hacking the DVI to ADC converter

bomolub wrote;
>I have an extra Apple 17-inch flat screen CRT

I'm confused, you say your Apple CRT display has an ADC connector plug? I thought all Apple's recent CRTs used standard VGA HD-15 plugs. Of course, this will probably be one of those things where I'm just completely out of touch!

To which port do you wish to attach this display, the DVI port or the ADC port? You mention this is to be your second display, what's the first display and to which port is it attached?

My thinking, based on what you've written initially, is that you've got a VGA plug on this second display and you want to connect it to the ADC port on your display card. In that case, you need an ADC to VGA adapter, eg; http://www.drbott.com/prod/db.lasso?code=0117-ADCV

$25 sounds like a fair price.

Dan K

dankephoto wrote:

I'm confused, you say your Apple CRT display has an ADC connector plug? I thought all Apple's recent CRTs used standard VGA HD-15 plugs. Of course, this will probably be one of those things where I'm just completely out of touch!

He has the last CRT display Apple made, the one with the transparent casing. Those models had ADC.

I'm thinking that honestly, your best bet would be to switch the monitors--use the CRT on your video card's ADC port, and use the adapter on your Studio Display. You should be able to rearrange them in software to keep the primary display on the Studio Display, if that's what you want.

I don't think hacking that adapter would work out well. And to answer your question, the casing is likely glued together.

I'd almost argue that the best strategy might be to chop the end off the monitor's cable and wire the appropriate pins directly to a DVI connector. (You might also want to wire up the USB pins to a stub chopped off a USB cable while you're at it.) That way you can return the Apple DVI/ADC connector to the store unharmed and bite the heads off the "Geniuses" that sold it to you.

The video quality is likely to be slightly superior, as you'll be eliminating a connector interface in the middle of the line.

I guess the question really comes down to whether you'd consider it sacrilege to cut up the monitor cable. Those monitors arn't worth a whole lot these days. (Probably not much more then the $99 Apple charges for that DVI to ADC adapter.)

--Peace

I have two of these CRT monitors -- the first one is hooked to the ADC connector on the video card. The current second monitor is a Sony CPD100-ES curved screen, which really sucks next to the Apple.

This is why I need to get this adapter working.

Glued, huh. I guess this is why they call it hacking.

I agree, the monitors aren't worth all that much in terms of money, but these are fine displays, and I have used my first one for 4 years now trouble free.

I'd still say you'd be best served cutting up the monitor cable, if there's any chance of returning the DVI/ADC adapter. About the only piece of it you'll be using is the ADC plug (and the USB cable stub) and... you might want to make *sure* it actually has contacts in the analog pin locations. (It might not. As noted, the DVI connector didn't.) If it doesn't, then it's officially completely useless.

--Peace

I almost agree with you, but...the adapter supplies the +25VDC@4 amps that runs the monitor.

The whole deal about ADC when they introduced it was that a power cable to the monitor was eliminated. The power for my first display comes out of the computer's internal supply through the video card. The DVI port has only +5VDC available.

So I could return the Apple adapter to the "Geniuses" (quotes are definitely in order here) but I would still have to come up with a compatible power supply.

Once more, I agree, these monitors aren't worth a lot monetarily, but the display is excellent and I still feel determined to make this work.

Hmm, though, you've got me thinking. Any ideas on where to get a supply that could put out a clean +25VDC@4 amps? (The specs on developer.apple.com say 25 volts. In the back of my computer's manual it says "DC monitor output: 4.0 amps max at 28 VDC).

Guess I'll look on Mouser to start. The idea of being able to return the adapter is an attractive one. Bad or lazy engineering IMO -- they should have supplied the analog signals.

Ah, I'd forgotten about that.

Of course, it's worth checking to see if the power supply that comes with the adapter is powerful enough to run the monitor anyway. I imagine the LCDs it does support draw a *lot* less then 4 amps.

See if there are any good electronic surplus houses in your area. Places like HSC ( http://www.halted.com ) usually have a whole wall of assorted open-frame regulated power supplies.

Anyway. I have to admit I just find the whole idea of a $99 cable adapter just... eeeegh. :^b

--Peace

Yikes, what PITA! With almost any other display/card combo you'd have no problem, but frickin' Apple with their screwy ADC!

My best suggestion would be these three things:
get a DVI->VGA adapter (~$10 on eBay)
replace the display's entire cable with a chopped off VGA cord/plug (saving original)
get a 28V 1.5A PS and install an appropriate connector in the display, hopefully not too hard to find

sheesh!

