Simultaneous RCA video and HDMI output?

[PappyGoodwill]

Just got all my parts together and got my Pi functional today (Ordered June 28, arrived Oct 22)
I'm using the RCA video output while setting up HDMI. Will they both work at the same time?
As in: change something while using video and then switch monitor to HDMI to see if it worked.
Or will I have to unplug the video cable?

[piglet]

No, it's one or the other.

For HDMI to be selected by the Pi at boot time it either has to be forced in the configuration or the HDMI has to be connected and selected on the (switched on) monitor.

[PappyGoodwill]

Okay. Tried unplugging RCA, turned on monitor and set to HDMI input. Nothing.

Path is /boot/config.txt ?right location?

[itimpi]

Okay. Tried unplugging RCA, turned on monitor and set to HDMI input. Nothing.

Path is /boot/config.txt ?right location?

I assume you rebooted your Pi? The HDMI is only auto-detected at boot time.

[PappyGoodwill]

Yes, rebooted.

[piglet]

Next thing to try is hdmi_force_hotplug=1

See http://elinux.org/RPi_config.txt

[PappyGoodwill]

Okay tried "hdmi_force_hotplug=1" no luck.
Still no HDMI output. Here's all the specs I can find on my monitor:
Polaroid TLA-01511C ( "junk" has applied in more than one review)
Display Screen Size 15.0 in.
Display Type LCD
Resolution 1280x768 or 1440 x 900 (it varies with spec source)
Display Capability 480i, 480p, 720p, 1080i
Contrast Ratio 400:1
Aspect Ratio 16:9 or 16:10 (also varies with source)
Brightness 250 cd/m²
Response Time 16 ms
Comb Filter 3D
Analog Format NTSC, ATSC
Screen Refresh Rate 60Hz
Signal Compatibility 720p

Here's some of the settings in the samle config.txt file.
HDMI_CEA_480p60_2x = 14,
HDMI_CEA_480p60_2xH = 15,
HDMI_CEA_1080p60 = 16,
HDMI_CEA_576p50 = 17,
HDMI_CEA_576p50H = 18,
HDMI_CEA_720p50 = 19,
HDMI_CEA_1080i50 = 20,
HDMI_CEA_576i50 = 21,
HDMI_CEA_576i50H = 22,
HDMI_CEA_288p50 = 23,

There doesn't appear to be a consistant format.
There's 480p60_2xH = 15 and then 1080p60 = 16
???????????

[PappyGoodwill]

HDMI rule #1. Known good cable and NOT cheap TV. Saves a lot of heartburn and harsh language

[miguelito]

this worked for me -
hdmi_group=1
hdmi_mode=4

i found the modes using this tip from http://elinux.org/RPiconfig:

"Your HDMI monitor may support only a limited set of formats. To find out which formats are supported, use the following method.
Set the output format to VGA 60 Hz (hdmi_group=1 hdmi_mode=1) and boot up the Raspberry Pi
Enter the following command to give a list of CEA supported modes

/opt/vc/bin/tvservice -m CEA

Enter the following command to give a list of DMT supported modes

/opt/vc/bin/tvservice -m DMT"