diff --git a/doc/source/_static/examples.tgz b/doc/source/_static/examples.tgz
index f668e09c8..e933d5993 100644
Binary files a/doc/source/_static/examples.tgz and b/doc/source/_static/examples.tgz differ
diff --git a/doc/source/_static/examples.zip b/doc/source/_static/examples.zip
index 488f958d2..f8fb534a8 100644
Binary files a/doc/source/_static/examples.zip and b/doc/source/_static/examples.zip differ
diff --git a/doc/source/simulator.rst b/doc/source/simulator.rst
index fc60889e7..8569618e4 100644
--- a/doc/source/simulator.rst
+++ b/doc/source/simulator.rst
@@ -2,6 +2,8 @@ Simulator
 =========
 
 **WORK IN PROGRESS, do NOT use**
+Will be fully released in v4.0.0, until then please use
+:ref:`Simulator (3.x)`
 
 The simulator is a full fledged modbus server/simulator.
 
diff --git a/doc/source/upgrade_40.rst b/doc/source/upgrade_40.rst
index 48ea5a33c..4885b8361 100644
--- a/doc/source/upgrade_40.rst
+++ b/doc/source/upgrade_40.rst
@@ -4,4 +4,120 @@ Pymodbus 4.0 upgrade procedure
 Pymodbus 4.0 contains a number of incompatibilities with Pymodbus 3.x, however
 most of these are simple edits.
 
+Convert to SimData/SimDevice
+-----------------------------
+The old datastores:
+
+- ModbusSequentialDataBlock,
+- ModbusSparseDataBlock,
+- ModbusSimulatorContext
+
+are due to be removed in v4.0.0, starting with v3.13.0 the internal
+functionality are replaced by SimData/SimDevice.
+
+However there is a simple path to upgrade:
+
+ModbusSequentialDataBlock
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This datastore makes sequential registers, corresponding to old style devices.
+
+Example:
+.. code-block::
+    dev = ModbusDeviceContext(
+                co=ModbusSequentialDataBlock(0x01, 15),
+                di=ModbusSequentialDataBlock(0x01, [16]),
+                hr=ModbusSequentialDataBlock(0x01, [17]),
+                ir=ModbusSequentialDataBlock(0x01, [18])
+    )
+    server_context = ModbusServerContext(
+                        devices={1: dev,
+                                 0: dev
+                                })
+    await StartAsync**Server(context=server_context)
+
+Device_id = 0 is at "catch-all", that handles all devices not defined.
+
+This is very easily converted to SimData/SimDevice
+
+.. code-block::
+    from pymodbus.simulator import SimData, SimDevice, DataType
+
+    devices = [SimDevice(1, simdata=(
+                        SimData(0x01, values=15, datatype=DataType.REGISTERS),
+                        SimData(0x01, values=[17], datatype=DataType.REGISTERS),
+                        SimData(0x01, values=[17], datatype=DataType.REGISTERS),
+                        SimData(0x01, values=[17], datatype=DataType.REGISTERS)
+                    )
+                ),
+                SimDevice(1, simdata=(
+                        SimData(0x01, values=15, datatype=DataType.REGISTERS),
+                        SimData(0x01, values=[17], datatype=DataType.REGISTERS),
+                        SimData(0x01, values=[17], datatype=DataType.REGISTERS),
+                        SimData(0x01, values=[17], datatype=DataType.REGISTERS)
+                    )
+                )
+    ]
+    await StartAsync**Server(context=devices)
+
+
+ModbusSparseDataBlock
+^^^^^^^^^^^^^^^^^^^^^
+
+This datastore makes registers, with missing registers.
+
+Example:
+.. code-block::
+
+    dev = ModbusDeviceContext(
+                co=ModbusSparseDataBlock([1, 2, 3]),
+                di=ModbusSequentialDataBlock({
+                    1: 6720,
+                    30: 130
+                }),
+                hr=ModbusSparseDataBlock([4, 5, 6]),
+                ir=ModbusSparseDataBlock([7, 8, 9])
+    )
+    server_context = ModbusServerContext(
+                        devices={1: dev,
+                                 0: dev
+                                })
+    await StartAsync**Server(context=server_context)
+
+Device_id = 0 is at "catch-all", that handles all devices not defined.
+
+This is very easily converted to SimData/SimDevice
+
+.. code-block::
+    from pymodbus.simulator import SimData, SimDevice, DataType
+
+    devices = [SimDevice(1, simdata=(
+                        SimData(1, values=[1,2,3], datatype=DataType.REGISTERS),
+                        [SimData(1, values=6720, datatype=DataType.REGISTERS),
+                         SimData(30, values=130, datatype=DataType.REGISTERS)
+                        ],
+                        SimData(0x01, values=[4,5,6], datatype=DataType.REGISTERS),
+                        SimData(0x01, values=[7,8,9], datatype=DataType.REGISTERS)
+                    )
+                ),
+                SimDevice(1, simdata=(
+                        SimData(0x01, values=15, datatype=DataType.REGISTERS),
+                        SimData(0x01, values=[17], datatype=DataType.REGISTERS),
+                        SimData(0x01, values=[17], datatype=DataType.REGISTERS),
+                        SimData(0x01, values=[17], datatype=DataType.REGISTERS)
+                    )
+                )
+    ]
+    await StartAsync**Server(context=devices)
+
+ModbusSimulatorContext
+^^^^^^^^^^^^^^^^^^^^^^
+
+This datastore is a complicated setup with actions and typechecking.
+
+There are no very simple conversion, the configuration is grouped by datatypes then address.
+
+Basically convert each address set to a SimData with datatype= the type of the group.
+
+
 **This will be amended, whenever there API changes are merged**
\ No newline at end of file