artiq/RELEASE_NOTES.rst

.. Add new releases at the top to keep important stuff directly visible.

Release notes
=============

ARTIQ-8 (Unreleased)
--------------------

Highlights:

* New hardware support:
   - Support for Shuttler, a 16-channel 125MSPS DAC card intended for ion transport.
     Waveform generator and user API are similar to the NIST PDQ.
   - Implemented Phaser-servo. This requires recent gateware on Phaser.
   - Almazny v1.2 with finer RF switch control.
   - Metlino and Sayma support has been dropped due to complications with synchronous RTIO clocking.
   - More user LEDs are exposed to RTIO on Kasli.
   - Implemented Phaser-MIQRO support. This requires the proprietary Phaser MIQRO gateware
     variant from QUARTIQ.
   - Sampler: fixed ADC MU to Volt conversion factor for Sampler v2.2+.
     For earlier hardware versions, specify the hardware version in the device
     database file (e.g. ``"hw_rev": "v2.1"``) to use the correct conversion factor.
* Support for distributed DMA, where DMA is run directly on satellites for corresponding
  RTIO events, increasing bandwidth in scenarios with heavy satellite usage.
* Support for subkernels, where kernels are run on satellite device CPUs to offload some
  of the processing and RTIO operations.
* CPU (on softcore platforms) and AXI bus (on Zynq) are now clocked synchronously with the RTIO
  clock, to facilitate implementation of local processing on DRTIO satellites, and to slightly
  reduce RTIO latency.
* Support for DRTIO-over-EEM, used with Shuttler.
* Added channel names to RTIO error messages.
* GUI:
   - Implemented Applet Request Interfaces which allow applets to modify datasets and set the
     current values of widgets in the dashboard's experiment windows.
   - Implemented a new EntryArea widget which allows argument entry widgets to be used in applets.
   - The "Close all applets" command (shortcut: Ctrl-Alt-W) now ignores docked applets,
     making it a convenient way to clean up after exploratory work without destroying a
     carefully arranged default workspace.
   - Hotkeys now organize experiment windows in the order they were last interacted with:
      + CTRL+SHIFT+T tiles experiment windows
      + CTRL+SHIFT+C cascades experiment windows
   - By enabling the ``quickstyle`` option, ``EnumerationValue`` entry widgets can now alternatively display 
     its choices as buttons that submit the experiment on click.
* Datasets can now be associated with units and scale factors, and displayed accordingly in the dashboard
  including applets, like widgets such as ``NumberValue`` already did in earlier ARTIQ versions.
* Experiments can now request arguments interactively from the user at any time.
* Persistent datasets are now stored in a LMDB database for improved performance.
* Python's built-in types (such as ``float``, or ``List[...]``) can now be used in type annotations on
  kernel functions.
* Full Python 3.11 support.
* MSYS2 packaging for Windows, which replaces Conda. Conda packages are still available to
  support legacy installations, but may be removed in a future release.
* Experiments can now be submitted with revisions set to a branch / tag name instead of only git hashes.
* Grabber image input now has an optional timeout.

Breaking changes:

* ``SimpleApplet`` now calls widget constructors with an additional ``ctl`` parameter for control
  operations, which includes dataset operations. It can be ignored if not needed. For an example usage,
  refer to the ``big_number.py`` applet.
* ``SimpleApplet`` and ``TitleApplet`` now call ``data_changed`` with additional parameters. Derived applets
  should change the function signature as below:

::

  # SimpleApplet
  def data_changed(self, value, metadata, persist, mods)
  # SimpleApplet (old version)
  def data_changed(self, data, mods)
  # TitleApplet
  def data_changed(self, value, metadata, persist, mods, title)
  # TitleApplet (old version)
  def data_changed(self, data, mods, title)

Accesses to the data argument should be replaced as below:

::

  data[key][0] ==> persist[key]
  data[key][1] ==> value[key]

