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2nd or 3rd attempt to a rgb tv mod. Any advice wellcome.
abispac:
So i can say im almost done with this mode, i just cant figureout what im missing. I did everything exactly as the 8bit guy did, well, not the fancy conector, as i might add it later on. Hook my pc with my vga brekout cable, and bam, clear colors but bad sync
So i started emudrivers on my other tv (i had both monitors hooked, i always do that on crtdrivers) and dont matter what settings i choose, 15khz, 31khz o 60 khz, i cant get this thing to sync. i can still see that colors are gonna be good, i ust need a bit of help in here please. So so far, as the 8bit guy did, the rgb cables have the 75ohm resistors terminated to ground, all grounds go to ground, i get the 5v volts from the same place, and the sync i try to get it from the yellow rca entrance on the back of the tv. but no luck. Do i need to add a 75ohn resistor on the sync cable as well? or do i need to build the vga cable has he did on his second video? thanks for any help.
This is how far i got.
and a link to the second video where he builds the vga cable.
buttersoft:
You're saying this same video source, a PC or whatever it is, will show an image on your arcade monitor, but not on this TV, correct?
Are you getting composite sync directly from VGA pin 13 by turning on the option to in VMM/crt_emudriver? (You say you're trying to "get" sync from the yellow RCA socket on the TV, but i assume you're feeding sync into that.) If there are no components in the pin-13 composite sync line at present, try adding some - do not add a resistor to ground just yet. Putting a 1K pot in line and dialing it up from 0R is probably a place to start.
abispac:
--- Quote from: buttersoft on April 20, 2020, 12:00:48 am ---You're saying this same video source, a PC or whatever it is, will show an image on your arcade monitor, but not on this TV, correct?
--- End quote ---
Yes sir, all arcade monitors the image shows good quality and just fine.
--- Quote from: buttersoft on April 20, 2020, 12:00:48 am ---Are you getting composite sync directly from VGA pin 13 by turning on the option to in VMM/crt_emudriver? (You say you're trying to "get" sync from the yellow RCA socket on the TV, but i assume you're feeding sync into that.) If there are no components in the pin-13 composite sync line at present, try adding some - do not add a resistor to ground just yet. Putting a 1K pot in line and dialing it up from 0R is probably a place to start.
--- End quote ---
To be honest on arcade monitors i just put both sync cables together, 13 and 14, thats it, works just fine.and yes you are right, im trying to feed sync via the yellow rca socket and that dont work. i did try to turn on the sync option in vmm but i didnt read the part that i had to redo the modlines, so ill try again, but my card its a hd7000 and that option apears to be for hd5000 and lower. Anyway if i add a 1k pot, how would i go about doing that? Now i didnt saw the 8bit guy doing anything extra to get his tv in sync, unless im missing a detail.
The pots i have have tree legs, so i really apreciate if you elight me on how to do that part, thanks mr Buttersoft.
Oh and i forgot, using 15khz generic mode, should be ok right? I did try 31khz, mode, 15khz dual sync, 25khz, and some others, non seem to work for me.
PS: This is a picutre of the computer on a regular arcade monitor with a weiya chassis.
buttersoft:
VGA sync outputs at TTL levels = 5Vp-p. Try composite sync from VMM first. If that doesn't work, go back to separate H- and V-sync, then using a 480i mode that works on your arcade monitors, start with a 500R resistor and a 1k pot in each line, then merge and feed into the CRT where composite video would normally go in. Dial the pots around and see what happens.
abispac:
:laugh2: i should be ashamed of myself. Im not sure how the arcade monitors displayed and image, because my vga cable was a total mess. I notice it, because, the sync did not have an effect on the tv, it was like if i had nothing hooked up, there was no difference if i had the sync cable connected or disconnected, i took my multi-meter and started checking the pins, man what a mess, the sync cables where at the grounds and i was using one ground as v sync and a cable thats not even used as a h sync, so i redid my cable and will test it out again tomorrow. im pretty sure everything its gonna work out of the box this time. :laugh2:
Thanks to this tv now im gonna have a good working cable and i learn to double check that before i screw more monitors...
Ill post results later on.