OSSC (DIY video digitizer & scandoubler)

[orange808]

This one works to get RGB into the SCART AV1 OSSC input from an HD15 cable. The adapter is meant for a projector, but it maps the RGB lines to their standard pins. It fits snugly into the OSSC, too.

https://www.ebay.com/itm/Optoma-Scart-t ... 1967512983

There's no telling how Optoma wired the vsync line to the SCART plug, so I just removed the sync pins from the HD15 wire. Should be a cheaper and easier alternative to building a custom cable or paying for one. "VGA" cables can be had for next to nothing at a local thrift store.

Of course, if this is a bad idea for some reason I don't know about, let me know.

[Galdelico]

My TV has a button for toggling aspect ratios on the remote control; I thought that was a pretty standard feature on consumer televisions.

Can't really tell from that photo, but nullifer said he's got a monitor, and that simple toggle is usually well buried into the OSD.

[nullifer]

Yeah unfortunately I have to go into the OSD everytime I want to change something.

[nmalinoski]

My TV has a button for toggling aspect ratios on the remote control; I thought that was a pretty standard feature on consumer televisions.

Can't really tell from that photo, but nullifer said he's got a monitor, and that simple toggle is usually well buried into the OSD.

Oh, yes, you're right; monitors rarely come with remote controls.

[Hao]

Has anyone used the OSSC with the VX3211-4K?

I know the 1080p VX3211 is highly recommended but its not easy to get hold of.

The 4k version is available to me and was hoping someone could give their thoughts on it?

Thanks

[Xyga]

Never assume they're the same monitor with a higher resolution panel just because they're sharing the same series name!

The VX3211-4K-mhd is different from the Full-HD (mh) and WQHD (2k-mhd) versions, for instance it doesn't feature the broad refreshes support, it's a standard locked-type EDID.

A lot of the interest in the Full-HD one came from its 1080p x5 compatibility along with always-available overscan, decent scaling and smoothing, and that you can get something like GroovyMAME with CRT-Emudriver fully working on it.

It's got a younger thinner-bezel brother that's called VX3276-mhd in N-A (mhd-2 in some areas, yeah the naming's confusing) mostly the same as the VX3211-mh, except with more manual aspect ratio controls, an added DP input, and a panel much more prone to backlight bleeding, because of the thin bezel. So be very careful if you buy one, you may have to return several units before getting one that doesn't show too much bleeding.

Note they're all IPS and therefore sensitive to interlaced flicker that will leave marks, so if your idea was to get one for playing something like PS2 games in bob mode from the OSSC, that' a bad one.

The 2K version VX3211-2k-mhd has the thick sturdy bezel but naturally can't offer the same pixel-perfect x5, and has a grainier panel coating, but it should have the same broad refreshes support and overall features.
Its younger version VX3276-2k-mhd should feature similar changes to the Full-Hd one.

They have a new 4K called VX3276-4K-mhd with a VA panel, but I couldn't find any full user manual showing detailed specs, only a short datasheet, so I can't tell you what it's worth.

[Hao]

Thanks for the detailed comparison!

So you don't think the 4k version is worth bothering with? Like I said, I know the 1080p version is recommended but it's hard for me to get one.

[Xyga]

Where do you live ? like I said if the VX3211-mh is not available, you can check if they have the VX3276-mhd.

And I think I've been clear about the 4K options.

[H6rdc0re]

I want to use my Windows 98SE retro gaming PC on my OSSC. Can the OSSC passthrough a 1600x1200p signal through the D-sub connector? For DOS games I'll be using 240p, for 3DFX games 480p and for other games 1200p.

[maxtherabbit]

I want to use my Windows 98SE retro gaming PC on my OSSC. Can the OSSC passthrough a 1600x1200p signal through the D-sub connector? For DOS games I'll be using 240p, for 3DFX games 480p and for other games 1200p.

yes but you can't go over 60Hz on 1600x1200

[Fudoh]

How do you plan on running DOS games in 240p ? The majority of low-res DOS games run in a 400p70 mode. If you upscale that while keeping the 70Hz refresh rate, you'll have problems on most TVs displaying that. An Extron RGB-HDMI 300 or an DSC 301 will help you to convert that to - e.g. 1200p60 or 1080p60.

[H6rdc0re]

How do you plan on running DOS games in 240p ? The majority of low-res DOS games run in a 400p70 mode. If you upscale that while keeping the 70Hz refresh rate, you'll have problems on most TVs displaying that. An Extron RGB-HDMI 300 or an DSC 301 will help you to convert that to - e.g. 1200p60 or 1080p60.

Oh I thought DOS games would run @320x200, 320x240 and 640x480. I wasn't aware of 720x400 @70Hz. I'll look into that, thanks. Perhaps my LG OLED will support it.

[maxtherabbit]

How do you plan on running DOS games in 240p ? The majority of low-res DOS games run in a 400p70 mode. If you upscale that while keeping the 70Hz refresh rate, you'll have problems on most TVs displaying that. An Extron RGB-HDMI 300 or an DSC 301 will help you to convert that to - e.g. 1200p60 or 1080p60.