Dan K

http://docs.info.apple.com/article.html?artnum=58673

Thanks, guys, for the responses. Glad you steered me away from hacking the adapter.

Dan K, I am basically going to go with your suggestion, though I think probably I will try to get a 4A or > power supply. Don't think 1.5A would be sufficient.

As one of you mentioned, the power supply in the Apple adapter might not have been adequate to power this CRT. Anyway the $99 POS will go back from whence it came.

PITA it is, but I haven't done any hardware mods since my S100 days, so maybe I'll have some fun too. Maybe I will try to write this up and submit it; providing of course that I am successful.

Now to try to find a power supply.

Your saying a CRT runs from a 25V powersupply @ 4 amps! Wow! I always thought CRT's needed a lot more juice.

One thing though, when the monitor degausese and turns on, im pritty sure its going to draw more that 4 amps...

Or have i missread the posts and your talking about a flat panel? Im confused...

On the video card next to the connector (and also in the manual for my computer) it is actually 28VDC @4A max. This is the last CRT Apple made and the only CRT ever made that plugs into the Apple Display Connector.

This is bumming me out

I just ordered a dual 2.5 G5 with the NVidia 6800, now after reading this thread I went and looked here, http://docs.info.apple.com/article.html?artnum=75286 and read this, 2. The DVI to ADC Adapter is compatible only with LCD displays. It is not compatible with the Apple Studio Display 17 (ADC), as this is a CRT display. This thing is going to look stupid with one of my CTX crt's attached to it.......

I am in the same predicament. I am trying to hook up two of these Apple CRT displays to one computer. I found a way to make it work but am still trying to perfect it. Figuered that I should share.

I bought Gefen’s DVI to ADC Extend-It converter off of eBay, and connected the second monitor’s ADC plug into one end of the adapter, and then for the DVI port on the other side, a DVI-I -> VGA adapter, and an additional VGA cable M-M plug to connect it to my second video card. Believe it or not, this actually worked, although with some caveats.

The image on the second monitor looks great, although is ghosting slightly. Not sure why yet; it could be the VGA M-M cable that I am using (I need to try a more robust SVGA cable) or the DVI-I -> VGA adapter (I need to try a DVI-A that only continues the supposed “analog� signal from the monitor.
Also of note, and more applicable to your situation, I don’t have all of the monitor control panel options on the second monitor. Whereas on the primary one that is connected right to the computer, you have controls for horizontal/vertical height and so forth, the second monitor’s only has resolution and color settings. I cannot resize the image on the second monitor whatsoever, OS X seems to be treating it as a second monitor, just not an Apple one. It assumes that this second display device has controls on the outside of it for making these changes, which you and I both know is infuriatingly untrue. I love Apple making all of this so much “easier� for the end user.

I’m going to keep trying to figure this out; I thought it was good if I shot you this e-mail as you may have equal insight into my problem, and perhaps it saves your cable from the chopping block. In the spirit of sharing information I’ve so far come to this: The Gefen converter box actually works (despite what their website says), just not perfectly.

Interesting news about the Gefen device. I hadn't even considered it based on experience with the Apple device, and what their web page said.

If you have the Apple Developer software installed, find an app called "USB Prober". You can run it and see what USB devices have been detected. The monitor(s) in question show up like this: 'Low Speed device @ 5 (0x08230000): Composite device: "Studio Display"'. A lot of detail on the connection is also available which I haven't quoted.

I think you should do this and see if both devices are detected. If not, there may be a USB connection problem with the second monitor.

It is my belief that all the software controls for height, width, etc., are done through USB i/o, whereas color and resolution are handled through the video card.

The developer software is free, you just have to register as a developer. If you don't want to go through all the installation hassle, perhaps there is a way "somebody" could squirt a copy of "USB Prober" to you. Does this forum have a way for members to email one another directly? Maybe the moderators would forward an email?

If you can run it, and do see the second monitor as a USB device, we should compare results on the "fine print" of the connection detail. Might prove illuminating.

Congrats on getting as far as you have.

BTW, I have not progressed any further in my project aside from finding and ordering a 28VDC supply.