* The ``ndecimals`` parameter in ``NumberValue`` and ``Scannable`` has been renamed to ``precision``. 
  Parameters after and including ``scale`` in both constructors are now keyword-only.
  Refer to the updated ``no_hardware/arguments_demo.py`` example for current usage.
* Almazny v1.2 is incompatible with the legacy versions and is the default.
  To use legacy versions, specify ``almazny_hw_rev`` in the JSON description.
* kasli_generic.py has been merged into kasli.py, and the demonstration designs without JSON descriptions
  have been removed. The base classes remain present in kasli.py to support third-party flows without
  JSON descriptions.
* Legacy PYON databases should be converted to LMDB with the script below:

::

  from sipyco import pyon
  import lmdb

  old = pyon.load_file("dataset_db.pyon")
  new = lmdb.open("dataset_db.mdb", subdir=False, map_size=2**30)
  with new.begin(write=True) as txn:
    for key, value in old.items():
      txn.put(key.encode(), pyon.encode((value, {})).encode())
  new.close()

* ``artiq.wavesynth`` has been removed.

ARTIQ-7
-------

Highlights:

* New hardware support:
   - Kasli-SoC, a new EEM carrier based on a Zynq SoC, enabling much faster kernel execution
     (see: https://arxiv.org/abs/2111.15290).
   - DRTIO support on Zynq-based devices (Kasli-SoC and ZC706).
   - DRTIO support on KC705.
   - HVAMP_8CH 8 channel HV amplifier for Fastino / Zotinos
   - Almazny mezzanine board for Mirny
   - Phaser: improved documentation, exposed the DAC coarse mixer and ``sif_sync``, exposed upconverter calibration
     and enabling/disabling of upconverter LO & RF outputs, added helpers to align Phaser updates to the
     RTIO timeline (``get_next_frame_mu()``).
   - Urukul: ``get()``, ``get_mu()``, ``get_att()``, and ``get_att_mu()`` functions added for AD9910 and AD9912.
* Softcore targets now use the RISC-V architecture (VexRiscv) instead of OR1K (mor1kx).
* Gateware FPU is supported on KC705 and Kasli 2.0.
* Faster compilation for large arrays/lists.
* Faster exception handling.
* Several exception handling bugs fixed.
* Support for a simpler shared library system with faster calls into the runtime. This is only used by the NAC3
  compiler (nac3ld) and improves RTIO output performance (test_pulse_rate) by 9-10%.
* Moninj improvements:
  - Urukul monitoring and frequency setting (through dashboard) is now supported.
  - Core device moninj is now proxied via the ``aqctl_moninj_proxy`` controller.
* The configuration entry ``rtio_clock`` supports multiple clocking settings, deprecating the usage
  of compile-time options.
* Added support for 100MHz RTIO clock in DRTIO.
* Previously detected RTIO async errors are reported to the host after each kernel terminates and a
  warning is logged. The warning is additional to the one already printed in the core device log
  immediately upon detection of the error.
* Extended Kasli gateware JSON description with configuration for SPI over DIO.
* TTL outputs can be now configured to work as a clock generator from the JSON.
* On Kasli, the number of FIFO lanes in the scalable events dispatcher (SED) can now be configured in
  the JSON.
* ``artiq_ddb_template`` generates edge-counter keys that start with the key of the corresponding
  TTL device (e.g. ``ttl_0_counter`` for the edge counter on TTL device ``ttl_0``).
* ``artiq_master`` now has an ``--experiment-subdir`` option to scan only a subdirectory of the
  repository when building the list of experiments.
* Experiments can now be submitted by-content.
* The master can now optionally log all experiments submitted into a CSV file.
* Removed worker DB warning for writing a dataset that is also in the archive.
* Experiments can now call ``scheduler.check_termination()`` to test if the user
  has requested graceful termination.
* ARTIQ command-line programs and controllers now exit cleanly on Ctrl-C.
* ``artiq_coremgmt reboot`` now reloads gateware as well, providing a more thorough and reliable
  device reset (7-series FPGAs only).
* Firmware and gateware can now be built on-demand on the M-Labs server using ``afws_client``
  (subscribers only). Self-compilation remains possible.
* Easier-to-use packaging via Nix Flakes.
* Python 3.10 support (experimental).

