Connect a NeXTdimension Cube to a Flat Panel Monitor

Started by Nitro, January 28, 2006, 11:37:52 AM

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Nitro

I posted this in the old OPENSTEP forums a while ago when I was searching for an adapter to connect a NeXTdimension Cube to a flat panel monitor.  Many people around the Internet and others in the forums had found VGA adapters that worked with black hardware, but I wanted to find something that was inexpensive and available locally.  Most of the adapters I had seen were $35.00 USD or more, so I did a little searching and found these adapters.  At the time they were selling for $8.00 USD, but they're now available for $6.99 USD from http://www.a1netusa.com/product.asp?ID=w3 . I've tried these on both a NeXTdimension board (#SW3VF) and a NeXTstation turbo color (#SW3VM + VGA gender changer) and they work well.  However, they don't work with all monitors.  Minimum requirements are support for sync on green (SOG), minimum display resolution of 1120 x 832 or higher, and scan rates of 68Hz or 72Hz depending on your black hardware.  Here's a few shots of the adapters and a working system.  The monitor is an older 19" Viewsonic VX900.





Another option available is to use a monitor that works out of the box with black hardware, such as some SGI monitors.  It's also possible to use NeXT monitors with a PC or Mac.  These guys can help with that.  http://www.si87.com/MonitorSolutions/next/ .
Nitro

Slab

I'm gonna have to give one of those adapters a try.   :)
Slab

cmstar

Nitro, thank you so much.  I was just looking for this kind of information.

I have a 21" NeXT monitor, but I'm really cramped for space.  Looking to sell the NeXT monitor and put my color slab on a flat panel.  This is just what I need.

Also, for those looking into this.  DON'T hate me, I only state this for those that might find it useful.  Freepay is giving away free flatpanel lcd monitors.  It's an incentive program.  However they offer a Samsung Syncmaster 19" 940b monitor which does sync on green and the other required options for NeXT (according to the spec sheet).  You can sign up for a free one here:

http://flatscreens.freepay.com/?r=8675309

Also, does anyone know of any adapter/converter or specs/plans for one to use with a MONO slab?

I have 10 of the MONOs...with no keyboards mice or monitors...they're just collecting dust.  I suppose I should sell those too.

Nitro

Quote from: "cmstar"Also, does anyone know of any adapter/converter or specs/plans for one to use with a MONO slab?

I have 10 of the MONOs...with no keyboards mice or monitors...they're just collecting dust.  I suppose I should sell those too.

I don't know very much about video input/output in general, so maybe someone who is more knowledgeable can chime in here.  I believe a signal converter would be necessary to connect a mono slab or non-Dimension Cube to a VGA monitor.  Also, the video signal would have to be tapped off of a pass-through connector since the mono video port is shared with the keyboard input.  I'd sure like to find a working solution though, as I imagine even grayscale would look slick on a flat panel.
Nitro

cmstar

I spent about an hour last night looking for pinouts on NeXT and VGA.

Here is the interesting part.  The mono's have seperat horizontal and vertical sync (not sync on green like the colors).  This looks very much like VGA.

The main difference is that there is only 1 data line, instead of 3 (one for each color, RGB).

I also found the necessary means to power up the machine from the monitor connector.

If (and this is a big if) I get motivated, and can scrap up the right connectors from my box-o-junk.  I may work on building an adapter.

I'm wondering if I wired the single data line from the mono to all three data lines on the vga side if it would produce 'technicolor' *lol*

gborgns

I tried the mono cube driving an VGA LCD already.  It works, but there was some ghosting.  I originally did the mod to allow me to use the 040 cube cpu board test floppy, which doesn't work with the dimension board/monitor combination, to test a couple of 040 boards I acquired.

I used a spare Non-ADB sound box to perform the mod.  

I punched a hole in the back of the box for the DB-15 VGA connector and used a mating connector I found from an old cassette deck for the PCB white connector.

If you open the sound box, you will find a white connector on the PCB that has the required video signals coming from the 19 pin interconnect cable.

I directly connected the HS, VS, and ground lines to thier respective 15 pin VGA connections.  For the video, I connected the single video signal to the three VGA RGB inputs through 75 ohm resistors, one for each line.

