What I am about to tell you is clearly documented in the Readme.txt that is included in the extender's .zip file. Here's the relevant text:
The first thing you need to understand is that the device keys have no special meaning. They are not in any way associated with the devices of the same name. However, to simplify things, the extender installation process assigns macros to the device keys to make them behave like the device keys in the unextended remote.DEVICE SELECTION:
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There is no normal device selection. There is no VPT. There is no
Transport Punch Through. There is no Home Theater Mode.
Instead there is a device selection mechanism by key set that has a
superset of the power of all the above; But you must define macros to use
and customize it.
The device keys have no built in meaning. You must define macros to
have any device selection at all.
There are 33 commands that can be used in macros to control device
selection. Each command specifies the key set and the Device Index that will
be used for keys in that set. For example V_TV says the TV device will be
used for keys in the "Volume" set.
There are 4 Key sets: Volume, Transport, Other and Temporary(X).
There are 8 Device Indexes: SAT, TV, PVR, VCR, DVD, AUD, DEV7 and
DEV8. There is one additional command X_Cancel.
To achieve simple device selection (no VPT, TPT or HT) you would put a 3
command macro on each device key, for example the TV device key would have
the macro:
V_TV; T_TV; O_TV
The 6131 has only 6 device keys; But the extender uses 8 device indexes.
You can use any keys you want for the device selection macros (and you can use
device keys for other purposes).
To achieve VPT, replace the V_ command within the macro for each device
that should have VPT enabled with the command from the device to which VPT
should be set. For example, to enable TV VPT on your VCR, the VCR key
macro might be:
V_TV; T_VCR; O_VCR
If you want full VPT (same V_ selection in all device selection macros) you
can save some macro memory by omitting all the V_ commands. You can set the
initial V device using IR. That remains as the V device as long as no V_
commands specify a different V_ device.
To achieve crude TPT (such as most of the UEIC remotes) replace the T_
command within the macro for each device that should have TPT enabled with
T_VCR. For example, your TV key macro might be:
V_TV; T_VCR; O_TV
To achieve dynamic TPT (similar to the URC7800). Omit the T_ command from
the macro for each non Transport device and include it in the macro for each
transport device (VCR, DVD etc.). When you select a non transport device,
the T keys will all remain associated with whatever transport device was
most recently selected.
Shifted keys all go into the key set containing their unshifted
counterpart. For example SHIFT-Stop is in the T set. Phantom keys are in
the O set. Device keys are in the O set; But most people will put macros
on device keys. If a key is a macro, it doesn't matter which set it is in.
The set only matters for KeyMoves and for keys defined by setup code.
Temporary Device Selection:
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Within a macro, you often want to issue a key to a specific device
regardless of the previous device selection and without disturbing that
previous device selection. You use X_ commands to do that. For example,
the sequence
X_TV; 0; 3
in a macro would send the 0 and 3 keys to the TV regardless of the previous
device selection.
The X_ selection is automatically canceled when the outermost macro (see
nested macros) completes. If the above example were intended for use as a
top level macro, there would be no need for it to explicitly cancel its X_
command. If the above example were in a general purpose macro that might
be called by other macros, you probably should change it to:
X_TV; 0; 3; X_Cancel
While an X_ command is active, it applies to all keys. The usual division
into Volume, Transport and Other doesn't apply.
The extender completely changes the way device selection works. In fact, there is no device selection. There is keyset selection. All the keys on the remote are divided into sets. There is a set for transport control (T), another set for volume (V), and a set for all others (0). There are also special virtual keys (they don't physically exist on the remote (like phantom keys), and you can't change what they do by assigning keymoves or macros to them) that are used for controlling which keyset is active at any time. Read the text above.
Edit the macro that is on the VCR button, adding the key presses you need to select the proper input and turn the VCR on.
