)
 - OLED: Auto-detect OLED displays at I2C address 0x3d
 - ST: Mimic TOS by applying track skew to ST image files (#44)
 - 7-Seg LED: Allow write protection to be toggled as on LCD/OLED
 - Support Ensoniq DD/HD custom IMG formats (host=ensoniq)
 - Support IBM PC interface with density select (interface=ibmpc-hdout)
 - Direct Access: Support track with fewer than 8 data sectors (#62)

** v0.9.14a - 4 March 2018
 - Fix write pipeline: record track number for delayed write processing
 - General Music (GEM): New host option "host=gem" for direct IMG support
 - Direct support for Spectrum Opus Discovery (OPD) image files
 - HFE, ADF: Batch writeback to the USB drive where possible
 - FF.CFG: Replace "index-during-seek" with "index-suppression"
 - Direct Access: Restart read at correct track position after a write

** v0.9.13a - 1 March 2018
 - HFE: Emulate non-standard drive speeds (eg. Sony 600 RPM drive)
 - HFE: Fix single-sector writes (broken since v0.9.8a)
 - Direct Access: Support up to 64-sector track (Atari ST HxC Mount)
 - Direct support for Spectrum TR-DOS (TRD) image files

** v0.9.12a - 27 February 2018
 - LCD/OLED: Long filenames scroll during navigation
 - LCD/OLED: Make filename scrolling more configurable
   - FF.CFG: {nav,display}-scroll-{rate,pause}
 - Direct navigation: ".." returns to subfolder position within parent
 - Fix head-seek settle time emulation
 - ADF: Generate longer tracks, like a real Amiga would

** v0.9.11a - 23 February 2018
 - Fix Direct-Acesss mode (as used by HxC Autoboot, broken in v0.9.10a)

** v0.9.10a - 22 February 2018
 - New default OLED font 6x13 displays more text per line
   - 7x16 font removed
   - 8x16 font MAY be removed, let me know if you use it!!
 - Narrow OLED view (default Gotek display cutout) supported
   - FF.CFG: display-type = oled-128x32-narrow
 - All images can be write-protected by default
   - FF.CFG: write-protect = yes
 - Write-protect switchable by holding eject for 2 seconds

** v0.9.9a - 19 February 2018
 - Fix write problems present in v0.9.8a (issue #53)
 - Support rotary encoders with proper Gray code output
   - FF.CFG: rotary = none | simple | gray

** v0.9.8a - 8 February 2018
 - Pipelined writes
   - New writes are buffered while older ones are written to the USB drive
   - More reliable write/format/disk-copy operation with slower USB drives
 - FF.CFG: Allow OLED display to be rotated 180 degrees (upside down)
   - display-type = oled-128x32-rotate
 - FF.CFG: Support BBC Micro with 8271 controller
   - Index pulses must continue during seek (index-during-seek = yes)
   - Index pulses must not be delayed by seek (track-change = realtime)

** v0.9.7a - 29 January 2018
 - Performance & reliability improvements (eg. Github issues #35, #44):
   - Sync data read after writes, prevents host missing next sector
   - FF.CFG: Sync data read after track change (track-change=instant)
     - Prevents host missing the first sector
     - Old behaviour is configurable (track-change=realtime)
 - FF.CFG: host=akai, support Akai synths with 1.6MB HD IMG files

** v0.9.6a - 17 January 2018
 - USB: Fix power-on initialisation for some USB sticks
 - FAT: Write-protect image files marked with read-only attribute
 - ST: Support 11-sector .ST images

** v0.9.5a - 1 December 2017
 - FF.CFG: New button assignment for rotary-encoder setup
   - twobutton-action = rotary
 - FF.CFG: Allow navigation mode to be specified
   - nav-mode = native | indexed | default

** v0.9.4a - 30 November 2017
 - Automatic support for crippled 'diymore' OLED displays
   - FF.CFG: New option display-probe-ms (replaces startup-delay)
 - FF.CFG: New option twobutton-action allows eject on two-button press

** v0.9.3a - 22 November 2017
 - DSK: Fix disk write handling
 - HFE: Improve read speed for HD images, reduce buffer underruns

** v0.9.2a - 21 November 2017
 - DSK: Improve handling of per-sector status codes
 - Fix bugs in front-end file handling & folder navigation