The ghosting does not occur if only one of the R, G, or B inputs is connected.  But of course the display will be in that color and not Black and White.  The ghosting could be just a matching/drive issue, but I didn't look into it any further, since it works fine as a test box.
Turbo Color Slab, Tadpole P1000G and SS5

Nitro

Thanks gborgns, that a great solution.  I'll hunt down some DB-19 solder connectors and see if I can make it work.
Nitro

gborgns

Nitro,  
DB-19 connectors are made of un-obtainuim.  At least that is what I concluded.  I search high and low.  Plenty of DB-15's and DB-25's but no DB-19's.

It came down to either modify a sound box, make a connector (from a DB-25), find a broken mono monitor to canabilize, or butcher a NeXT monitor cable.

The sound box mod was the easiest.
Turbo Color Slab, Tadpole P1000G and SS5

urbanape

From your pictures, it appears that this adapter is used beyond the sound box, is that correct? Meaning, using an LCD screen doesn't preclude the use of the sound box? Can you upload a few pics of the cables all hooked up?

blackcube

Quote from: "gborgns"Nitro,  
DB-19 connectors are made of un-obtainuim.  At least that is what I concluded.  I search high and low.  Plenty of DB-15's and DB-25's but no DB-19's.

It came down to either modify a sound box, make a connector (from a DB-25), find a broken mono monitor to canabilize, or butcher a NeXT monitor cable.

The sound box mod was the easiest.

http://www.sfcable.com/store/24-221.html

They have DB-19's@$0.50 each.  I'm going over to a local surplus electronics store in the morning.  I'll check their stock as well.  They used to stock DB-19's as well as DB-23's for the Amiga (made of gold plated un-obtainium!)
www.blackcube.org - The Texas State Home for Orphaned and Wayward Computers

blackcube

Quote from: "gborgns"Nitro,  
DB-19 connectors are made of un-obtainuim.  At least that is what I concluded.  I search high and low.  Plenty of DB-15's and DB-25's but no DB-19's.

It came down to either modify a sound box, make a connector (from a DB-25), find a broken mono monitor to canabilize, or butcher a NeXT monitor cable.

The sound box mod was the easiest.

http://www.sfcable.com/store/24-221.html

http://www.connectworld.net/cgi-bin/ccc/05MPartDB19.html

http://www.cablesandconnectors.com/PIX/pan103.jpg


They all have DB19's in stock.  I'm going over to a local surplus electronics store in the morning.  I'll check their stock as well.  They used to stock DB-19's as well as DB-23's for the Amiga (made of gold plated un-obtainium!)
www.blackcube.org - The Texas State Home for Orphaned and Wayward Computers

Nitro

Quote from: "urbanape"From your pictures, it appears that this adapter is used beyond the sound box, is that correct? Meaning, using an LCD screen doesn't preclude the use of the sound box? Can you upload a few pics of the cables all hooked up?

Hi urbanape,

  The NeXTdimension VGA adapter plugs directly into the 13W3-style connector on the NeXTdimension color board.  There are two ways to wire the keyboard to a Cube equipped with color.  The keyboard either plugs into the sound box (as shown), or it plugs into the grayscale monitor and you can use two monitors (one grayscale and one color).  I'll try to take some pictures of the installed adapter and wiring this weekend.

Blackcube:

Thanks for the links.
Nitro

gborgns

Blackcube,

Wow!  Thanks for the sources.  None of my local suppliers had a DB-19.  They all looked at me funny when I asked.

Sure beats butchering a cable.

Let me know if you run into or solve the ghosting problem.
Turbo Color Slab, Tadpole P1000G and SS5

urbanape

so, in the case of my color nextstation turbo, I've got a Y-cable coming out of the back of the slab, with one end going to my 21" display, and the other going to the soundbox.

Looking at the first picture, I'm just not seeing where the adapter comes into play:

 

Edit by Admin: Linked to local image

Nitro

Here's a picture of the cable connections for a turbo colorstation.  The NeXTstation Color VGA adapter can be seen in the lower right between the NeXT Y-cable and the blue VGA monitor connector.

Nitro