Author Topic: Rpi can now possibly do 240p over composite!  (Read 10827 times)

keilmillerjr

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Rpi can now possibly do 240p over composite!
« on: March 01, 2017, 04:25:26 AM »
Big news I'd like to share. Doesn't really fit in any particular category here. But it might influence the amount of rpi users here.

I have a raspberry pi 2  that I quit working on once I learned that it couldn't do 240p over composite. There is a limitation put in place by the firmware. Some one yesterday came out with a test firmware allowing 240p and another user tested it and said it worked! This is huge for the retro community! I might order a pi3 and the composite dongle to try it out.

https://github.com/raspberrypi/firmware/issues/683#issuecomment-283179792

Quote
I have a test firmware here:
https://drive.google.com/uc?id=0B-6zmEDJwxZEME9lSEFZRmQ5RGs&export=download
Can you set (in config.txt):
sdtv_progressive_scan=1
and report back.
We have a progressive scan bit in the VEC (composite) register set.
We've tested that before and it wasn't sufficient. I've also tried disabling the interlaced signal that gets set. I'm not sure if it does the right thing (my composite TV's quality is a bit too low to tell).

Quote
popcornmix:
You're amazing! I just bought an old SOny Trinitron CRT that I'm planning on RGB modding and putting into an arcade cabinet. I'm still waiting on a Gert's VGA adapter though, so until then I've been playing around with composite 480i... which looks like a total flickering mess! I happened to check the thread today and saw your new firmware, so I just briefly tested it out.

It's such a huge improvement running this monitor over 240p. No more flickering, just beautiful stable scanlines. Everything seemed to be solid for the few minutes I played around with it. The only thing I noticed was that my picture was noticeably warped and slightly titled near the edges of the screen. It could just be my TV, since it's opened up right now, but I didn't notice it when I was running 480i. Could be an issue with the sync over composite... not sure. I'll have to do a better comparison with 240p vs. 480i on the set tomorrow. (There was also a high-pitched whine from the speakers, but I'm guess that's just because the TV's guts are exposed right now)

nitrogen_widget

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Re: Rpi can now possibly do 240p over composite!
« Reply #1 on: March 06, 2017, 08:22:34 AM »
Crap.
There goes my plans to clean out the basement tonight.

I actually have an RPI3 hooked up to a crappy lcd TV with the composite cable along with some 20" TV's in the basement.
Guess i'll install diet-pi and give this a shot tonight.
Sounds like advanced mame and mess is the way to go?

Bought a dead SNES and Genesis off ebay and planned to toss my CHIP computers in them and use 720p over composite for one of my many CRT's for a game room but......if this works on RPI.

wonder if a pi zero will work?
I have one but i don't think i can put my hand on all the annoying min-to normal sized adapters you need to interface with it.

nitrogen_widget

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Re: Rpi can now possibly do 240p over composite!
« Reply #2 on: March 07, 2017, 07:25:34 PM »
seems to work.
Zero flicker over composite on a thrift store 20" flat tube emerson TV.

This is advance mame 3 running on a rpi3 via command prompt.
will try NES/SNES/genesys emulators tomorrow.


keilmillerjr

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Re: Rpi can now possibly do 240p over composite!
« Reply #3 on: March 08, 2017, 02:58:13 PM »
@nitrogen_widget Nice! My results were similar. I am using lakka at the moment. I would look into possibly creating a custom image with attract mode and a current version of mame, but have no idea how I’d handle controllers.

nitrogen_widget

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Re: Rpi can now possibly do 240p over composite!
« Reply #4 on: March 08, 2017, 11:37:33 PM »
I think once you install the blob it won't do anything different until you set sdtv=16.
Should work on any raspbian based os.

keilmillerjr

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Re: Rpi can now possibly do 240p over composite!
« Reply #5 on: March 09, 2017, 07:29:11 AM »
I think once you install the blob it won't do anything different until you set sdtv=16.
Should work on any raspbian based os.
I have lakka 2.0 rc2. I downloaded the latest firmware from here and copied the following files to the lakka boot partition.