I sent you a private message with my e-mail in it; check your inbox. I'm also hoping this scenario with the Gefen adapter isn't too crazy with regard to powering--the brick power adapter that it comes with gets VERY hot, and I hope it wasn't just designed to power LCD screens. I've only been running this setup for a couple days so it's too soon to tell whether I'll start a fire or not.

Any ideas as to why the image is ghosting on the second monitor?

With all of your wiring and adapters, I should think that there is a little lag-time. It's a little like a passive matrix LCD, the display can draw faster, but the integrated controller on the display can't draw that fast. In your case, the VGA wiring is probably too slow.

wallygeorge wrote:

I sent you a private message with my e-mail in it; check your inbox. I'm also hoping this scenario with the Gefen adapter isn't too crazy with regard to powering--the brick power adapter that it comes with gets VERY hot, and I hope it wasn't just designed to power LCD screens. I've only been running this setup for a couple days so it's too soon to tell whether I'll start a fire or not.

http://www.gefen.com/kvm/product.jsp?prod_id=1203

It says it's for "Flat Panel Displays". So you might just start a fire yet. ;^>

From what I can tell the major difference between this item and the Apple one is that this one carries the analog lines through, while the Apple one does not. Probably an oversight, honestly. I'd check the rating of the power supply. If it's less then something like 2 amps I'd be willing to bet you'll kill it sooner then later.

Any time you start stacking adapters or connectors you'll get that. I hate having to use a KVM on my desktop machines for that very reason.

--Peace

Thanks so much to everyone that helped me pull this one off!

Fixed the ghosting issue with a different cable; I plugged a DVI-A -> VGA cable into the Gefen adapter and the image on the second montor is perfect!

On Bomolub's advice, I used USB Prober and no second monitor was detected; I pinned it down to the USB cable (bad), tried another one, and the control panel worked on the second monitor as well!

The power issue is still outstanding, however. The Gefen power adapter has a maximum output of 60 Watts (!!!). The Display can use as much as 112, so that probably explains the heat. To make matters worse, while I was crawling around behind my computer plugging and unplugging USB cables, the one connecting the Gefen adapter to my computer was physically hot--what I mean is, the head of the cable that was plugged into the back of my computer was warm to the touch, especially compared to the one next to it that only feeds a hub with printer, keyboard, etc. This would lead me to believe that it is carrying some sort of power signal as well. The good thing however, is that once I used the USB cable to change the "geometry" settings of the second monitor, I shut down, unplugged it, and started it back up and it retained the settings I had made. So there is no need to keep the USB plugged in constantly.

I wonder how much power is too much for the Gefen device itself, were I to try and find a replacement power supply.

Anyway, that's the report so far!

Awesome news on the picture and about being able to use the control panel.

As far as the hot USB cable goes: USB pinouts show that it carries +5VDC. However the ADC only carries 3 of the 4 USB signals, and those are Data+, Data-, and Data Return. So why that USB cable was hot is a bit of a mystery right now.

As far as the hot power supply goes: yes, the power supply would just be for the monitor. I am sure there is little inside the adapter itself aside from signals running from pin A to pin B; just a wiring job.

Here is one possibility for fixing the inadequate power problem:

http://www.electronicsurplus.com/commerce/catalog/product.jsp?product_id=71352

shows a new (old stock) Vicor switching power supply that delivers 28VDC at up to 5.4 amps.

I just bought one of these units (for $49+shipping from Cleveland) and was expecting to get a bare circuit board. I was pleasantly surprised to discover a high quality USA-made unit in an enclosure. What I will have to do is: add one jumper to set the input to 110VAC (unit arrives set up for 220) and add an AC power cord. They supply a wiring diagram so with care it should be pretty easy. Then I would just have to figure out the polarity on the power connector that plugs into the Gefen. This would be easy with a multi-meter. Now, ideally, I would be able to go to my local electronics store and get another of these connectors. Yeah, right... or just cut off the cable and wire it up to the new Vicor power supply. This would supply more than adequate power.

but I ran across this thread via a Google.

I've got a similar situation:

I'd like to use one of the 17" ADC CRTs on an old Bondi iMac that's been upgraded to a G3/600 Harmoni when the tube died and I started putting it into a steel cube the people at work were kind enough to punch for me. (Not finished with it - it's powder-coated bright yellow. Hence my username. I still have to dremel holes and slots.)

Anyway I got the monitor for about $50 and a Gefen VGA->ADC box for about $89 off of E-Bay. Needless to say it doesn't work because the box doesn't pass the analog signal to the monitor.

