Title: RGB2HDMI for NeXTStation?
Post by: tt on October 23, 2024, 11:40:27 PM
Post by: tt on October 23, 2024, 11:40:27 PM
Has anyone tried using an RGB2HDMI to adapt the NeXTStation Color or Mono to work on HDMI monitors? I can't tell if the adapter would work for the resolution(s) of those machines, but it seems fairly flexible in terms of what types of systems it can adapt depending on the configuration.
Title: Re: RGB2HDMI for NeXTStation?
Post by: gtnicol on October 24, 2024, 06:31:18 AM
Post by: gtnicol on October 24, 2024, 06:31:18 AM
I haven't tried this, but one thing I was thinking about the other day is the projector boards that NeXT used. It'd be interesting to see if we can reverse engineer the schematics for those as the basis for this kind of thing. Also, given that we have the protocol specs for the monitor cable, it might be possible to use a raspberry PI or some such to directly support USB/HDMI
Title: Re: RGB2HDMI for NeXTStation?
Post by: tt on October 24, 2024, 08:02:07 PM
Post by: tt on October 24, 2024, 08:02:07 PM
Do you have a link to the projector board? Is there a digital component to the video signal? I thought it was just analog and the sound and peripherals were digital.
Title: Re: RGB2HDMI for NeXTStation?
Post by: gtnicol on October 26, 2024, 10:13:31 AM
Post by: gtnicol on October 26, 2024, 10:13:31 AM
I'll see if I can find some photos, but NeXT had a board they used for connecting to projectors and I had a couple of them.
Title: Re: RGB2HDMI for NeXTStation?
Post by: dotsam on November 16, 2024, 04:47:38 PM
Post by: dotsam on November 16, 2024, 04:47:38 PM
The RGB2HDMI is primarily designed for TTL-level digital video signals, and although it has some analog RGB support, it can't handle (https://github.com/hoglet67/RGBtoHDMI/issues/394) the refresh rate or pixel clock of VGA systems or the NeXT.
I just posted about (https://www.nextcomputers.org/forums/index.php?topic=5789) the video timings I needed to work out to use a NeXTStation Color with a video switcher/scaler.
If you search the forums, other people have had success with the OSSC (Open Source Scan Converted), or with a regular VGA-HDMI adapter. But those are a huge gamble, as it's almost impossible to know if the one you get will support sync-on-green. No-name stuff from China is likely to swap to a different chipset every 20 minutes, and even established brands will change, so you can't really trust one that worked for someone else in the past.
So either roll the dice, or get a "sync separator" that pulls Hsync and Vsync out separately.
I just posted about (https://www.nextcomputers.org/forums/index.php?topic=5789) the video timings I needed to work out to use a NeXTStation Color with a video switcher/scaler.
If you search the forums, other people have had success with the OSSC (Open Source Scan Converted), or with a regular VGA-HDMI adapter. But those are a huge gamble, as it's almost impossible to know if the one you get will support sync-on-green. No-name stuff from China is likely to swap to a different chipset every 20 minutes, and even established brands will change, so you can't really trust one that worked for someone else in the past.
So either roll the dice, or get a "sync separator" that pulls Hsync and Vsync out separately.
Title: Re: RGB2HDMI for NeXTStation?
Post by: gtnicol on November 30, 2024, 03:06:07 PM
Post by: gtnicol on November 30, 2024, 03:06:07 PM
I remembered I had the imagines on flikr for the NeXT projector board:
(https://flic.kr/p/rAtGSu)Untitled (https://flic.kr/p/rAtGSu) by gtnicol (https://www.flickr.com/photos/15578792@N02/), on Flickr
(https://flic.kr/p/rAtGSu)Untitled (https://flic.kr/p/rAtGSu) by gtnicol (https://www.flickr.com/photos/15578792@N02/), on Flickr