  • bootcode.bin
  • fixup.dat
  • fixup_cd.dat
  • fixup_db.dat
  • fixup_x.dat
  • start.elf
  • start_cd.elf
  • start_db.elf
  • start_x.elf

Then I edited config.txt with the following options and my notes.

Code: [Select]
################################################################################
# My configuration for composite out.
################################################################################

hdmi_ignore_hotplug=1 # force composite out
sdtv_mode=16 # 16 = progressive NTSC, 18 = progressive PAL
sdtv_aspect=1 # 1 = 4:3, 2 = 4:9, 3 = 16:9

The following was already commented out in config.txt.

Code: [Select]
# Force HDMI even if unplugged or powered off
# hdmi_force_hotplug=1

nitrogen_widget

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Re: Rpi can now possibly do 240p over composite!
« Reply #6 on: March 09, 2017, 08:28:49 AM »
What model flat screen do you have?
My emerson has some shadowing on berzerk.

I have a phillips and daewoo with component in that seem higher quality so i'll try those just to see but i plan to use vga to component 240p for those anyway.

Need to find a curved 19" TV.
thift store didn't have any.

few months back they had a pile for 5$ and my friends who were moving were dumping them at the curb.
I didn't want them because of composite only in and it gave me a flickering headache with standard 640x480 res.
so it figures i can't find any now. lol

keilmillerjr

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Re: Rpi can now possibly do 240p over composite!
« Reply #7 on: March 09, 2017, 02:45:59 PM »
What model flat screen do you have?
My emerson has some shadowing on berzerk.

I have a phillips and daewoo with component in that seem higher quality so i'll try those just to see but i plan to use vga to component 240p for those anyway.

Need to find a curved 19" TV.
thift store didn't have any.

few months back they had a pile for 5$ and my friends who were moving were dumping them at the curb.
I didn't want them because of composite only in and it gave me a flickering headache with standard 640x480 res.
so it figures i can't find any now. lol

I don’t have a flat screen. Its a 27“ sony trinitron KV-27TS36 with curved screen. Same model I remember my parents buying new back in 1993 at circuit city and I loved it. The only issue I am having is that its geometry needs fixing. Its not noticeable with watching tv, but noticeable with games or things with menus. I guess its a bitch to adjust on these.

Why do you plan on going via to composite? Any benefit?

Try craigslist for a crt. I see people giving them away all the time on there. Many thrift stores will not carry them anymore. Its a shame. :(

nitrogen_widget

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Re: Rpi can now possibly do 240p over composite!
« Reply #8 on: March 09, 2017, 07:23:05 PM »
What model flat screen do you have?
My emerson has some shadowing on berzerk.

I have a phillips and daewoo with component in that seem higher quality so i'll try those just to see but i plan to use vga to component 240p for those anyway.

Need to find a curved 19" TV.
thift store didn't have any.

few months back they had a pile for 5$ and my friends who were moving were dumping them at the curb.
I didn't want them because of composite only in and it gave me a flickering headache with standard 640x480 res.
so it figures i can't find any now. lol

I don’t have a flat screen. Its a 27“ sony trinitron KV-27TS36 with curved screen. Same model I remember my parents buying new back in 1993 at circuit city and I loved it. The only issue I am having is that its geometry needs fixing. Its not noticeable with watching tv, but noticeable with games or things with menus. I guess its a bitch to adjust on these.

Why do you plan on going via to composite? Any benefit?

Try craigslist for a crt. I see people giving them away all the time on there. Many thrift stores will not carry them anymore. Its a shame. :(

You need the remote and access to the service menu.
The emerson TV's i got with only composite in have geometry issues but i'll deal with it for console stuff because they were basically free.
my plan before this happened was to go from vga to YPbPr since i have the stuff to make the cable and the components to do the synching and i think it is going to give me a close to vga quality image.

but may not even need to since this honestly does look real good.

nitrogen_widget

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Re: Rpi can now possibly do 240p over composite!
« Reply #9 on: March 10, 2017, 04:43:13 AM »
This will be somewhat useful.
http://www.askvg.com/secret-service-codes-for-sony-and-lg-tv/

then find some CRT calibration images on the net.