Connecting a Turbo Color to HDMI/digital LCD

Started by rjbrown99, November 29, 2015, 11:27:47 pm

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rjbrown99

I thought I would share a success story. My goal was to connect my NeXT Turbo Color to a standard LCD with HDMI digital input. In my case, I'm using a Dell U2415 panel that has no VGA connections.

I needed a few things to make it happen.

1) 13W3 to VGA connector. These are fairly common and as long as you find one that works for Sun equipment it should work for your NeXT.

2) VGA gender changer. Female on both ends.

3) Sync separator. This converts sync-on-green to separate sync so your monitor does not have to support SOG. (Yes, there are ways to build your own for less money - I had no ability to do it so I bought one.)
http://bit.ly/1PV4tjf

4) Standard VGA cable, from the sync separator to the converter box.

5) VGA->HDMI converter box:
http://amzn.to/1LHhFR3

Note that I tried 4 other boxes and none were able to deal with the NeXT's 1120x832 screen. The one listed above works. It has a small black border at the bottom but the other 3 sides are flush with the edge of the monitor - looks surprisingly good to me.

Not inexpensive but if you really need to go digital-only there aren't a lot of options.

barcher174

Thanks for posting this! I've been curious about a VGA to HDMI solution.

rcberwick

I didn't have the same success.  I got all the same parts as pointed to on this list, incl. the same Dell U2415, but - nothing. The monitor reports no signal thru a known good HDMI cable.  Any tips re the use of the SOG box or the HDMI converter?  I am either doing something wrong (neither side of the SOG box seems to do the trick), or else not using the HDMI box pushbutton settings properly, etc.  Both boxes are supplied w/ power.  Any tips? Thanks.

Quote from: "rjbrown99"I thought I would share a success story. My goal was to connect my NeXT Turbo Color to a standard LCD with HDMI digital input. In my case, I'm using a Dell U2415 panel that has no VGA connections.

I needed a few things to make it happen.

1) 13W3 to VGA connector. These are fairly common and as long as you find one that works for Sun equipment it should work for your NeXT.

2) VGA gender changer. Female on both ends.

3) Sync separator. This converts sync-on-green to separate sync so your monitor does not have to support SOG. (Yes, there are ways to build your own for less money - I had no ability to do it so I bought one.)
http://bit.ly/1PV4tjf

4) Standard VGA cable, from the sync separator to the converter box.

5) VGA->HDMI converter box:
http://amzn.to/1LHhFR3

rjbrown99

Initially mine wasn't working either and then I read that the SOG device only works in one direction. Make sure you have it connected in the right order. Here's how mine is set up:

13W3->VGA
VGA gender changer
SOG device
VGA cable
HDMI converter device
HDMI cable
Monitor

Here's what it looks like:

rcberwick

Success! This indeed works! The problem was a bad HDMI cable.  I had tried both orders for the SOG box, then switching out to a new cable worked - and the display is really quite excellent, just as rjbrown99 says. Good rez., a small black border at the bottom.  Closest thing to the old Megapixel color monitor I have yet seen, and it beats the smaller Dell LCDs.  A tip of the hat to rjbrown99, thank you for all, and the care in even sending a photo of the setup.

Quote from: "rjbrown99"Initially mine wasn't working either and then I read that the SOG device only works in one direction. Make sure you have it connected in the right order. Here's how mine is set up:

13W3->VGA
VGA gender changer
SOG device
VGA cable
HDMI converter device
HDMI cable
Monitor

rjbrown99

Glad you also got it to work. Even in widescreen I thought the output was pretty solid.

Now I'm going to work on an ADB->PS2->USB solution so I can use a modern keyboard with it :)

cbrunschen

I wonder whether it might be worth trying to design an all-in-one converter using something like this article from Analog Devices - an AD9984A analog-to-digital video converter with sync-on-green handling, plus a ADV7513 HDMI transmitter.