Looking at the VGA and ADC pinouts it doesn't look like it would be too hard to pass the analog signals and the DDC info from one connector to another. The power as everyone pointed out here is fairly easily doable via external supply. Not sure how the "soft power" works though. (It's interesting to note that Gefen technical support told me it would be too "technically complicated" to pass the analog signal. Yeah. Right.)

So my questions are this:

1) Do you have to use the USB to control the settings of the monitor in this case or will the DDC info do it? Or amy I misunderstanding what DDC does?

2) Where in the heck would I be able to find ADC connectors to experiment with? I'd like to keep the original monitor cord intact if possible but that might be a pipe dream for these kinds of projects.

3) Am I nuts for even wanting to try this?

Sorry for all the wordyness here but you guys seem to be the only thread I've found on this subject that is close to what I want to do!

YellowCube

AFAIK. the settings on these monitors are done through USB. If you do not have USB hooked up the Monitors Preferences Pane just reports a generic VGA monitor, I believe.

I think what you should consider doing is to sell that Gefen VGA->ADC adapter and get the Gefen DVI->ADC adapter and a VGA->DVI cable with male connector on the DVI end and the appropriate one on the VGA end. That would be practically plug-and-play aside from the power supply issues.

Check the postings from wallygeorge above.

AFA getting ADC connectors -- good luck -- I searched for a couple of hours and one can get various cables but the connectors themselves are hidden somewhere I didn't get to. Probably have to get them from Taiwan mfr or distributor who may not be too interested in selling only one or two.

Sounds like it will be a cool computer when done. Love the way these old Macs never die.

DDC allows the monitor to inform the video card what modes it's capable of, and allows the video card to send power management signals to the monitor. That's it. It doesn't include extensions for geometry control, etc. So yes, you need the USB plug.

Just as an aside, a Bondi iMac doesn't use DDC at all. Its video port uses a subset of the old "sense line" layout used on Beige Macintoshes. The reason a monitor attached to one via a "multisync" adaptar is able to "sleep" is that VESA compliant monitors go into standby mode when they lose sync for more then a few seconds. (Which happens when the video output is shut off.)

--Peace

AFAIK. the settings on these monitors are done through USB. If you do not have USB hooked up the Monitors Preferences Pane just reports a generic VGA monitor, I believe.

I think what you should consider doing is to sell that Gefen VGA->ADC adapter and get the Gefen DVI->ADC adapter and a VGA->DVI cable with male connector on the DVI end and the appropriate one on the VGA end. That would be practically plug-and-play aside from the power supply issues.

Hmm...so then it's possible that I could convince the thing to operate properly by plugging two Macs in temporarily - one to run the USB config and the other to test if I get a picture.

I still can't see how Gefen told me that it was "too complex" to get working. I suspect it just wasn't profitable. You'd think people in a specialized market would look more closely at something like this.

I really want to play with this so I'm seriously considering finding one of the ADC video cards and desoldering the connector to play with it on a custom board.

YellowCube

DDC allows the monitor to inform the video card what modes it’s capable of, and allows the video card to send power management signals to the monitor. That’s it. It doesn’t include extensions for geometry control, etc. So yes, you need the USB plug.

Confirmation is always good. ;-) Thanks!

Just as an aside, a Bondi iMac doesn’t use DDC at all. Its video port uses a subset of the old “sense line� layout used on Beige Macintoshes. The reason a monitor attached to one via a “multisync� adaptar is able to “sleep� is that VESA compliant monitors go into standby mode when they lose sync for more then a few seconds. (Which happens when the video output is shut off.)

So if I can set the Gefen box to the right resolution is should work provided I can pass the analog somehow.

As for the VESA/DDC stuff on the Bondi - I didn't know that. Thanks for the info.

YellowCube

Is this the thing you're using?

http://www.gefen.com/kvm/product.jsp?prod_id=1301

In which case, well.. Gefen is right... from a certain point of view. It sort of reminds me of the Star Trek episode with NOMAD.

"Non-sequitor. Your facts are uncoordinated."

That box is essentially an analog to digital LCD controller. All the circuitry in it is designed to digitize an incoming VGA signal and send the data to a digital ADC monitor. Using it to drive an *analog* monitor is simply outside the design parameters.

(After all, what would be the point of digitizing an incoming signal just to output the signal again *to an analog monitor*? You'd need another set of D/A-A/D converters.)