My display has no issue with 400p70 on line x2 through the OSSC, it looks quite stunning too

You're right the 70Hz is problematic for a lot of TVs though

(to be exact most DOS games actually run internally in a 320x200 mode for 15kHz CGA/EGA displays, but VGA cards line double them when they scan them out)

[Kez]

Where do you live ? like I said if the VX3211-mh is not available, you can check if they have the VX3276-mhd.

And I think I've been clear about the 4K options.

Has anyone tried the 27 inch Viewsonics? The VX2757-mhd or VX2776-smhd? I am looking for a 27 inch second monitor and OSSC support would be nice, as my main display is DisplayPort only.

[Xyga]

I don't think so, anyway same warning as usual, because it's a same name brand or same series doesn't mean they work the same as X or Y known tested monitor.

Neither of the two you mention seems okay, the first one is a TN, the second an IPS without overdrive, and both don't detail the menu settings in the user guides (the bibles of ViewSonic monitors), which makes me wonder if they have the same firmware as the VX3211 featuring the convenient overscan and pixel-perfect x5.

In your place I'd rather look at the VA2756-mhd or VG2748 & VG2755 (latter two rotate both ways?) which all seem to tick all the boxes;

- presence of at least one sub-60Hz mode in the 'supported resolutions' (56Hz) which hints at the same support for custom refreshes like mine
- overscan
- overdrive

Only difference I notice is the aspect ratio controls, both are different from the VX3211, the VA2756 gives a lot of options, the VG2748/55 only full and 4:3, though I don't think that'll be a problem.

The VA2710-mh seems to tick the boxes too, but it features only one HDMI and VGA.


Now the only problem when you're looking for a 'swiss army knife' monitor for the OSSC there, is that most of those that seem to be okay for the job are IPS, and that type of panel doesn't like the OSSC's bob-deinterlaing mode. SO if your plan is to play tons of PS2 games for instance, then give up on those two.
ViewSonic have a single 27" VA (no issues with bob-deinterlacing) which is the VG2739, but that's another one of those not giving enough details in the user manual so like the two you mentioned it's a black box.

EDIT: for the masochists who'd still rather have a 27" TN (the only alternative besides VA for handling the OSSC's bob-deinterlace mode) then the VX2758-P-mhd by the users guide also ticks the boxes. It is a 144Hz FreeSync though.

Anyway when browsing for ViewSonic monitors, download the user guides at the bottom of each product's page, that's where all the real useful info is, nowhere else.



TL;DR list of 27" ViewSonic that should be okay for the OSSC (info gathered from manuals, not tests)

VA2756-mhd
VG2748
VG2755
VA2710-mh
VX2758-P-mhd

[ldeveraux]

I don't think so, anyway same warning as usual, because it's a same name brand or same series doesn't mean they work the same as X or Y known tested monitor.

Neither of the two you mention seems okay, the first one is a TN, the second an IPS without overdrive, and both don't detail the menu settings in the user guides (the bibles of ViewSonic monitors), which makes me wonder if they have the same firmware as the VX3211 featuring the convenient overscan and pixel-perfect x5.

In your place I'd rather look at the VA2756-mhd or VG2748 & VG2755 (latter two rotate both ways?) which all seem to tick all the boxes;

- presence of at least one sub-60Hz mode in the 'supported resolutions' (56Hz) which hints at the same support for custom refreshes like mine
- overscan
- overdrive

Only difference I notice is the aspect ratio controls, both are different from the VX3211, the VA2756 gives a lot of options, the VG2748/55 only full and 4:3, though I don't think that'll be a problem.

The VA2710-mh seems to tick the boxes too, but it features only one HDMI and VGA.


Now the only problem when you're looking for a 'swiss army knife' monitor for the OSSC there, is that most of those that seem to be okay for the job are IPS, and that type of panel doesn't like the OSSC's bob-deinterlaing mode. SO if your plan is to play tons of PS2 games for instance, then give up on those two.
ViewSonic have a single 27" VA (no issues with bob-deinterlacing) which is the VG2739, but that's another one of those not giving enough details in the user manual so like the two you mentioned it's a black box.

EDIT: for the masochists who'd still rather have a 27" TN (the only alternative besides VA for handling the OSSC's bob-deinterlace mode) then the VX2758-P-mhd by the users guide also ticks the boxes. It is a 144Hz FreeSync though.

Anyway when browsing for ViewSonic monitors, download the user guides at the bottom of each product's page, that's where all the real useful info is, nowhere else.



TL;DR list of 27" ViewSonic that should be okay for the OSSC (info gathered from manuals, not tests)

VA2756-mhd
VG2748
VG2755
VA2710-mh
VX2758-P-mhd

Since you refuse to quote, what exactly are you talking about??

[Xyga]

Of fairies and balloons, obviously. Just felt like it, suddenly.

[Kez]

Of fairies and balloons, obviously. Just felt like it, suddenly.

Many thanks for the detailed response, I appreciate your input! I'll investigate the monitors you listed. I am tempted to go for the 32 inch one, but my "main" monitor is 27 inch and I feel like the size difference would be annoying.

