Retro AV |OT| RGB, CRTs, Upscalers, and more

Video Games
#1509

Was looking at some emu docs and like Mednafen both Xebra and Nocash make no mention of 384 at all, only 368. This is also reflected in the width option that Xebra allows you to select from in the video options.

http://drhell.web.fc2.com/ps1/

https://problemkaputt.de/psx-spx.htm#graphicsprocessingunitgpu

The Nocash one is interesting as 368 is set apart from the other horizontal resolutions but I’m not bright enough to parse the rest of the text beneath it to work out why!

The weird thing is that emulator docs seem to always mention 368 but more general overviews like the below always mention 384 instead.

https://www.zophar.net/fileuploads/2/10731bgqkx/playstation.htm

#1510

yeah I recently moved to Xebra for testing, and noticed this as well. I’m pretty sure they’re the same thing, but I can’t explain why there’s such confusion in terms between the two. This is helpful, though, thanks.

#1511

In the nocash doc it lists the 10 resolutions possible on the PSX GPU. Framebuffer section quite near the top.

H: 256, 512, 320, 640, 368
V: 240 or 480

(368 having a horizontal frequency of 7.603200MHz)

The “bit” (1, not 0) that activates 368 mode is nothing of concern IMHO. Imagine it like a dip switch, for 368 it needs to be on (1 ) and for all other horizontal modes it needs to be off (0).

A little lower down it also mentions dot clocks, where Namco GunCon chip has a slightly higher frequency of exactly 8.0MHz and scans 385 horizontal pixels.

This implies that an emulator whose GPU code isn’t absolutely accurate could produce different horizontal scan line widths. To get 384 horizontal width, the frequency would be 7.933774MHz.

I would say 384 is a mistake that has propagated.

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#1512

more and more this seems to be the case from looking around, and having the more math-y aspect explained to me. One of those long-lasting myths around retro A/V it would seem. Appreciate you guys talking it over. I’ve decided to use 368 in my spreadsheet. I think there might be games that use something a bit weird that isn’t typical 368 (Tekken 3 was giving us really odd numbers, for example), but that’s TBD.

Otherwise, while there are quite a few games that use a million resolutions (I’ve seen games which are regularly using as many as 4 resolutions, including interlaced ones), things seem to stay within the described spec for the most part.

2 Likes
#1513

The PS1 outputs horizontal padding with every single resolution. You can see this in Mednafen as by default it shows this in the 4:3 frame, which is why in the earlier link I posted people were saying it was incorrect by showing a diamond shaped bios logo and too skinny aspect ratio.

“By default, Beetle PSX includes horizontal padding (black bars or ‘pillarboxes’ on either side of the screen) to emulate the same black bars generated in analog video output by real PSX hardware. This horizontal padding can contain garbage pixels that are generated when the game’s width mode is smaller than the display area width in the emulated GPU registers.”

The crop over scan option removes this padding and makes all the resolutions display correctly at 4:3, showing you only the active area. You can see this yourself with Xebra as 368 crops and misaligns the image with Street Fighter Zero 3’s arcade resolution mode whereas Medanfen with crop overscan off displays it correctly.

So I don’t think 384 is a mistake but a resolution that can only be achieved if you go beyond what is the normal active area for that mode and draw into the padded area. Something that as far as I can tell only Capcom did for a very small number of games.

2 Likes
#1514

Good catch! The nocash document says Pandemonium 2 uses a larger width, but doesn’t specify exactly what that is. Do we know?

#1515

384 being the total and 368 being active makes sense to me, and would explain the confusion, yeah. given 368 seems to be the ‘official’ spec, I’ll keep with that.

I haven’t checked Pandemonium 2 but it was referenced as exceptional in another document I saw, too. Guess I should do that.

1 Like
#1516

If the time sleuth is too expensive for you, there’s also a nearly free if more time consuming alternative using a raspberry pi:

#1517

Hey all. Finally attempting to get around to replacing the Extron DSC 301 HD that I had that seems to have died out unfortunately. I was using the device to take the 960p signal of the OSSC and scale it to 1080p for my TV to work more easily with. I may consider just buying another but I thought I’d ask if any of you know of a device that may be able to accomplish the same thing for cheaper. I tried a little HDMI powered DVDO Micro scaler but it didn’t seem to want to attempt to scale the 960p signal at all.

1 Like
#1518

So I finally discovered that the issue I was having with my N64 was caused by my Otaku Games Switch.

It’s no longer accepting the RGB sync on luma signal, and just outputs a buzzing blue image but I borrowed a SCART to BNC break out and hooked it up directly to my 20L2 and it worked first time with no issues. The interesting thing is that all my other consoles work, I’ve mixed and matched inputs, tried a new cable, a new power supply.

I’ve started the return process with Otaku games so it will be interesting to see how this pans out. I’ll be sure to post my experiences here.

1 Like
#1519

New OSSC firmware samples the active area of PSP games

800×678

Shmups link

Doesn’t work on PC CRTs T_T

2 Likes
#1520

Neat. Between this and the Sharpscale hack for Vita/PSTV a good couple of weeks for PSP.

1 Like
#1521

So I picked up a cheap powered component video switch for my BKM-129x clone card. I’ll post some impressions once I confirm it isn’t adding any noise or causing any issues. Looks to be similar in design to the Monoprice Switch.

The other bonus is the wiring in my house was causing issues with my GC and my PVM20L2. The fact that the switch is powered seems to bring the signal back in line so the monitor accepts it no problem.

image
image3024×4032 2.39 MB

3 Likes
#1522

Tidy!

#1523

Can anyone recommend a good quality component video switch. The one I just bought despite working fine the first day now refuses to stay on any input other than 2 (despite being a manual switch)

I’ve read good things about the Monoprice Switch but I don’t think it’s available at the moment and I’m located in Australia.

#1524

The monoprice switch is garbage, don’t bother. Any flashes to white screens will cause a signal drop if you feed to a digital display / ossc or ugly darkening if you’re feeding to a crt. I have two of them and had to replace them because they’re no good.

I tried ordering the otaku one but 2 months after I paid and 2 months of excuses they stopped responding to any inquiry on when they would ship and I had to get paypal to refund me.

I ended up buying a few Philips Manual HD Switcher SWS2325W/17 which were sold new open box. 2 arrived new and one was visibly used which was very weird. They are combo composite/svideo/component switches with only 3 of the inputs capable of doing component so it may not suit your needs but the signal quality is good and it doesn’t drop on white screens. I’ve heard good things about their auto switchers and the pelican auto one as well but I’m pretty scared away from any powered switches at this point.

1 Like
#1525

Not that I doubt you, but I have not had any issues with mine. It may have been something in your chain which it didn’t like. It isn’t that great of a Switch though and does nothing special and is not worth waiting for.

There are also always BNC matrix switches in case you want something more industrial grade and full proof.

#1526

The JVC - JX-S777 AV Selector(Industrial Component Switcher) and Extron Crosspoint (Industrial BNC Switcher) are top notch. Sony also made Industrial BNC switchers, they are on eBay from time to time.

1 Like
#1527

I have tried several consoles on 2 different hd/4ktvs and two CRTs on two different monoprice switches, direct into TV and into an OSSC. A flash to a white screen consistently causes issues, in games or dvd movies. Try a Resident Evil title screen.

1 Like
#1528

Thanks for the tips everyone!

The frustrating thing is I’d be fine with this switch if it didn’t keep flicking back to input 2 despite being a manual switch. I’ve got the day off today so I’ll do some troubleshooting. I just had a thought that maybe mounting it sideways is causing it.