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Using a VGA -> HDMI adapter.

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First post, by sketchus

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Hi all,

I've been setting up my 98SE PC and finally got it working the way I like. Only negative is I've been using a fairly cheap monitor, that doesn't have very good colour accuracy etc. I'd like to use my main PC monitor, since it's a lot better, but it only supports HDMI. Since the monitor I can choose the aspect ratio, will a VGA to HDMI adapter just work?

Something like:

https://www.amazon.co.uk/Converter-Analogue-N … rds=vga+to+hdmi

My LCD supports up to 100hz so I'm hoping I can still correctly use the correct refresh rates and so on.

Any advise would be great.

Oh the GPU I'm using is a TI 4200 AGP 8X.

Reply 1 of 20, by Predator99

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I also own a cheap VGA-HDMI converter. But on my Sony-TV it shows no startup-screen (640*480/60?) and there is no Full-HD support on the TV with this converter.
Your choice looks better than mine.

I am now using a VGA with HDMI-out...much better.

Reply 2 of 20, by idspispopd

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Does your video card have a DVI output? DVI-D is electrically the same as HDMI (video only, no audio), so you could use a passive adapter an get an essentially native solution.
A lot of GF4 cards have DVI output, probably the majority. But I understand if you don't want to get another GF4 card just for DVI.

Reply 3 of 20, by sketchus

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It does have a DVI output and I bought an adapter but sadly it doesn't seem to work properly with my main screens. It just causes my PC to lockup before it even posts if connected. It's temperamental though. It'll work plugged into my 4k TV just fine, but my monitor causes the lockup. If I plug it in after its booted the card sees the monitor but hangs if I try to display on it.

Reply 4 of 20, by Scali

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I recently bought a cheap VGA-to-HDMI converter, and it works fine for me: http://www.ebay.com/itm/162249607710?_trksid= … K%3AMEBIDX%3AIT
(select the VGA-to-HDMI option in the choice box, if it comes up with the GBS-8200 first).
It converts signals to 1080p, and the display quality is very good. Note that some TVs only support 1080i, not 1080p. I use it on a 4k monitor though, so no problem.

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Reply 5 of 20, by Eendje

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Make sure the converter supports 720x400 70 Hz. That's the resolution for VGA text mode. My converter does not support it. I see a blank screen and can't even see the BIOS setup program.

My solution was to buy a cheap 17 inch LCD monitor. Works fine for me and it has the proper 4:3 aspect ratio. A second hand monitor may even be cheaper than a new converter.

Reply 6 of 20, by Predator99

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For sure I also mean a graphics with VGA with DVI-out...and a DVI-HDMI Adapter.

As written I have the same issue with the VGA text mode. I am not sure if its 720x400 70 Hz at power-on for all Computers, I assume it depends on the graphics card.

Reply 7 of 20, by keenmaster486

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Eendje wrote:

My solution was to buy a cheap 17 inch LCD monitor. Works fine for me and it has the proper 4:3 aspect ratio. A second hand monitor may even be cheaper than a new converter.

This. I would opt for this any day of the week rather than deal with converters.

World's foremost 486 enjoyer.

Reply 8 of 20, by sketchus

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Thanks for the advice all.

Can I just check - is it JUST the bootup screens that are 720x400 70hz? If everything else is different I can cope since I could just hook up my budget monitor if I need to change any settings. If everything else works that'd be fine.

Reply 9 of 20, by Predator99

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If you are only working with windows you will not have any trouble.

There are also some DOS Games with customized resolutions that will not run at all with such adapter...i.e. Turrican 2. This will also affect a DOS-box.

Reply 10 of 20, by kenrouholo

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If you want info on scalers that work with 720x400, and you want info on the GBS-8200, check out the site shmups.system11.org... it's kind of like this site except most of them are into consoles, not PCs. Much of the same information applies to both. And some consoles such as the Sega Dreamcast actually output 720x400, so scalers that people use on the Dreamcast should work fine for you as well. Edit: Though actually I'm not 100% sure about the 70Hz refresh rate but hey knowing the resolution is supported would be a good start.

People on that site tend to like the GBS-8200 and 8220 for the price and some people mention using it with Dreamcast, but I saw mostly offhand mentions of that. I however have never tried either one (I have other scalers but not cheapies) so can't offer any first-hand info.

Edit to add: There's a guy with nick "Fudoh" over there that has a site where he's commented on 2 or 3 dozen scalers and his experience with them. Many more than I've tried personally (I have a DVDO Edge, a Micomsoft XRGB Mini, and I used to have a DVDO VP50).

Last edited by kenrouholo on 2017-03-01, 17:58. Edited 1 time in total.

Yes, I always ramble this much.

Reply 11 of 20, by sketchus

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^Very interesting, I will check out the site shortly.

I had a bit of a stroke of luck in that I have two monitors on my desk, and that my second one actually seems to support 70hz despite being listed as 60.

That VGA adapter I listed above doesn't seem to work, at 720x400 but I picked up the more expensive Hammerhead VGA to HDMI adapter after hearing very good things about it so I'm quite hopeful for that. If it's a complete failure Amazon has a nice returns policy so that's good.