Breaking changes:

* Due to the new RISC-V CPU, the device database entry for the core device needs to be updated.
  The ``target`` parameter needs to be set to ``rv32ima`` for Kasli 1.x and to ``rv32g`` for all
  other boards. Freshly generated device database templates already contain this update.
* Updated Phaser-Upconverter default frequency 2.875 GHz. The new default uses the target PFD
  frequency of the hardware design.
* ``Phaser.init()`` now disables all Kasli-oscillators. This avoids full power RF output being
  generated for some configurations.
* Phaser: fixed coarse mixer frequency configuration
* Mirny: Added extra delays in ``ADF5356.sync()``. This avoids the need of an extra delay before
  calling ``ADF5356.init()``.
* The deprecated ``set_dataset(..., save=...)`` is no longer supported.
* The ``PCA9548`` I2C switch class was renamed to ``I2CSwitch``, to accommodate support for PCA9547,
  and possibly other switches in future. Readback has been removed, and now only one channel per
  switch is supported.


ARTIQ-6
-------

Highlights:

* New hardware support:
   - Phaser, a quad channel 1GS/s RF generator card with dual IQ upconverter and dual 5MS/s
     ADC and FPGA.
   - Zynq SoC core device (ZC706), enabling kernels to run on 1 GHz CPU core with a floating-point
     unit for faster computations. This currently requires an external
     repository (https://git.m-labs.hk/m-labs/artiq-zynq).
   - Mirny 4-channel wide-band PLL/VCO-based microwave frequency synthesiser
   - Fastino 32-channel, 3MS/s per channel, 16-bit DAC EEM
   - Kasli 2.0, an improved core device with 12 built-in EEM slots, faster FPGA, 4 SFPs, and
     high-precision clock recovery circuitry for DRTIO (to be supported in ARTIQ-7).
* ARTIQ Python (core device kernels):
   - Multidimensional arrays are now available on the core device, using NumPy syntax.
     Elementwise operations (e.g. ``+``, ``/``), matrix multiplication (``@``) and
     multidimensional indexing are supported; slices and views are not yet.
   - Trigonometric and other common math functions from NumPy are now available on the
     core device (e.g. ``numpy.sin``), both for scalar arguments and implicitly
     broadcast across multidimensional arrays.
   - Failed assertions now raise ``AssertionError``\ s instead of aborting kernel
     execution.
* Performance improvements:
   - SERDES TTL inputs can now detect edges on pulses that are shorter
     than the RTIO period (https://github.com/m-labs/artiq/issues/1432)
   - Improved performance for kernel RPC involving list and array.
* Coredevice SI to mu conversions now always return valid codes, or raise a ``ValueError``.
* Zotino now exposes  ``voltage_to_mu()``
* ``ad9910``: 
   - The maximum amplitude scale factor is now ``0x3fff`` (was ``0x3ffe`` before).
   - The default single-tone profile is now 7 (was 0).
   - Added option to ``set_mu()`` that affects the ASF, FTW and POW registers
     instead of the single-tone profile register.
* Mirny now supports HW revision independent, human readable ``clk_sel`` parameters:
  "XO", "SMA", and "MMCX". Passing an integer is backwards compatible.
* Dashboard:
   - Applets now restart if they are running and a ccb call changes their spec
   - A "Quick Open" dialog to open experiments by typing part of their name can
     be brought up Ctrl-P (Ctrl+Return to immediately submit the selected entry
     with the default arguments).
   - The Applets dock now has a context menu command to quickly close all open
     applets (shortcut: Ctrl-Alt-W).
* Experiment results are now always saved to HDF5, even if ``run()`` fails.
* Core device: ``panic_reset 1`` now correctly resets the kernel CPU as well if
  communication CPU panic occurs.
* NumberValue accepts a ``type`` parameter specifying the output as ``int`` or ``float``
* A parameter ``--identifier-str`` has been added to many targets to aid
  with reproducible builds.
* Python 3.7 support in Conda packages.
* `kasli_generic` JSON descriptions are now validated against a
  schema. Description defaults have moved from Python to the
  schema. Warns if ARTIQ version is too old.