** v0.9.1a - 16 November 2017
 - Acorn ADFS image support (ADM, ADL) [Daniel Jameson]
 - Better detection of DSK image type (CPC-DSK vs raw sector file)

** v0.9.0a - 15 November 2017
** Amstrad CPC / Spectrum +3 DSK support
 - DSK directly supported for read and write. Please report any issues!
 - Improved error reporting
 - New FF.CFG option "startup-delay = N"

-------------------------------------------------------------------------

** v0.8.8a - 7 November 2017
 - Better error reporting (filesystem, media, power, image handling)
 - Optional feature enhancements for Gotek clones
 - Third button (select) may be used instead of prev/next for firmware
   update and factory reset

** v0.8.7a - 17 October 2017
 - Start in ejected state if button pressed or image previously
   ejected (when "image-on-startup = last")
 - Divide the configuration flash page into multiple slots to
   reduce the number of erase cycles when FF.CFG is repeatedly
   modified

** v0.8.6a - 13 October 2017
 - New FF.CFG option image-on-startup
 - Rename LASTDISK.IDX to IMAGE_A.CFG
 - If image-on-startup is a folder, go directly into image selector

** v0.8.5a - 13 October 2017
 - Cache FF.CFG values in Flash memory for next power on, replacing
   'factory defaults'. Restore defaults by pressing both buttons.
 - Glitch filter for SIDE-select signal (Kingstener)
 - Small improvements to FF.CFG option and value naming

** v0.8.4a - 11 October 2017
 - Bootloader OLED Display Fix (display was not enabled in update mode)
 - Integrate 7x16 OLED font into main build, configurable in FF.CFG

** v0.8.3a - 10 October 2017
 - Always search for HXCSDFE.CFG/AUTOBOOT.HFE in root folder, even
   when FF/ subfolder exists

** v0.8.2a - 10 October 2017
 - Parse FF.CFG file (see examples/FF.CFG for options)
 - LCD/OLED: Don't display bogus 'folder depth' in Autoboot mode

** v0.8.1a - 30 September 2017
 - Fix config-less navigation with simple digit displays
 - Respond to USB stick pull when in ejected state
 - LCD/OLED: Increase activity timeout to 60 seconds
 - LCD/OLED: Turn on display on drive activity

** v0.8.0a - 29 September 2017
** Subfolder support
 - Navigate subfolders in config-less mode
 - All config files can now be stored in FF subfolder
 - LASTDISK.IDX file now stores full path to the selected image
 - OLED: Display turns off after timeout (same as LCD backlight)
 - Wrap slot number at 0 and max when navigating
 - Easter egg for Anders Kling. Thanks for your support!

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** v0.7.4a - 25 September 2017
 - Fix RDATA handling, specifically when drive B on an Amstrad CPC.
   Reported by ikonsgr (EAB / Ebay) -- Thanks!

** v0.7.3a - 24 September 2017
 - HxC: Respect autoboot- and ejected-on-startup flags
 - Support 3rd button for eject and for immediate (re-)insert
 - Do not wrap slot number at 0 and max.

** v0.7.2a - 21 September 2017
 - Fixes to track timing and index position
 - Properly emulate a single-headed drive

** v0.7.1a - 21 September 2017
 - HFE: HFEv3 support
 - HFE: Correctly set bitcell size for writes
 - HFE: Reliability fix, read whole USB-disk sectors
 - ADF: Support a wider range of ADF sizes

** v0.7.0a - 19 September 2017
** IMG/ST image handling. Rotary Encoder support.
 - IMG and ST image files directly supported for read and write.
   Please report any issues!
 - Connect a rotary encoder to use in place of directional
   buttons: Thanks to Fook42 (A1K/EAB). Documentation describes
   how to connect.

-------------------------------------------------------------------------

** v0.6.3a - 18 September 2017
 - Remove Amiga AUTOBOOT.HFE and config files from the distribution.
   The HxC original files work fine, so forking is unnecessary.
 - Resync index pulse after write handling: this dramatically
   speeds up FAT filesystem access in the AUTOBOOT file selectors.
 - Reorganise and update the documentation.

