v1.2.0

If you are upgrading: your sync tuning resets

Settings now live in isobar.ini instead of kgfax.ini. The first time you
run v1.2.0 your existing file is imported automatically — save folder, audio
device, window position, drum speed and sync window all carry over.

The Details… sync tuning does not carry over and goes back to defaults. That
is deliberate. Three of those settings turned out to have been read wrongly by
earlier Isobar versions, so an old file's numbers no longer mean what they say,
and there is no way to tell a file written by an old Isobar from one written by
KG-FAX itself. Rather than silently mis-tune the decoder, v1.2.0 starts clean.
If you had hand-tuned the Details dialog, set it again — the labels now say what
each value actually does.

Your kgfax.ini is never modified, so KG-FAX keeps working alongside Isobar.
.syn files are unaffected and still round-trip both ways.

New

• Recordings load at any sample rate. Previously only 22050 and 44100 Hz
  were accepted, which rejected most SDR recordings outright — HDSDR writes
  12 kHz, others 8 or 48 kHz. Anything from 6000 Hz up now works, resampled
  internally. 44100 Hz still takes its original exact path, so existing decodes
  are bit-for-bit unchanged.
• Details dialog says what it means. The sync settings were renamed from the
  original's cryptic ones (LReSycn, Sync2Thre, SyncWidth…) to
  Release after, Lock after, Max jump, Dark thresh. Two labels were also
  in the wrong places.

Fixed

• Auto ctl was 20× too twitchy. The start/stop tone detector treated its
  setting as milliseconds when it is a count of 100 ms blocks, so it fired after
  0.1 s of tone instead of 2 s. Noise could start or stop a reception.
• Two sync settings were mapped backwards, and a third was treated as a
  pulse width when it actually limits how far the sync position may move between
  lines. Sync tracking now behaves as intended; on a weak off-air recording this
  measured slightly better than before (1713 of 1851 lines locked, none lost).
• The Details dialog silently clamped one setting to a tenth of its valid range.

These came out of a full audit against a settings file generated by the original
KG-FAX, checked line by line against the original program itself.

Which file do I want?

You have	Download
Mac, M1 or later	Isobar-v1.2.0-macOS-AppleSilicon.dmg
Mac, Intel	Isobar-v1.2.0-macOS-Intel.dmg
Windows	Isobar-v1.2.0-windows.zip
Linux, PC	Isobar-v1.2.0-linux-x86_64.AppImage
Raspberry Pi / ARM Linux	Isobar-v1.2.0-linux-aarch64.AppImage

Everything needed is bundled — no FLTK or RtAudio install required.

First run

• macOS — right-click the app → Open the first time. It is ad-hoc
  signed, not notarized, so a double-click will be refused. Needs macOS 15+.
• Linux — chmod +x Isobar-v1.2.0-linux-*.AppImage then run it. Needs
  glibc 2.35+ (Debian 12 / Raspberry Pi OS bookworm and newer).
• Windows — unzip anywhere and run isobar-gui.exe. x64; Windows-on-ARM
  runs it under the system's own emulation.