All you need is a cable adapter and a power supply. And the power supply will have to be bigger then the one supplied with the Gefen box anyway.

I still stand by my argument that the "right" thing to do is to cut the end off the cable and solder on a VGA plug, a USB plug, and a line to the power supply of your choice. Once you've done that, it's, well, done, and it'll work with *any* computer. And it'll cost you about $7 in parts, outside the power supply. (Which will be a little pricey, unless you find one surplus.)

--Peace

And I'm sure you're quite correct about analog being outside the design parameters.

The thing that bugs me is that it would take very little to pass the signal through and beef the power supply in the design process to support the monitor. Then they could have supported all of the monitors not just the LCDs and sold to a wider audience, granted not that much wider but still, and thus made more money.

Regardless thanks for the suggestions and help.

I think my final course of action here is that I don't want to cut the monitor cord. What I'm going to try and do is find a dead ADC video card, remove the connector, and make my own adapter cable. As for power supplies there are a few out there from different places that should support 28V, 5a without too much trouble.

YellowCube
(Typed on the guts of said iMac while dremeling the metal of the yellow cube. ;-)

Are yuo sure that analog signal on ADC is the same as on VGA?

Sorry for dredging up this old topic but....

1) I found a source for ADC connectors: http://www.surplussales.com/Connectors/Video-Data.html

2) I **almost** have this working by building my own connector from basic components. (soldering a VGA connector to an ADC connector and adding 28VDC power.

3) Once I figure out the last puzzle, I can post all the pinouts needed to make this work.

My biggest frustration right now is, although I can power up the monitor, have it recognized by my Powerbook, and begin to display an image; my Powerbook shuts down five seconds after connecting the display. It appears that the Powerbook is being sent a "soft-power off" signal (like holding the power button down) via the DVI port!!! I didn't even think this was possible. I'm even getting an "Are your sure your want to shut down your computer now?" dialog before the Mac turns off.

If anyone can tell me why this might be occurring, I'd probably have this working and for VERY little investment. The other question is what power is sent to the LEDs to power the button lights on the display, I don't have those working yet either. I know what pins they're on, just not where they get their power and how much it is.

Thanks for this great thread.

Abc

I have taken this hack as far as it can go, and while it was a sucess in that I have a working solution, it is a failure in that it will not meet my needs. I'm documenting it here in case others find it of some value.

My original goal was to produce a hack that would allow me to hook the 17 inch CRT/ADC Studio Display up to a KVM where it could be used by both my (non-ADC) Mac and a PC. My solution was to construct a conversion box with an ADC connector for the display; VGA and USB connectors to run to the KVM; and 28VDC power supply for the monitor.

The ADC connector was aquired here: http://www.surplussales.com/Connectors/Video-Data.html

The VGA connector and project housing was from a gutted VGA A/B switch that I had on hand. This was convenient since this provided three presoldered VGA jacks. All I needed to do was choose one and solder the right wires to the ADC connector.

The power supply was going to come from here, http://www.electronicsurplus.com/commerce/catalog/product.jsp?product_id=71352 , based on a tip from a previous poster, but since the project did not meet my needs, I made do with a borrowed power supply for testing purposes.

The ADC pinout is available on Apple's web site, http://developer.apple.com/documentation/Hardware/Developer_Notes/Macintosh_CPUs-G5/PowerMacG5/3Input-Output/chapter_4_section_12.html , and here is how I connected the pins using point to point soldering:

ADC pin / connection (NC=No Connection)
--------------------

1 / +25VDC
2 / +25VDC (yes, there are two 25V connections. that's a lot of power)
3 / NC
4 / NC
5 / NC
6 / NC
7 / NC
8 / NC
9 / VGA pin 12 (DDC Data)
10 / VGA pin 14 (Vsync)
11 / 25VDC Ground
12 / 25VDC Ground
13 / NC
14 / NC
15 / NC
16 / NC
17 / NC
18 / NC
19 / VGA pin 15 (DDC Clock)
20 / Ground
21 / USB Data+
22 / USB Data-
23 / USB Ground
24 / NC
25 / NC
26 / NC
27 / NC
28 / NC
29 / NC
30 / NC
C1 / VGA Pin 3 (Blue)
C2 / VGA Pin 2 (Green)
C3 / VGA Pin 13 (Horizontal Sync)
C4 / VGA Pin 1 (Red)
C5 / Ground and VGA pins 6, 7, and 8 (RGB Ground)
Sheild / Ground

These connections should give you a working solution for the Studio Display with the following caveats:

As I quickly found out once I had this up and running, the 17 inch CRT/ADC studio display does not support VGA video timings and only two VESA video timings, 1280x1024 and 1600x1200. Since it cannot output 640x480 VGA, no image will be visible during the PCs "post" period. Furthermore, my PC video card did not support the bizzarro timings and resolutions Apple provided for this display:
http://docs.info.apple.com/article.html?artnum=58673
... even after I created custom resolutions for them.