The serial protocol for mouse & keyboard is known; if the remaining packets were, as well, then it might be possible to put together a "sound & video box" that offered USB mouse & keyboard support as well as analog sound and HDMI video - allowing complete replacement of peripherals for black NeXT hardware.

rcberwick

If you want to go this route, it seems that it's now hard to get the converter box from any US source.
However one can easily get them from China, e.g., Tomtop.com (also available via their store on eBay):

SKU: V1619US, Name: VGA To HDMI 4K 1080P HDTV Video Audio Converter Box Adapter For PC DVD HDTV

The output is 720p to the DELL Lcd monitor.

The cost is around $39.00.
Their std package shipping, which is free, seemed quite fast.
I have been very pleased w/ this setup.
I've tested four other "upscaling converters" and none of them seemed to work, just as noted above.  
Only this one seems to work for me.

The sync-on-green box can still be ordered from:
Web Sales
255 Comfort Lane
Bozeman, MT 59718
United States
sales@si87.com

rey

Hi rjbrown99 and rcberwick, congrats on getting this to work!

Can either of you or anybody on this thread post pictures of this?  I'm curious as to how this looks on current standard 16:9 screens.

rjbrown99 has discovered the best NeXT screen solution available on the internet...

To see NeXT on digital instead of analog.. amazing!

rcberwick

rjbrown99 is a hero for figuring all this out. I just followed his recipe.
The screen rez is not *quite* as sharp as the old Sony megapixel, but it's close.
Here is an image from yesterday that gives some idea of what 16 x 9 looks like.  It's an iPhone shot, not very good quality, but should work, I think - pls tell me if it does not.  There are the obvious moiré banding artifacts in the photo.  Still, pretty good.  With the scsi2sd in place, one can get lots of 2 gb partitions as well -- I have a "modern" 20gb machine.
If only I had the time to re-do all the remaining gnu sw, get a modern browser going - we would have a respectable machine.  IMHO still one of the most solid machine/SW combos I've ever used, and I've seen a lot of them.

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rey

Thank you rcberwick! The borders look ok.

But I take it that clarity is improved with digital over analog?

I'll try just analog first with the common Sun adapter and if it's unbearable, I'll go with this recipe!

t-rexky

Quote from: "rey"Thank you rcberwick! The borders look ok.

But I take it that clarity is improved with digital over analog?

I'll try just analog first with the common Sun adapter and if it's unbearable, I'll go with this recipe!


Please do not get confused.  You will get the best image quality if you take the NeXT video output and drive a modern "multisync" LCD with it using a SUN adapter.  This gives you the minimum number of signal conversions and therefore minimizes the losses.

The NeXT does not output a digital signal, it only outputs an analogue signal.  You therefore need to convert that analogue signal into digital at some point.  The conversion described in this thread results in an HDMI signal.  This is useful if you want to transmit the NeXT output (after conversion to HDMI) over long distances, or if the only input available to you is HDMI.

The image quality on the 19" NEC MultiSync LCD monitors, once adjusted properly to deal with the unusual NeXT frequencies, is simply SUPERB.  This has been described in other threads here, and I posted specific instructions on how to set these monitors to get the pixel-for-pixel perfect image...

cbrunschen

It might be the this Open Source Scan Converter might be useful. With standard firmware it doesn't quite handle NeXT's 1120x832 @ 68Hz input, since it's based on an FPGA it should be possible to write a bespoke NeXT-supporting firmware.

// Christian

cbrunschen

Quote from: "cbrunschen"It might be the this Open Source Scan Converter might be useful. With standard firmware it doesn't quite handle NeXT's 1120x832 @ 68Hz input, since it's based on an FPGA it should be possible to write a bespoke NeXT-supporting firmware.


It might actually already be supported: Per this answer to my question on the OSSC support forum,

QuoteThe OSSC supports digitization up to 1920×1080 so that resolution should be no problem. You just need need a monitor that supports that resolution and framerate but there are monitors for sale that support even 240Hz so it shouldn't be much of a problem.


// Christian

chrisrot

I just purchased one form my Amigas. I'll give it a try on my NeXT once I soldered it.