Melodee 1.5.0-rc.3 reduces RAM, firmware size and dry-mixer CPU work, improves display transfers, and fixes metronome volume and FM6 SysEx reception.
It includes the automatic chords, controller profiles and other features in
RC2.
Stable 1.4.5 remains the default installer channel.
Memory and performance
- Recovers about 25 KiB of general audio working memory through shared FX
coefficients, exact FM6 ROM symmetry, smaller resident control code and reduced
stack reservations checked against linked call paths. - Compresses the resident-code load image in flash and expands the identical
instructions once at startup, before audio and the second core start.
The measured development image shrinks by about 35 KiB. The fixed-slot
installation package retains its usual size. - Avoids unused wet-return work and adds a centered-dry mixer path. The complete
four-track dry fixture uses 5.3% fewer host instructions, including 4.3%
from the second optimization pass. These are host measurements, not measured
FM-1 CPU percentages or deadline guarantees. - Preset saving avoids large whole-bank stack copies while retaining the same
serialized bytes, failure rollback, favorites, opaque records and migrations.
PUNCH history tradeoff
The optional PUNCH history now uses 32 KiB instead of 64 KiB while armed.
History lasts about 372 ms instead of 743 ms at 44.1 kHz. Replay spans cap at
348 ms and echo delays at 370 ms, so long beat divisions at slower tempos use a
shorter capture. All 27 choices, FREEZE and existing transitions remain available.
Engine stereo placement and rack reverb tank lengths are retained.
Bluetooth MIDI is not included. The BLE-only HCI specialization is a separate
experimental size probe; this RC does not establish that a BLE port fits.
Display and musical fixes
- Display updates send changed tiles through bounded DMA buffers, reducing
redundant transfers while preserving buffer ownership during drawing. - The metronome follows master volume, including silence at master zero.
- Extended DX7 voice dumps recover correctly in the FM6 SysEx receiver.
- The default MIDI-only preset is named MIDI Track.
- Restores the runnable nightly workflow so development builds no longer enter
a recursive scheduler wrapper.
Validation and hardware status
Blocking checks cover reference sound renders, mixer parity and CPU budgets,
FM6 lookup parity, storage migrations and every preset-write failure stage,
PUNCH capture wraps and transitions, dual-core/reference behavior, UI, MIDI,
USB, web installation and recovery. Independent boot-decoder fixtures include
malformed streams and exact expansion of the packaged resident-code image under
address/undefined-behavior sanitizers.
This candidate changes startup decompression and stack reservations. Their linked
bounds and recovery paths are checked automatically; cold/soft boot, physical
stack watermarks, sustained audio deadlines and device interoperability still
need hardware acceptance for this exact candidate. Automated checks do not
establish those measurements. RC1's project-format and migration limits continue
to apply.
Firmware and application binaries are built and attested by the reviewed
zvenson/fm1-build/.github/workflows/build.yml@v1 workflow. Downloads include native
UBOOT recovery tools for Windows x64, macOS Apple Silicon, macOS Intel and Linux
x64, licence notices, BUILD_INFO.json and SHA256SUMS. The release workflow
verifies attestations, application bytes and the complete recovery set before
publication. Verify the firmware with:
gh attestation verify melodee-1.5.0-rc.3.fwsc --repo keremimo/melodee \
--signer-workflow zvenson/fm1-build/.github/workflows/build.yml \
--source-ref refs/tags/v1.5.0-rc.3