My own fault, I suppose. RTFM next time.

The only other issue was that, although everything worked fine for my desktop mac and PC, connecting it to my Ai Powerbook via a DVI to VGA adapter made my PowerBook turn off as if someone was holding down the Power button. I didn't bother to try to figure that one out.

If any one can find something I overlooked, especially if you have a solution to run this display at industry standard timings, I'd love to hear about it.

Cheers,
abc

In all the internet, it seems that this one post has made any headway into doing something, anything with the beautiful 17" Studio Display CRT ADC. If nothing else, I hope you know this!

I found this thread because I want to do (yes, I know) the unthinkable... connect my clear-backed beauty to an iMac g5 (2.1 ghz). I know that this is impossible, but I was just posting on the off chance that anyone had found hacking Nirvana--no dangerous fire hazards, no creepy connections, just a stable connection- with this situation and just wasn't telling.

Do I actually have to buy a Cube just to use the monitor? It was a gift, it's never been opened, and I know that it's only worth 60 clams on ebay, but jeez! I think that they display one of these monitors at MOMA, for Pete's sake! I'd rather have this monitor than a Monet! ...well, maybe not. But you get my point!

What do I have to cut and rend and splice to make this work? Could someone just make an iMovie how-to? I'd buy it for $1.99 on iTunes!

Many thanks!

It seems to me like Eudi's suggestion of just cutting the plug off and putting on a suitable power, USB and VGA connector set was the most sensible... but nobody really followed it up. Perhaps that's the one to try?

Given that Surplus Sales sells ADC jacks for $3, you could still follow this approach without hacking up the built-in cable.

I know this is extreme, but after having bought a second one of these babies, I think we should take the monitor and throw it through the window of an apple store in protest! It is absolutely ridiculous that they don't support this and that they make no effort in telling the public this. I think it is fraud. If I ever heard. Geez they say in the manual that it supports two displays and a normal consumer would expect to have identical monitors! Absolutely crazy if you have a car they have recalls for years and they still will get a hold of you , but a fine company like apple to stand beside their product. I'm disturbed by all the effort one has to go through to find any answers on this subject on such an easy to fix solution so they go on defrauding consumers years in the future after the fact by not informing the cosumer by puttig at least a basic explanation on their website or at least a technician that will give you a straight answer instead of asking for $50. for it. I am so disgusted by this.

Once again, I challenge someone to actually try Eudi's fairly simple idea either by modifying the cable or as Tom said just buying a connector and making the adapter. It wouldn't take more than a few hours and the results would clearly benefit a lot of people.

If someone wants to donate me one of those fine monitors and a connector I'll gladly spare 3 hours of my precious time to do it

Michael, I'd give you $50 (the price of the monitor on ebay) to make me an adapter that worked. That'd be a whole lot less than the close to $300 it would take to get the Gefen box, the cable, and the power supply...

Here's what I propose. Buy me a monitor, and all the parts. And _if_ I can make it work, you get a schematic. This deal, she suits me fine.

In short, I don't really have the time or money to mess with it. But it doesn't sound all that difficult! I'm sure someone should be able to try it.

Edit: Keep in mind also that you'd need a 25v DC power supply, which isn't exactly common but shouldn't be impossible to find.

I have the same dual monitor problem and of course found out too late. I think a different approach would be is to have the other monitor hook up to the same video card, but by adding another AGP port and from there figuring how to get the computer to work with the second AGP port and to properly power it, and if needed software to tell the computer how to act with it. This way your getting a legit signal that is made to work with that monitor and probably would be an easier harware wire jog. Let me know what you think?...Mark

Hi there,

I started to connect my 17" CRT Studio display (7768) to a PC. As I have only an imac without external video connector, I cannot test the unit with a mac yet. I bought an used apple cube power supply and grabbed the adc connector from an used video-board.
DDC connectivity is tested with Linux as well as USB and both work. But I do not get any image. Do I have to switch the monitor on with another mac? I tested several video modes but non worked. ddcprobe reports a VESA mode of 800x600 at 72Hz to be working which I tried with 8 bbp but no response. So I am stranded here. Any thoughts?

gerald

Check the level on the power on pin, I've tried my CRT with a Gefen
ADC adaptor box which brings in USB and power and the monitor will
not power up even if a VGA signal is present on the DVI-I connector.