Breaking changes:

* ``artiq_netboot`` has been moved to its own repository at
  https://git.m-labs.hk/m-labs/artiq-netboot
* Core device watchdogs have been removed.
* The ARTIQ compiler now implements arrays following NumPy semantics, rather than as a
  thin veneer around lists. Most prior use cases of NumPy arrays in kernels should work
  unchanged with the new implementation, but the behavior might differ slightly in some
  cases (for instance, non-rectangular arrays are not currently supported).
* ``quamash`` has been replaced with ``qasync``.
* Protocols are updated to use device endian.
* Analyzer dump format includes a byte for device endianness.
* To support variable numbers of Urukul cards in the future, the
  ``artiq.coredevice.suservo.SUServo`` constructor now accepts two device name lists,
  ``cpld_devices`` and ``dds_devices``, rather than four individual arguments.
* Experiment classes with underscore-prefixed names are now ignored when ``artiq_client``
  determines which experiment to submit (consistent with ``artiq_run``).

ARTIQ-5
-------

Highlights:

* Performance improvements:
   - Faster RTIO event submission (1.5x improvement in pulse rate test)
     See: https://github.com/m-labs/artiq/issues/636
   - Faster compilation times (3 seconds saved on kernel compilation time on a typical
     medium-size experiment)
     See: https://github.com/m-labs/artiq/commit/611bcc4db4ed604a32d9678623617cd50e968cbf
* Improved packaging and build system:
   - new continuous integration/delivery infrastructure based on Nix and Hydra,
     providing reproducibility, speed and independence.
   - rolling release process (https://github.com/m-labs/artiq/issues/1326).
   - firmware, gateware and device database templates are automatically built for all
     supported Kasli variants.
   - new JSON description format for generic Kasli systems.
   - Nix packages are now supported.
   - many Conda problems worked around.
   - controllers are now out-of-tree.
   - split packages that enable lightweight applications that communicate with ARTIQ,
     e.g. controllers running on non-x86 single-board computers.
* Improved Urukul support:
   - AD9910 RAM mode.
   - Configurable refclk divider and PLL bypass.
   - More reliable phase synchronization at high sample rates.
   - Synchronization calibration data can be read from EEPROM.
* A gateware-level input edge counter has been added, which offers higher
  throughput and increased flexibility over the usual TTL input PHYs where
  edge timestamps are not required. See ``artiq.coredevice.edge_counter`` for
  the core device driver and ``artiq.gateware.rtio.phy.edge_counter``/
  ``artiq.gateware.eem.DIO.add_std`` for the gateware components.
* With DRTIO, Siphaser uses a better calibration mechanism.
  See: https://github.com/m-labs/artiq/commit/cc58318500ecfa537abf24127f2c22e8fe66e0f8
* Schedule updates can be sent to influxdb (artiq_influxdb_schedule).
* Experiments can now programatically set their default pipeline, priority, and flush flag.
* List datasets can now be efficiently appended to from experiments using
  ``artiq.language.environment.HasEnvironment.append_to_dataset``.
* The core device now supports IPv6.
* To make development easier, the bootloader can receive firmware and secondary FPGA
  gateware from the network.
* Python 3.7 compatibility (Nix and source builds only, no Conda).
* Various other bugs from 4.0 fixed.
* Preliminary Sayma v2 and Metlino hardware support.

Breaking changes:

* The ``artiq.coredevice.ad9910.AD9910`` and
  ``artiq.coredevice.ad9914.AD9914`` phase reference timestamp parameters
  have been renamed to ``ref_time_mu`` for consistency, as they are in machine
  units.
* The controller manager now ignores device database entries without the
  ``command`` key set to facilitate sharing of devices between multiple
  masters.
* The meaning of the ``-d/--dir`` and ``--srcbuild`` options of ``artiq_flash``
  has changed.
* Controllers for third-party devices are now out-of-tree.
* ``aqctl_corelog`` now filters log messages below the ``WARNING`` level by default.
  This behavior can be changed using the ``-v`` and ``-q`` options like the other
  programs.
* On Kasli the firmware now starts with a unique default MAC address
  from EEPROM if `mac` is absent from the flash config.
* The ``-e/--experiment`` switch of ``artiq_run`` and ``artiq_compile``
  has been renamed ``-c/--class-name``.
* ``artiq_devtool`` has been removed.
* Much of ``artiq.protocols`` has been moved to a separate package ``sipyco``.
  ``artiq_rpctool`` has been renamed to ``sipyco_rpctool``.