But yes I'm hoping that between the two monitors I have here I will have all bases covered within having to switch too much. If I can boot into DOS/Windows not seeing the BIOS etc wouldn't be a massive problem anyway.

Reply 12 of 20, by dr_st

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idspispopd wrote:

Does your video card have a DVI output? DVI-D is electrically the same as HDMI (video only, no audio), so you could use a passive adapter an get an essentially native solution.

Surprisingly, DVI is electrically the same as HDMI, video and audio. There are no specific pins for audio in HDMI - it's part of the same stream. It's just that most hardware implementing DVI does not bother to process the audio portion of the stream (since it's optional for DVI, but mandatory for HDMI). There were a few select AMD cards that allowed audio output via DVI. I am not sure I ever so a monitor that received audio via DVI, though.

Up to single channel, HDMI and DVI are really the same signal pins in a different shape of connector. Beyond that, things diverge, as HDMI does not implement higher resolutions via a second channel, as DVI does; instead, it raises the base frequency.

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Reply 13 of 20, by sketchus

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Just an update for anyone who stumbles across this thread looking for a similar answer.

The Hammerhead Adapter came and seemed to work very nicely at higher resolutions, and while it still worked at lower, there seemed to but a lot of noise which increased the lower the resolution. I can't honestly say if it was an issue with my setup or the adapter, but from the reviews I've read and another thread on this forum it doesn't necessarily seem to be a consistent thing. If you need VGA -> HDMI I'd still say it's worth a shot, especially if you will work at higher resolutions. No input lag (or next to none) either.

With regards to my specific case, I was getting a bit disheartened when I reconnected the DVI -> HDMI adapter and all of a sudden it works perfectly! Not sure what happened, as I'm triple checked it was plugged in correctly.

Only issue is my monitor recognises resolutions like 320x200 as a 16:10 resolution so the top edge is ever so slightly cut off, but I don't think I consider it an issue. Not one worth worrying about.

Oh and I also learned Nvidia drivers on 98 definitely require trial and error. For example, 77.72 at low resolutions would repeat the image three times, making it unusable. On 81.98, if I changed to certain resolutions it wouldn't display and I couldn't even boot into Windows (well it'd load but I couldn' see anything on screen, just hear it).

All part of the fun though.

Reply 14 of 20, by dr_st

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sketchus wrote:

Only issue is my monitor recognises resolutions like 320x200 as a 16:10 resolution so the top edge is ever so slightly cut off, but I don't think I consider it an issue. Not one worth worrying about.

320x200 is a 16:10 resolution.

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Reply 15 of 20, by elianda

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There is a bit more to it:
320x200 is a 16:10 pixel resolution
the corresponding analog mode is 640x400 (pixel doubling)
which is shown as 4:3 aspect ratio.

The important point here is that the pixels of the low res VGA modes are not quadratic, whereas modern TFTs by default assume the input pixels as quadratic. So just scaling to max. size may not help if the monitor keeps showing 16:10 while it is actually 4:3. It probably depends on the monitor if there is a aspect ratio setting.

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Reply 16 of 20, by dr_st

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Yes, there definitely is more to it than that. 😀

640x400 is also 16:10, of course. But as old CRTs were 4:3, they would display it and 320x200 with non-square pixels. Game designers knew that, so they designed the graphics to look correct with non-square pixels. Therefore, for such a game to look correct on a modern LCD, the LCD needs to force the ratio to 4:3. Some of them may do it automatically for certain resolutions, others have a forced aspect setting.

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Reply 17 of 20, by Michadeon

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I have been using a VGA-HDMI adapter for my Raspberry Pi, since my spare monitors are restricted to VGA, which works flawlessly (video + separate sound signal), and with the intention of sending you a link, I noticed that the adapter is "inverted" from what you are apparently looking for (relative to the cabling and monitor you are using 😀 ) ... but then it dawned on me: would there be any real disadvantage to using such an adapter on the DVI-port of the monitor, and connecting it with a proper (=filter) VGA cable to the Wi98SE machine? I know that there are length restrictions, but as long as the cable is filtered and not longer than 50feet/15 metres, with a VGA signal source, would there even be any noticeable loss whatsoever? 😕

Reason for this question are several passive VGA-HDMI adapters that I have been seeing lately, which do not need an external power source, like this one.

(Also, the adapter I originally meant to recommend is this one, but I couldn't find it on the British Amazon 😢 ... but since you have found a proper one, all is well!)

Reply 18 of 20, by dr_st

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HDMI-VGA and VGA-HDMI are different adapters (really converters). You cannot just take one and magically make it work in the other direction. It's best to keep this in mind at all times to avoid confusion.

A working passive HDMI to VGA or VGA to HDMI adapter cannot exist. Small or big, it's active.

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Reply 19 of 20, by Michadeon

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Hm, wasn't aware of that distinction. Good to know/learn then. 😊

As far as active/passive adapters go, maybe I used wrong technical wording, but I still meant an adapter without the need for an external power source (in this case an HDMI-to-VGA, as per 2nd link), which, if it indeed works as advertised, would be cool (also product link, no need for power cable, unless I am missing something 😕 ...)