Hi Starman,

thank you for your comment, although this thread seems to be a liitle dead now!
I may be wrong but I got the impression that the power switch on the crt display just shortens the power signal to ground. This could mean that the G4 is started by grounding it's internal 5V level to give him a power up signal.

Assuming the PC also use 5V for it I could test this by using the PC's power on connectors and try to start the PC by pressing the monitor's start button. Maybe I'll give this a try the next days.

I'll keep you informed,

Gerald

I'm still interested in this because I have a Cube and 2 of the CRT's
I still think they look good, even though I use Dell 20" LCDs on
all my other machines. I have a GF2 Twinhead in my Cube that I'd like
to run with 2 CRT's. I got the Gefen DVI->ADC box , it comes with a
Cube 28V supply, good for running two monitors (28V@8A) but it
wont start up the ADC17 CRT, All the video signals run through it, but
it must not be handling the power up or maybe a Sync signal.

I did connect the power line with the positive connector of the soft power switch of my PC and I could start the PC when pressing the button on the monitor. But I haven't tried to get the monitor working due to the lack of time. I read somewhere that the monitor likes to have a sync-on-green signal but I cannot remember where. To be continued..

Gerald

bought a switching power supply for modification year ago.
just got a chance to sell the beautiful monitor away.
thinking of selling the power supply away since no use for me...
28V 5A DC out/ 110V or 220V AC in selectable.
15USD... before shipping....
email me if interested... makuang at mac.com

Cheers
Ma

I can't believe that in the several years since this was posted and the solution pointed out several times than nobody actually tried it. I might buy one of these monitors and have at it just because I like how they look :^)

Couldn't agree more. Has anyone yet been able to get the lovely 17" CRT display going, bypassing the adc connector?

I would like to try converting my Apple adc 17" CRT monitor for use on an ordinary VGA connection, so would appreciate any information available. I will post the conversion details back here for everyone to read.
bbj

Point being, most of the cheap LCD monitors you can today on Newegg or Tiger Direct, are now better than these ADC connected Studio Displays made a few years ago. The only thing missing is the great design. So... a better hack if you like style would just be to mod the case and fit it with the guts of a cheap LG or AOC.

I have an ADC 17" CRT studio display (the one with the clear case) Got it with my old mac cube. I want to use it for a second monotor for my new Imac (pentium core duo).

Here is what I am thinking of trying:

1) Get a gefen DVI to ADC adaptor (Apple's DVI to ADC adaptor does not pass through the analog signal - dosent have the analog pins)

2) Use th power supply from my old mac cube instead of the power supply that comes with the gefen DVI to ADC adaptor (the Gefen power supply is not powerful enough)

3) Use a DVI-I cable between the Gefen converter box and the computer (the DVI cable that comes with the gefen DVI to ADC adaptor does not pass through the analog signal - Must use DVI-I cable)

4) Use a mini DVI to DVI adaptor at the end of the DVI-I cable to plug it into the mini DVI plug on the new Imac (pentium core duo)

QUESTIONS:

Does anyone think this will work (or not work)

Will the mini DVI to DVI adaptor pass through the analog signal?

all coments / opinions would be appreciated

SnakeNY

I hooked up an ADC 17" Studio Display CRT to my PC a few months ago and I've been using it since then. It works fine for me, though not without a few oddities. I'm posting this here to help anyone else trying a similar operation, since the internets seem to be empty of relevant info.

Basically, I did the most obvious thing; I looked at the pin out diagrams for the ADC and VGA connectors (use google, easy to find), chopped off the ends of the monitor's cable and an old VGA cable, and connected the corresponding wires. You will probably need a multimeter or tester to see what wires correspond to pins.

When connecting the wires, watch out on the R/G/B signal wires. The R/G/B ground wires are wrapped around the actual signal wires so be careful that you don't short the signal and ground.