ARTIQ-4
-------

4.0
***

* The ``artiq.coredevice.ttl`` drivers no longer track the timestamps of
  submitted events in software, requiring the user to explicitly specify the
  timeout for ``count()``/``timestamp_mu()``. Support for ``sync()`` has been dropped.

  Now that RTIO has gained DMA support, there is no longer a reliable way for
  the kernel CPU to track the individual events submitted on any one channel.
  Requiring the timeouts to be specified explicitly ensures consistent API
  behavior. To make this more convenient, the ``TTLInOut.gate_*()`` functions
  now return the cursor position at the end of the gate, e.g.::

    ttl_input.count(ttl_input.gate_rising(100 * us))

  In most situations – that is, unless the timeline cursor is rewound after the
  respective ``gate_*()`` call – simply passing ``now_mu()`` is also a valid
  upgrade path::

    ttl_input.count(now_mu())

  The latter might use up more timeline slack than necessary, though.

  In place of ``TTL(In)Out.sync``, the new ``Core.wait_until_mu()`` method can
  be used, which blocks execution until the hardware RTIO cursor reaches the
  given timestamp::

    ttl_output.pulse(10 * us)
    self.core.wait_until_mu(now_mu())
* RTIO outputs use a new architecture called Scalable Event Dispatcher (SED),
  which allows building systems with large number of RTIO channels more
  efficiently.
  From the user perspective, collision errors become asynchronous, and non-
  monotonic timestamps on any combination of channels are generally allowed
  (instead of producing sequence errors).
  RTIO inputs are not affected.
* The DDS channel number for the NIST CLOCK target has changed.
* The dashboard configuration files are now stored one-per-master, keyed by the
  server address argument and the notify port.
* The master now has a ``--name`` argument. If given, the dashboard is labelled
  with this name rather than the server address.
* ``artiq_flash`` targets Kasli by default. Use ``-t kc705`` to flash a KC705
  instead.
* ``artiq_flash -m/--adapter`` has been changed to ``artiq_flash -V/--variant``.
* The ``proxy`` action of ``artiq_flash`` is determined automatically and should
  not be specified manually anymore.
* ``kc705_dds`` has been renamed ``kc705``.
* The ``-H/--hw-adapter`` option of ``kc705`` has been renamed ``-V/--variant``.
* SPI masters have been switched from misoc-spi to misoc-spi2. This affects
  all out-of-tree RTIO core device drivers using those buses. See the various
  commits on e.g. the ``ad53xx`` driver for an example how to port from the old
  to the new bus.
* The ``ad5360`` coredevice driver has been renamed to ``ad53xx`` and the API
  has changed to better support Zotino.
* ``artiq.coredevice.dds`` has been renamed to ``artiq.coredevice.ad9914`` and
  simplified. DDS batch mode is no longer supported. The ``core_dds`` device
  is no longer necessary.
* The configuration entry ``startup_clock`` is renamed ``rtio_clock``. Switching
  clocks dynamically (i.e. without device restart) is no longer supported.
* ``set_dataset(..., save=True)`` has been renamed
  ``set_dataset(..., archive=True)``.
* On the AD9914 DDS, when switching to ``PHASE_MODE_CONTINUOUS`` from another mode,
  use the returned value of the last ``set_mu`` call as the phase offset for
  ``PHASE_MODE_CONTINUOUS`` to avoid a phase discontinuity. This is no longer done
  automatically. If one phase glitch when entering ``PHASE_MODE_CONTINUOUS`` is not
  an issue, this recommendation can be ignored.