[Xyga]

The VG ones are a bit expensive but so well-equipped I'm jealous, and yeah I've checked they rotate clock & counter.

You will note there's little variants locally,
like the VX3276-mhd a.k.a VX3276-mhd-2 (differences? none obvious...)
or VA2710-mh a.k.a VA2710-h (latter has no speakers)
maybe more

[H6rdc0re]

I’ve been really into retro PC gaming lately.

@Marqs: could you please add a line 2x mode for 800x600p resolution?

[Konsolkongen]

The top 1/4th of the image is brighter than the rest, is this normal behaviour?

GameCube in 240p, component cables, and the following settings:

Pre-ADC Gain 7

Scanlines:
Sl. strenght 50%
Sl. hybrid str 112%

Using the boot screen of Gameboy Interface I can barely see the top rows of scanlines but I can see the rest of them fine. Unfortunately it's impossible to capture on camera.

Never noticed this before on the OSSC, but the Framemeister has a very similar quirk. Anything I can do to fix it on the OSSC besides lowering Pre-ADC to 6?

[TiddlyWinks]

Anyone know of any good asus TN 27" 1ms monitors is the usa that play nice with the OSSC?

I see the VP278H in the UK, but here we have the VP278H-P. Not sure what the "-P" suffix indicates.

[Xyga]

Another ViewSonic monitor I hadn't paid attention to is the XG3220.

It's a 32" 4K VA (w/ basic FreeSync & HDR), which according to the user guide, features what usually puts ViewSonics above the rest for OSSC use.

What's daunting is that it features a significantly increased number of supported modes listed as examples, as well as a few so-called gamer-friendly features (typically useless but heh normally they shouldn't get in the way)

Most importantly: no idea how the scaling options, like the behaviour for x5 modes and the overscan feature work there, since those are crucial to the OSSC and what makes ViewSonics worth.

Anyway what's a surprise for me is that it's only...400 bucks.
Compared to their other big 4K options that's significantly cheaper.

Among all models they currently list that would be the one I would be most curious to try, don't have the funds now tho. Tch.

[TiddlyWinks]

How do you guys know if a TV has a HDMI port which bypasses the TV processing? Is it listed in the specs somewhere?

[Konsolkongen]

The top 1/4th of the image is brighter than the rest, is this normal behaviour?

GameCube in 240p, component cables, and the following settings:

Pre-ADC Gain 7

Scanlines:
Sl. strenght 50%
Sl. hybrid str 112%

Using the boot screen of Gameboy Interface I can barely see the top rows of scanlines but I can see the rest of them fine. Unfortunately it's impossible to capture on camera.

Never noticed this before on the OSSC, but the Framemeister has a very similar quirk. Anything I can do to fix it on the OSSC besides lowering Pre-ADC to 6?

Same thing with SNES RGB and the white screen in 240p test suite. I guess this is normal behaviour then

[nmalinoski]

How do you guys know if a TV has a HDMI port which bypasses the TV processing? Is it listed in the specs somewhere?

If your TV has one, it should be in the manual. If it doesn't, then you would need to use a VGA input (if your TV has one), enable game mode (If possible), or buy a commercial monitor (potentially expensive).

[TiddlyWinks]

Thanks. I guess I don't have that type of input with my tv.

I just got my OSSC today and have a question about Sync attenuation before I use it.

Watching this video https://www.retrorgb.com/csync.html cleared up some questions I had regarding sync, but I had a couple questions still.

1) Does the OSSC has a sync stripper built in?


2) Do any of the other lines need attenuation or checking before hooking them to the OSSC?


Thanks, I don’t want to damage my new OSSC.

[nmalinoski]

1) Does the OSSC has a sync stripper built in?

The OSSC will accept sync-on-composite, sync-on-luma, clean composite sync, and sync-on-green (Basically everything that's out there). You don't need cables with sync strippers to use the OSSC.

2) Do any of the other lines need attenuation or checking before hooking them to the OSSC?

RGB and YPbPr should fall into their typical consumer video 0.7Vp-p range on all inputs. Sync on AV1 should be typical consumer video 1Vp-p (-0.3V to +0.7V), and sync on AV3 should be 5Vp-p TTL.

All audio inputs assume line-level audio, so don't try to feed it amplified audio from an arcade board.

[TiddlyWinks]

1) Does the OSSC has a sync stripper built in?

The OSSC will accept sync-on-composite, sync-on-luma, clean composite sync, and sync-on-green (Basically everything that's out there). You don't need cables with sync strippers to use the OSSC.

2) Do any of the other lines need attenuation or checking before hooking them to the OSSC?

RGB and YPbPr should fall into their typical consumer video 0.7Vp-p range on all inputs. Sync on AV1 should be typical consumer video 1Vp-p (-0.3V to +0.7V), and sync on AV3 should be 5Vp-p TTL.

All audio inputs assume line-level audio, so don't try to feed it amplified audio from an arcade board.

Good stuff. Thanks! I think I'm good to go now.

[CesarDRK]

[EDITED] --> See next post.