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Yeah, I'm having massive image loading issues with the previous page of this thread. Holering's, and the most recent poster, for example.

I actually took mine down. You can notice this on the ones that say broken. Imgur.com has worked great for me otherwise.

Been testing a Hercules clone card, here are some screenshots from an IBM 5151 😀

It's still pretty bright, too 😀

Must say it's really hard to take any decent pictures of this. My camera just won't capture this beautiful deep "radioactive green" colour. With white balance on sun or cloudy I seem to get the best results, and even then the pictures look more like bright yellow if you compare them side by side with the monitor. It looks pretty blurry on camera too, while in reality this tube draws some razor-sharp lines.

Some more pics:
http://i.imgur.com/RX5xXHb.jpg
http://i.imgur.com/rSNshHz.jpg
http://i.imgur.com/OGFi185.jpg

How does your 5150 have a Pentium II? 🤣

Err, I meant to say 5151 of course 🤣

formatting floppies turned out more difficult than expected so I just plugged the Hercules card in the P2 😉

"Infinite RGB" holering? I think not. 😉

In an analogue signal, small variations are indistinguishable from noise and distortion, giving you a practical limit on measurably different values.

That's even before you consider that image going in to your video card's RAMDAC has a fixed number of possible levels per channel.

In theory, "analogue" represents an infinite number of values between two points, but in practice that's utterly unattainable.

jwt27 wrote:

Been testing a Hercules clone card, here are some screenshots from an IBM 5150 😀

It's still pretty bright, too 😀

Must say it's really hard to take any decent pictures of this. My camera just won't capture this beautiful deep "radioactive green" colour.

Wow that's great! That really does look like you're on a spaceship or something. Must've found that thing on a forgotten galaxy or wrecked ship or something. Are they all green like that?!

EDIT:
Just got this for $5.00:

Apple Multiscan 15 Display 1994. Supposedly it works (seller had shots of it working) and I have the db-15 to VGA dsub adapter, but it refuses to show anything (light stays orange. Only tested with PC). It's really nice that it has built-in stereo speakers. This would probably go great with NES, SNES, Saturn, and other pre 128-bit game consoles. Despite what I said earlier about IDC-3000 making NES cvbs rgb like, that's not true. NES doesn't put out a standard NTSC signal (idc-3000 is extremely picky about that) so 3D y/c seperation wouldn't turn on (manually forcing it on didn't work either); it simply doubled 240P without y/c separation.

Holering wrote:

Apple Multiscan 15 Display 1994. Supposedly it works (seller had shots of it working) and I have the db-15 to VGA dsub adapter, but it refuses to show anything (light stays orange. Only tested with PC).

What software? AFAIK Apple Multiscans don't support the 720x400 VGA text mode, so you'd need to fire up Windows or something that runs at 640x480 or one of the other supported resolutions:

http://www.everymac.com/monitors/apple/multip … le_scan_15.html

The Apple Multiscan was likely made by NEC. I have seen the same monitor sans the Apple logo with standard VGA input. Its likely not a resolution problem, but an adapter problem. Some Mac monitors require various sense pins to be connected and some might even be Sync-on-green instead of separate H+V sync like VGA normally uses.

Regarding text mode, any VGA monitor should support it. IBM's original 8512 and 8513 VGA monitors for the PS/2 were fixed frequency. The horizontal scan rate of 720x400@70hz is the same as 640x480@60hz.

http://martin.hinner.info/vga/timing.html

The NES outputs 240p (288p in PAL), which most newer devices will complain about. Even with comb filtering, the composite output is lousy. Its better to mod the unit for RGB output and derive S-Video from it if you don't have the appropriate monitor.

Holering wrote:

Wow that's great! That really does look like you're on a spaceship or something. Must've found that thing on a forgotten galaxy or wrecked ship or something. Are they all green like that?!

It sure has its 80's sci-fi charms 😀
This particular Hercules clone has an another cool effect by the way: when switching between graphics and text modes, it "glitches out" for a moment and dumps random Matrix-like characters across the screen, and then takes about a second for the picture to stabilize. I thought that's pretty cool, something you'd expect to see only in sci-fi films. Maybe all Hercules cards do this but I have no other (working) cards to compare. I made a video of it, will see if I can convert it to a gif or something. In the meantime, here's a still frame to show what I mean:

And yes, all 5151 monitors have this slow, green P39 phosphor. I found chromaticity values for this phosphor online; turns out it's way outside the normal sRGB colour spectrum. No wonder my camera won't capture that... and even if it did, no one would have a monitor to show it anyway. I'd say just get one, even if not very useful these are some great screens just to stare at once in a while 🤣

Took a few more pictures at low contrast yesterday, and managed to capture some sharp scanlines:

And another: http://i.imgur.com/I1Hb6jS.jpg
Bright text in daylight: http://i.imgur.com/TLqbJis.jpg

Here's one taken on high ISO / long shutter time, to show how bright it is at max contrast... compare with the Eizo next to it: (and please don't mind the mess) http://i.imgur.com/nxJ1pEE.jpg

jwt27 wrote:

And yes, all 5151 monitors have this slow, green P39 phosphor. I found chromaticity values for this phosphor online; turns out it's way outside the normal sRGB colour spectrum. No wonder my camera won't capture that... and even if it did, no one would have a monitor to show it anyway. I'd say just get one, even if not very useful these are some great screens just to stare at once in a while 🤣

Hmm, that's interesting. How about a Sigma Foveon camera and AdobeRGB? 😁
Nah jk... I'm sure that green phosphor is much more awesome in the flesh. Green has always been the most difficult color to capture.