ARTIQ-3
-------

3.7
***

No further notes.


3.6
***

No further notes.


3.5
***

No further notes.


3.4
***

No further notes.


3.3
***

No further notes.


3.2
***

* To accommodate larger runtimes, the flash layout as changed. As a result, the
  contents of the flash storage will be lost when upgrading. Set the values back
  (IP, MAC address, startup kernel, etc.) after the upgrade.


3.1
***

No further notes.


3.0
***

* The ``--embed`` option of applets is replaced with the environment variable
  ``ARTIQ_APPLET_EMBED``. The GUI sets this enviroment variable itself and the
  user simply needs to remove the ``--embed`` argument.
* ``EnvExperiment``'s ``prepare`` calls ``prepare`` for all its children.
* Dynamic ``__getattr__``'s returning RPC target methods are not supported anymore.
  Controller driver classes must define all their methods intended for RPC as
  members.
* Datasets requested by experiments are by default archived into their HDF5
  output. If this behavior is undesirable, turn it off by passing
  ``archive=False`` to ``get_dataset``.
* ``seconds_to_mu`` and ``mu_to_seconds`` have become methods of the core
  device driver (use e.g. ``self.core.seconds_to_mu()``).
* AD9858 DDSes and NIST QC1 hardware are no longer supported.
* The DDS class names and setup options have changed, this requires an update of
  the device database.
* ``int(a, width=b)`` has been removed. Use ``int32(a)`` and ``int64(a)``.
* The KC705 gateware target has been renamed ``kc705_dds``.
* ``artiq.coredevice.comm_tcp`` has been renamed ``artiq.coredevice.comm_kernel``,
  and ``Comm`` has been renamed ``CommKernel``.
* The "collision" and "busy" RTIO errors are reported through the log instead of
  raising exceptions.
* Results are still saved when ``analyze`` raises an exception.
* ``LinearScan`` and ``RandomScan`` have been consolidated into RangeScan.
* The Pipistrello is no longer supported. For a low-cost ARTIQ setup, use either
  ARTIQ 2.x with Pipistrello, or the future ARTIQ 4.x with Kasli. Note that the
  Pipistrello board has also been discontinued by the manufacturer but its design
  files are freely available.
* The device database is now generated by an executable Python script. To migrate
  an existing database, add ``device_db = `` at the beginning, and replace any PYON
  identifiers (``true``, ``null``, ...) with their Python equivalents
  (``True``, ``None`` ...).
* Controllers are now named ``aqctl_XXX`` instead of ``XXX_controller``.
* In the device database, the ``comm`` device has been folded into the ``core`` device.
  Move the "host" argument into the ``core`` device, and remove the ``comm`` device.
* The core device log now contains important information about events such as
  RTIO collisions. A new controller ``aqctl_corelog`` must be running to forward
  those logs to the master. See the example device databases to see how to
  instantiate this controller. Using ``artiq_session`` ensures that a controller
  manager is running simultaneously with the master.
* Experiments scheduled with the "flush pipeline" option now proceed when there
  are lower-priority experiments in the pipeline. Only experiments at the current
  (or higher) priority level are flushed.
* The PDQ(2/3) driver has been removed and is now being maintained out-of tree
  at https://github.com/m-labs/pdq. All SPI/USB driver layers, Mediator,
  CompoundPDQ and examples/documentation has been moved.
* The master now rotates log files at midnight, rather than based on log size.
* The results keys ``start_time`` and ``run_time`` are now stored as doubles of UNIX time,
  rather than ints. The file names are still based on local time.
* Packages are no longer available for 32-bit Windows.


ARTIQ-2
-------

2.5
***

No further notes.


2.4
***

No further notes.


2.3
***

* When using conda, add the conda-forge channel before installing ARTIQ.


2.2
***

No further notes.


2.1
***

No further notes.


2.0
***

No further notes.


2.0rc2
******

No further notes.


