I found the following instructions for key remapping with my comcast remote here:

http://en.wikibooks.org/wiki/How_to_use_a_Motorola_DVR/Programming_the_Remote

If I understand correctly, assuming I know the the code for a command that I want to program (a number from 00000 to 00255), I should be able to program the remote to send the command. However, I am a little unclear on the instructions. They are copied here below with my comments in < >.

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Remap a Key

This is the general procedure for remapping. Several common mapping options specific to the Motorola DVR are listed below.

1. (Option) Press and release the device key to make it the default.

< What does "default" refer to here? The device? The key itself? >

2. Press and hold the "Setup" button until a device key blinks twice.
3. Type in the code 994. A device key will blink twice.
4. (Option) Press and release the device key for the source device.

< What does "source device" mean? Why does it matter? Since remotes are not fundamentally 2-way, I'm not sure what this means >

5. Press the key to get the code from. This can be:
1. Another button with an existing code
2. Press and release "Setup", then type in a 3- or 5-digit code. The code is called an 'Extended Function Code' (EFC). Most of the silver remotes use 5-digit codes. Most others use 3-digits. In most cases, you just add '00' to the front of the 3-digit code to get a 5-digit code (00173 = 173).

< What if I have 2 devices which each respond to the same code but map it to a different function? Is each command sent by the remote prefaced by some kind of device ID which tells the destination device to listen? >

6. (Option) Press and release the device key for the destination device.

< Again, I don't understand the semantics. >

7. (Option) Press and release "Setup" to create a shifted key.
8. Press and release the button you want to put the code on.

< My hope is that I can remap a key when the remote is in TV mode, but retain that button's original behavior when the remote is in CABLE mode. Is this the case? As it is, when the remote is in TV mode, only a subset of the buttons control TV functions (volume, power, etc.) and the TV button lights up when these buttons are pressed. However, other buttons still control cable box functions and the CABLE button lights up accordingly. >

9. If the remap is successful, a device key will blink twice.

In general, I think it would help my understanding to learn more of the fundamentals of how these protocols work, but I have yet to find a resource on the web that lays this out.

1. (Option) Press and release the device key to make it the default.

< What does "default" refer to here? The device? The key itself? >
Default here just means being in the mode to control the device, as in "CABLE", "TV", or "AUX"


2. Press and hold the "Setup" button until a device key blinks twice.
3. Type in the code 994. A device key will blink twice.
4. (Option) Press and release the device key for the source device.

< What does "source device" mean? Why does it matter? Since remotes are not fundamentally 2-way, I'm not sure what this means >
These steps are for what UEI refers to as Keymoves. You are moving a functions defined in one key in a mode (the source), to another key in another mode (the destination). For example, you can move a function like ASPECT from the TV mode to a key (like the "HD/ZOOM") key in CABLE mode so that you can press the "HD/ZOOM" in CABLE mode to access the function on the TV without having to change to TV mode first. You can also use the keymove functions to add new functions if you know the EFC of the function. In that case, usually (not always), the source and the destination mode will be the same, and you can skip those steps.

5. Press the key to get the code from. This can be:
1. Another button with an existing code
2. Press and release "Setup", then type in a 3- or 5-digit code. The code is called an 'Extended Function Code' (EFC). Most of the silver remotes use 5-digit codes. Most others use 3-digits. In most cases, you just add '00' to the front of the 3-digit code to get a 5-digit code (00173 = 173).

< What if I have 2 devices which each respond to the same code but map it to a different function? Is each command sent by the remote prefaced by some kind of device ID which tells the destination device to listen? >
No, there is a device ID along with the ir protocol that each device uses, but that's part of the setup code, so if two devices uses the same setup code, that means they both have the same ir protocol and device ID. Some devices can be changed to use a different set of codes, but most likely, the Comcast remote only has the primary set. There is a way to add upgrades to the Comcast remote; more on that later.


6. (Option) Press and release the device key for the destination device.

< Again, I don't understand the semantics. >
See above on source. The destination is the mode you want to move the function from the source to.


7. (Option) Press and release "Setup" to create a shifted key.
8. Press and release the button you want to put the code on.

< My hope is that I can remap a key when the remote is in TV mode, but retain that button's original behavior when the remote is in CABLE mode. Is this the case? As it is, when the remote is in TV mode, only a subset of the buttons control TV functions (volume, power, etc.) and the TV button lights up when these buttons are pressed. However, other buttons still control cable box functions and the CABLE button lights up accordingly. >
There's actually two issues here. One is that if you found a setup code for your TV which has some of the functions, but not all, there is a way to add additional functions using EFC.

The second issue is that by default, the Channel lock function and the Volume lock functions are turned on with these remote. Channel lock sets the remote to alway use the functions of the CABLE mode for channel up and down, the number keys, and couple of other keys, no matter what mode you were on when you press those keys. Volume lock is the same for the volume up and down and the mute key, except it is set to TV mode by default. You can turn that off, or change the mode it should be set to (for example AUX for volume if you have AV receiver set to AUX).

In general, I think it would help my understanding to learn more of the fundamentals of how these protocols work, but I have yet to find a resource on the web that lays this out.
A better resource for learning about reprogramming the Comcast remote, and other remotes made by UEI is here:
http://www.hifi-remote.com
Check out the forum for more info. You can also find there, a way to make (or buy) a cable to connect the remote to a PC to reprogram key maps easier, add upgrades to control devices not built in, and add new functions. The Comcast remote is what is referred to in that site as either JP1.2 or JP1.3 remote, depending on how new yours is.

In all the years I've had a Motorola DVR, I didn't know the silver remote was made by UEI. :mad:So instead of programming the remote that came with the DVR, I bought a UEI 6131 and programmed that instead! Oh well, the Comcast remote only controls 3 devices anyway.

For example, you can move a function like ASPECT from the TV mode to a key (like the "HD/ZOOM") key in CABLE mode so that you can press the "HD/ZOOM" in CABLE mode to access the function on the TV without having to change to TV mode first.

I have been searching for a while on this...

This is exactly what I want to do for mine - I have a Sharp LC46D64U, whoose remote has a key on it for View Mode that cycles through 4 options. How can I re-map this function to the ZOOM key on the Comcast silver remote?

I have a Sharp LC46D64U, whoose remote has a key on it for View Mode that cycles through 4 options. How can I re-map this function to the ZOOM key on the Comcast silver remote?
Assuming you are using setup code TV/0093 for controlling the TV with the Comcast remote, try this:
1 Press and release TV
2 Press and hold SETUP until the remote blinks twice
3 Type 9 9 4
4 Press and release SETUP
5 Type 0 0 2 3 4
6 Press and release CABLE
7 Press and release HD/ZOOM

The remote should blink twice. If you are using a diffeent setup code, post what it is. The advanced code in step 5 might be different.

Works perfectly - Where did you find that sharp code? I looked for days - nothing here:

http://www.hifi-remote.com/cgi-bin2/ueic.cgi?TV_0093

You are good at this! Thanks so much!