** v0.6.2a - 13 September 2017
 - Prettier 7x16 'narrow' LED font (Kingstener)
 - Remember last-selected slot in no-config mode (LASTDISK.IDX file
   must exist). Thanks to Fook42 (A1K/EAB).
 - Ignore glitches on SIDE-select signal (fix for Eric Gustafson's A3000)
 - Various fixes for file selector on Atari ST and Amstrad CPC
 - Suppress index pulse when writing to USB stick. Makes slow writes
   more reliable (avoids timeouts on the host).
 - Optimised memory copying and clearing

** v0.6.1a - 31 August 2017
 - Support 2-digit LED display
 - Suppress LCD update of side number when another drive is selected

** v0.6.0a - 24 August 2017
** PC Interface Support. OLED Fixes & Narrower Font Support.
 - Allow PC Floppy Interface (DSKCHG on pin 34) to be selected via a
   jumper at position JC. Default interface (no jumper at JC) remains
   Shugart, as compatible with many non-PC systems including Amiga.
 - Kingstener: Support narrower 7x16 OLED font. Allows entire display to be
   visible through the 3-digit cutout in the Gotek case. This is a separate
   firmware build, update file is in distribution subfolder alt/.
 - OLED reliability fixes.

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** v0.5.0a - 15 August 2017
** Greater stability on A1200 and accelerated Amigas
 - I/O latency reduced on drive select/deselect. Results in more reliable
   drive detection on A1200, with and without accelerator, and on warm
   and cold reboots.

-------------------------------------------------------------------------

** v0.4.4a - 14 August 2017
 - Improvements to power-on initialisation: initialise the floppy
   interface earlier, start on cylinder 0, and don't trigger a spurious
   step command

** v0.4.3a - 13 August 2017
 - Fix DSKCHG handling. Should make disk insertion more reliable,
   especially on Amiga with noclick patch.

** v0.4.2a - 11 August 2017
 - More efficient I2C handling for OLED and fix synch during flash
   update process.

** v0.4.1a - 11 August 2017
 - Improve I2C robustness

** v0.4.0a - 10 August 2017
** 128x32 I2C OLED Display support
 - Support for 0.91" I2C OLED (128x32, SSD1306 controller).
 - Various optimisations and bug fixes.

-------------------------------------------------------------------------

** v0.3.2a - 7 August 2017
 - Fix buffer overrun in HFE image handler when cannot read data from
   USB stick fast enough.
 - Update the Amiga AUTOBOOT.HFE with latest changes from upstream,
   and bump version number.

** v0.3.1a - 7 August 2017
 - Fix buffer overflow when copying long filenames in no-config mode.

** v0.3.0a - 6 August 2017
** Config-less & indexed operation
 - Operate with no AUTOBOOT.HFE (requires HXCSDFE.CFG in 'indexed
   mode'): files must be called DSKA0000.HFE, DSKA0001.HFE, and so
   on. ADF images are also supported.
 - Operate with no HXCSDFE.CFG! Buttons will cycle through all valid
   images in the USB root folder.
 - Step-pulse speaker is supported on output JB. Recommend buffering
   through an NPN transistor unless using a piezo speaker (high
   resistance).
 - Long filenames scroll on the 1602 LCD
 - LCD backlight timer, scroll speed, and step speaker volume all
   configured via HXCSDFE.CFG (when available)
 - Hack workaround for X-Copy problems. Verified writes/copies are now
   reliable!

-------------------------------------------------------------------------

** v0.2.1a - 26 July 2017
** Fixes for LCD handling
 - More reliable startup
 - Fix crashes and deadlocks in operation
 - More efficient command transmission (one I2C transaction for
   successive commands)
 - Support 0x38-0x3F I2C addresses

** v0.2.a - 25 July 2017
** 1602 LCD + Drive Logic Fixes
 - 1602 LCD handling: Will recognise a 1602 LCD with "I2C backpack" as
   used (and connected) for the usual "HxC LCD mod". Does not yet
   scroll long filenames, this will be added shortly.
 - Drive Logic: Will now play nicely in multi-drive systems and make
   AmigaDOS much less confused (no more DF1-3:BAD type messages!)
 - The bootloader is also modified to talk to the 1602 LCD: if you
   want this feature then you must also update the bootloader by doing
   a full serial or USB/DFU flash of the main HEX file.

-------------------------------------------------------------------------

** v0.1a - 21 July 2017
** Initial release
 - Works only as sole drive in a host system (eg disconnect external
   drives!)