2.0rc1
******

* The format of the influxdb pattern file is simplified. The procedure to
  edit patterns is also changed to modifying the pattern file and calling:
  ``artiq_rpctool.py ::1 3248 call scan_patterns`` (or restarting the bridge)
  The patterns can be converted to the new format using this code snippet::

    from artiq.protocols import pyon
    patterns = pyon.load_file("influxdb_patterns.pyon")
    for p in patterns:
        print(p)

* The "GUI" has been renamed the "dashboard".
* When flashing NIST boards, use "-m nist_qcX" or "-m nist_clock" instead of
  just "-m qcX" or "-m clock" (#290).
* Applet command lines now use templates (e.g. $python) instead of formats
  (e.g. {python}).
* On Windows, GUI applications no longer open a console. For debugging
  purposes, the console messages can still be displayed by running the GUI
  applications this way::

    python3.5 -m artiq.frontend.artiq_browser
    python3.5 -m artiq.frontend.artiq_dashboard

  (you may need to replace python3.5 with python)
  Please always include the console output when reporting a GUI crash.
* The result folders are formatted "%Y-%m-%d/%H instead of "%Y-%m-%d/%H-%M".
  (i.e. grouping by day and then by hour, instead of by day and then by minute)
* The ``parent`` keyword argument of ``HasEnvironment`` (and ``EnvExperiment``)
  has been replaced. Pass the parent as first argument instead.
* During experiment examination (and a fortiori repository scan), the values of
  all arguments are set to ``None`` regardless of any default values supplied.
* In the dashboard's experiment windows, partial or full argument recomputation
  takes into account the repository revision field.
* By default, ``NumberValue`` and ``Scannable`` infer the scale from the unit
  for common units.
* By default, artiq_client keeps the current persist flag on the master.
* GUI state files for the browser and the dashboard are stores in "standard"
  locations for each operating system. Those are
  ``~/.config/artiq/2/artiq_*.pyon`` on Linux and
  ``C:\Users\<username>\AppData\Local\m-labs\artiq\2\artiq_*.pyon`` on
  Windows 7.
* The position of the time cursor is kept across experiments and RTIO resets
  are manual and explicit (inter-experiment seamless handover).
* All integers manipulated by kernels are numpy integers (numpy.int32,
  numpy.int64). If you pass an integer as a RPC argument, the target function
  receives a numpy type.


ARTIQ-1
-------

1.3
***

No further notes.


1.2
***

No further notes.


1.1
***

* TCA6424A.set converts the "outputs" value to little-endian before programming
  it into the registers.


1.0
***

No further notes.


1.0rc4
******

* setattr_argument and setattr_device add their key to kernel_invariants.


1.0rc3
******

* The HDF5 format has changed.

  * The datasets are located in the HDF5 subgroup ``datasets``.
  * Datasets are now stored without additional type conversions and annotations
    from ARTIQ, trusting that h5py maps and converts types between HDF5 and
    python/numpy "as expected".

* NumberValue now returns an integer if ``ndecimals`` = 0, ``scale`` = 1 and
  ``step`` is integer.


1.0rc2
******

* The CPU speed in the pipistrello gateware has been reduced from 83 1/3 MHz to
  75 MHz. This will reduce the achievable sustained pulse rate and latency
  accordingly. ISE was intermittently failing to meet timing (#341).
* set_dataset in broadcast mode no longer returns a Notifier. Mutating datasets
  should be done with mutate_dataset instead (#345).


1.0rc1
******

* Experiments (your code) should use ``from artiq.experiment import *``
  (and not ``from artiq import *`` as previously)
* Core device flash storage has moved due to increased runtime size.
  This requires reflashing the runtime and the flash storage filesystem image
  or erase and rewrite its entries.
* ``RTIOCollisionError`` has been renamed to ``RTIOCollision``
* the new API for DDS batches is::

    with self.core_dds.batch:
       ...

  with ``core_dds`` a device of type ``artiq.coredevice.dds.CoreDDS``.
  The dds_bus device should not be used anymore.
* LinearScan now supports scanning from high to low. Accordingly,
  its arguments ``min/max`` have been renamed to ``start/stop`` respectively.
  Same for RandomScan (even though there direction matters little).