And whoa, that "Matrix" screen, now I know where the inspiration for the movie came from!

NJRoadfan wrote:

The Apple Multiscan was likely made by NEC. I have seen the same monitor sans the Apple logo with standard VGA input. Its likely […]
Show full quote

The Apple Multiscan was likely made by NEC. I have seen the same monitor sans the Apple logo with standard VGA input. Its likely not a resolution problem, but an adapter problem. Some Mac monitors require various sense pins to be connected and some might even be Sync-on-green instead of separate H+V sync like VGA normally uses.

Regarding text mode, any VGA monitor should support it. IBM's original 8512 and 8513 VGA monitors for the PS/2 were fixed frequency. The horizontal scan rate of 720x400@70hz is the same as 640x480@60hz.

http://martin.hinner.info/vga/timing.html

The NES outputs 240p (288p in PAL), which most newer devices will complain about. Even with comb filtering, the composite output is lousy. Its better to mod the unit for RGB output and derive S-Video from it if you don't have the appropriate monitor.

There's a lot of "should" in there... 😉

Remember this is something from Apple's super-proprietary era, I wouldn't be at all surprised if they've locked out anything but their Mac-compatible resolutions in firmware (or with some custom analogue circuitry perhaps).

That said: http://tim.id.au/laptops/apple/displays/multi … _15_display.pdf

The service manual seems to suggest it should work, supporting TTL level H+V sync as well as SoG, and sync ranges that should include VGA text mode at the very least.

*shrugs*

That green phosphor screen looks amazing. Must be really cool at night in a room with all the lights off...

I've used both an Apple Multi Scan 14 Display and a 15AV with various PCs and they behaved exactly like your bog standard multiscan PC monitor, had no problem displaying odd resolutions within the capabilities of the deflection system.

Apple computers care about the monitor sense lines (no video if you don't connect them) but the monitors don't. Make sure your adapter is routing the HSYNC and VSYNC signals from the VGA side into the correct pins on the Mac side. Some Apple monitors use CSYNC on a different pin and this won't work with your particular display.

Squall strife said: you'd need to fire up Windows or something that runs at 640x480 or one of the other supported resolution

Appreciate the help. I tried that (actually it was 640x480@60hz in Linux). Didn't work. My friend tried his line doubler and swapped HSYNC+VSYNC with SYNC and that didn't work. I'm thinking I'm going to need a new adapter.

Fixed shots in page 8.

The IBM 6325, also known as '15V' as per the label on the front was the last official Personal System/2 monitor--succeeded the 'grey faced' ones-- released with the last series of PS/2s (then after came the P and G series of CRTs, like the rather available P70). Windows 95 strangely even has a definition for this monitor built in by default.
You can see a stock photo of a model 56 here:

It's a decent CRT with anti-breathing, good contrast, and picture that isn't blurry. The anti-breathing feature is something that was dropped on a few later CRTs IBM made (due to the fact that mechanism is expensive, whatever it is). Oh, and physical controls with no virtual OSD.

So here is mine in action, unfortunately it recently developed a weird problem of two dark vertical lines, and some sort of shadow inversion...

I am under the impression it's some sort of passive component, like a tantum. That weird shadow effect fades with usage as it is left on-- and has slowly been gradually getting worse over the last few days. But never fear, I shall fix it!

Another cool feature of this CRT is the fact the power gets plugged into the base rather than at the back of the tube. And yes mine has the flippy panel still, it just got cut off in those photos. Flippy panels are important for your CRT experience...
My only complaint is that the brightness cannot go very high, so you're stuck with a lot of contrast. That's fine when you want true colour realism, but some DOS games require the gamma and brightness to be jacked up because they're made so dark... for some reason.

I'd say it's a failing electrolytic capacitor, located on from most to least likely:

• +200V supply for the cathodes
• B+ filter capacitor
• Main power supply capacitor

133MHz wrote:

I'd say it's a failing electrolytic capacitor, located on from most to least likely: […]
Show full quote

I'd say it's a failing electrolytic capacitor, located on from most to least likely:

• +200V supply for the cathodes
• B+ filter capacitor
• Main power supply capacitor

Thanks for the tip; I just got the thing apart (which was hideously difficult). I'll need to order some of the larger caps from digikey as I don't have them on hand. It would make sense if it was a capacitor as the problem gets less 'bad' as the CRT warms up, which is presuming the failing capacitor eventually gets a higher charge. I might replace some of the diodes on one of the PCBs that the coil's wires are connected to, just for the sake of it.

Quick question, do you know what might prevent a CRT from getting its VGA signal when the cable is good? My G70 would sometimes have a flickery screen. One day it started flickering now and again really bad. The next day, no picture.
CRT is pictured here:

I've already did a continuity test on the VGA cable, it's not bad. I also am able to get the monitor to flash the colour test lines very briefly, so I am under the impression the display logic is still okay.

I wish I knew more about CRTs on a hardware level, but unfortunately it's just not an area I am very well versed in. If I had to guess, it is a shorted passive near something that drives the VGA signal?

Wtf. 🤣 How can you live with icons scattered everywhere like that?! 🤣