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Ossc or XPC-4 use on BVM

Started by toyhopperhk, October 26, 2018, 09:04:38 pm

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toyhopperhk

Hello guys
I want X68000XVI use on Sony Crt Bvm -D24,
have two choice now, Ossc or XPC-4?
Thx

hyrulebr

Hi

I have a D20 and have this obssession: Fully use my X68000 with this monitor!   8)

Well, you can use the X68000 with just a "sync combiner" (e.g. any extron RGB interface) at 15khz directly without the need of a OSCC or XPC-4. Nice picture with bold scanlines.

But at 31khz the image is dark, greenish.

I tried to use more than 7 different models of Extron interfaces (580xi, 160xi, 130xi, 203rxi, 190, etc) and the Kenzei sync combiner (https://www.beharbros.com/kenzei). :-[

What worked:

A XPC-4 (using the device vga out at 480p). I don't know how much lag are involved but is very strange to use a digital equipment like that in a CRT monitor!   ::)
An Extron Emotia downscaling the 480p image to 240p. I liked it but needs to test with more games.

To test in future:

TV one corio2 (I bought one using the tips in this thread:  https://shmups.system11.org/viewtopic.php?f=6&t=63226). I'm hoping to get a Emotia performance in a smaller and newer device.

About the OSCC I can't say too much because I never used one, but How you plan to send the signal to a BVM? HDMI to SDI or HDMI to VGA (using these cheap converters)?



frankmonk

you can go this route:
xvi>ossc vga in> hdfury or any other cheap DAC>sync combiner>sony bvm
just too much cabling imo.
I also tried the 203rxi route but kept having weird ouput in 31khz mode.
never tried with my emotia but the fact that it only accepts 31khz input just doesn`t sound right to me. not sure how many games are booting in 15khz mode only.

LowDefAl

October 28, 2018, 11:28:35 am #3 Last Edit: October 28, 2018, 11:30:19 am by LowDefAl
Quote from: hyrulebr on October 27, 2018, 09:50:01 am
Well, you can use the X68000 with just a "sync combiner" (e.g. any extron RGB interface) at 15khz directly without the need of a OSCC or XPC-4.

You can literally tie the syncs together with a solder bridge and it will work fine on a "standard" 15khz BVM model*. No device should be needed in any form. Not ideal practice perhaps but it certainly works. Don't complicate the setup unless it's really necessary. I haven't tried that at 31khz, but if you are using a X68000 scart cable and a scart to BNC adapter for a 31khz compatible BVM, it shouldn't make a difference. 

*Not suggested for consumer displays due to signal voltages

leonk

X68k needs to be treated like a real PC.

It uses RGBHV with RGB being 0.7Vpp but HV sync is TTL 5Vpp!!  Just because you can make a scart cable for it doesn’t make it ideal. Use the VGA port as VGA and try to handle that. Most common modern usage is OSSC to LCD PC monitor.

DMR

The video board of the x68000 XVI at least, that can be removed, is this board responsible for converting the video signals?

Would it be possible to come up with a device that replaces this board that outputs HDMI instead?


hyrulebr

Quote from: LowDefAl on October 28, 2018, 11:28:35 am
Quote from: hyrulebr on October 27, 2018, 09:50:01 am
Well, you can use the X68000 with just a "sync combiner" (e.g. any extron RGB interface) at 15khz directly without the need of a OSCC or XPC-4.

You can literally tie the syncs together with a solder bridge and it will work fine on a "standard" 15khz BVM model*. No device should be needed in any form. Not ideal practice perhaps but it certainly works. Don't complicate the setup unless it's really necessary. I haven't tried that at 31khz, but if you are using a X68000 scart cable and a scart to BNC adapter for a 31khz compatible BVM, it shouldn't make a difference. 

*Not suggested for consumer displays due to signal voltages


I read somewhere that just mixing H + V isn't a good idea. But I don't know why.  :-X

Well, at 31khz the timing and frequency of X68000 signal isn't under BVM/PVM tolerance/work range. As I told, BVM D series have the dark picture and using with a BVM A series the monitor recognize the singal as 1080i and with a wooble (shaking) screen. Probably at 15hkz all PVM/BVM are compatible and that's a good thing.  :)


leonk

OP.. have you gotten a chance to try the TV one corio2? 

I'm looking for a solution to connect to my 240p/480i capable PVM (doesn't support 31k).  I was wondering if there's any box out there that will accept X68000 31k/15k and always output 240p?

TD-Linux

You can modify an Extron sync combiner to work with the TTL open collector sync outputs of the x68000, which avoids the dim screen issue:

https://nfggames.com/forum2/index.php?topic=6559.0

hyrulebr

Quote from: leonk on May 31, 2019, 05:19:52 am
OP.. have you gotten a chance to try the TV one corio2? 

I'm looking for a solution to connect to my 240p/480i capable PVM (doesn't support 31k).  I was wondering if there's any box out there that will accept X68000 31k/15k and always output 240p?


Someday I will try the tv one corio2 with my X68000! So many things to do and just a small time avaliable every week.  :(

Regarding PVM/BVM I saw this auction last month in YAJ:

https://page.auctions.yahoo.co.jp/jp/auction/q287178972

And I asked the seller how he manage to get the Castlevania to working in a PVM 20L5. Castlevania only works with 31khz and I tested in the past a 14L5 with my X68000 and got the same greenish screen, dark screen as BVM D20.

He kindly replied to me this circuit he uses to combine sync:

Monitor: SONY PVM-D20L5J ・ Cable: self made HSync + VSync â†' CSync (5V + 74AC86 + 170Ω)
https://blog-imgs-127.fc2.com/s/u/z/suzume9/74ac86.png

Taking a better looking now in the YAJ listing, picture with start screen seems a little green in the japanese text, but maybe it´just the camera/angle/reflection because the next picture (cave stage) have the colors ok to me.

I don´t have the knowledge to build this circuit to test but I plan to ask someone to do it for me in the future. If someone wants to give a try first, please let me know the results.  ;)