For power, I used the actual PSU from a dead G4. I had one on hand and it was absolutely certain that it would provide the proper power output. I stuck a paper clip between the green and ground pins on the motherboard power connector to force the PSU to stay on at all times and then connected the 28V output from the same connector (they are black and white, near the end, look up pin out) to the power line from the ADC cable.

I also hooked up the ADC cable's USB connectors to a cut USB cable. Since the monitor has its own power the USB's power line isn't used.

When I initially hooked up this setup to my computer, it wasn't working at all. I spent many hours trying to troubleshoot, with no luck. The computer could detect that the screen was connected, reporting DDC info such as the resolutions/refresh rates supported and the name of the monitor, but it wouldn't wake up. So in desperation I tried hooking it to my friend's G5, and as soon as we hit 'Detect Displays' it woke up with a nice bright picture.

I have no idea why the Mac OS display manager is able to activate it and Windows (using either an ati or nvidia setup) can't, so I'm still investigating that. In any case, once the Mac OS machine has caused the monitor to activate, you can unplug it from the Mac and into your PC and the PC will output to it fine as long as the monitor is hooked up to power. If it loses power, it has to be hooked to a Mac again to wake it up. Any Mac so far has worked, but no PC... I'll figure it out eventually.

So anyway, once it's activated and hooked to a PC, it works fairly normally. The supported resolutions are fairly restricted (as the other person who tried this said, it can't output at the resolution the computer boots at so you won't get video until the OS loads). I've been using 1152, 1280, and 1600 resolutions and I think the settings most people would need apart from OS installation/configuration/troubleshooting time are available. In those cases, you'll need some kind of backup screen to use until you can get one of the supported resolutions.

As for the USB hub, it's not recognized in Windows, but it works in Mac OS. You need to hook it to a Mac system with USB if you want to adjust the monitor properties such as picture size/brightness/etc.

I got another of these monitors yesterday so I'm going to try converting it as well, so then I can have the only setup in the world of dual ADC studio display CRTs hooked to a Windows PC ^^; If there's anything different about the operation, I'll post what happens. Anyway, I hope this was helpful to someone.

I bought a cube instead and plugged the crt in there. You can definitely see, once the mouse flashes on USB detection, the monitor also starts. I am quite sure the monitor is controlled via USB so once it is set up and powered you are fine. But I bought a TFT instead and will sell the crt on ebay. Thank you all for your help and comments.

I managed to get my hands on 2 Cinema Displays. 1x 22" and 1x 23" HD. They are the acrylic Cinema Displays with the ADC connector.

My goal is to use them with my PC with Dual DVI. My PC also has PCI-E video. I do have 2 of the Adapter Power Supplies. I've found a way to build my own power supply that will run each monitor with filtered and smooth & constant power. However, I have 2 problems:

#1 - I don't have 2 female ADC connectors. I'm not about to rip open the 2 adapters I currently have. I'd like to sell those back on eBay. I've been searching for 'as-is' cards or non-functional cards for pennies on the dollar as I only want the female ADC connector. I've only been able to find good functioning cards online. Many not as low cost as I would like. I feel $20+ for a "working" card is a bit much when all I need is the connector. Seems a shame to ruin a good card when someone else might actually need it. But my hands are tied on this one.

#2 - I can't shut the monitors off using the DVI connection. I leave my PC on, and some programs are sensitive enough when running that when the screen saver pops up, it can cause errors. While minor, they do show up. On other displays, I just push the power button and it shuts off. >>Not with the ADC monitors. ADC monitors are controlled through the system, or would be if it were a Mac.....pretty much ALL functions would be. Even though my panels have buttons that, I would guess, normally do something when connected to an ADC video card on a Mac, but do nothing when connected to DVI through the converter box. What I'm planning on doing is create a switch that cuts the power to just the panels, and still leaves the USB ports running.

I've also run measurements on the USB for the monitors. The USB is v1.1, and I've found a 2-port v2.0 hub with a small enough circuit board that can fit nicely in the Cinema Display cases. I'm able to rewire to the hub's board and have the USB be the full v2.0 to give me the higher speeds. The acrylic style displays actually have a bit of working room that comes in really handy for such work.

In short, I'll have a box with 2x DVI ports in, 2 ADC ports out, a switch to shut the monitors off (maybe 2 to shut off each monitor independently), and a connection for USB. Not sure how soon I'll have it all finished out, as I am still looking for a few parts. And I'm trying to keep total cord length on the new PSU adapter unit to less than 40cm or 16".

Wish me luck.