Like many of these proprietary displays it may well integrate as apart of the terminal

In any event it may not actually be a terminal

http://www.vcfed.org/forum/showthread.php?544 … -monitors/page2

6300 stuff can be hard to fire off without a matching video card (25khz bleh)

https://allpinouts.org/pinouts/connectors/com … t-pc6300-video/

Anyway
Some of the IBM ATM screens lacked a mains power cable and ran off DC and accepted ASCII input for display instead of a video signal.

When you turn it on do you get a big bright screen or a cursor?

Depending on what you find inside the screen you may need to hardwire to the driver rails inside the screen, the mda screens typically all had similar scan and sweep rates so it should be possible to drive 15khz CGa or MDA rates depending if it’s a NTSC/video setup or strictly mda like.

Good Luck

rmay635703 wrote on 2021-03-14, 18:43:

Anyway Some of the IBM ATM screens lacked a mains power cable and ran off DC and accepted ASCII input for display instead of a […]
Show full quote

Anyway
Some of the IBM ATM screens lacked a mains power cable and ran off DC and accepted ASCII input for display instead of a video signal.

When you turn it on do you get a big bright screen or a cursor?

Depending on what you find inside the screen you may need to hardwire to the driver rails inside the screen, the mda screens typically all had similar scan and sweep rates so it should be possible to drive 15khz CGa or MDA rates depending if it’s a NTSC/video setup or strictly mda like.

I'm kinda hoping this can be driven with MDA or CGA. There is no separate power cord and it doesn't appear as though there was one - there is one empty hole on back, but seems too small to have been for a power cord. I guess I have to open it up.

The AT&T Link was helpful. The missing pins on mine are 2, 8-10, 12,-15, 22, and 23. That corresponds to Monitor ID 1 and DeGauss with the remainder either being either NC or GND. I suspect that's probably a reliable map for those pins - should help when I start looking inside.

Yeah, that 25-pin connector looks familiar. The Olivetti M24 (and by definition the AT&T 6300) had a proprietary 25-pin video connector like that.

As for the pinouts, through some Googling you can find a wiring scheme to make a 25-pin to 9-pin conversion cable. That's the relatively easy part.

However, like rmay635703 mentioned, such monitors require a 25kHz signal, which most regular graphics cards can't provide. The ATI EGA Wonder 800 (I believe the regular 800, not the 800 Plus, but I'm not sure) is one of them. It has a specific jumper for supporting the 25kHz signal output required by these monitors. The STB Multires was another card that offered such support. See https://stason.org/TULARC/pc/graphics-cards/S … ALLEL-PORT.html (Apparently 25kHz alone isn't enough, it also has to be an inverted signal?)

If you ever get your hands on an STB Multires (or Multi Res, with a space in the name?), be careful with that on-board "parallel port". If it's indeed a parallel port, you should *not* connect the monitor to it (even though the connector fits directly in it), but you instead need to make the aforementioned 25-pin to 9-pin conversion cable and connect the monitor to the 9-pin port. However, it might not be a parallel port, but in fact a 25-pin port meant specifically to accommodate Olivetti/AT&T monitors, and the documentation on stason.org may have misidentified it as a parallel port. Try to find the manual on-line to get clarity on that!

These monitors are quite rare, though. So if you can't get it to work, I'm sure someone here or on VCFED will gladly take it off your hands!

Oh, and if it doesn't have a separate power cord, then it's most likely a monochrome monitor. The color monitors with the same interface do have a separate power cord. Apparently the 25-pin connector includes power pins that provide enough power to drive a monochrome monitor, but not a color monitor. So I guess you'd have to inject the right voltage into the connector, on the specific pins on which the monitor expects to receive power. Better be extra careful not to mix the pins up.

Thanks for the tips. And I figured it was probably powered on the DB25 - I would have been very surprised if this thing ended up being a color display. I'm kinda curious to crack it open and check it out if I can find some time, though.

Back in the day, I was given a digital wedge monitor and a visit to digital dealer yielded information. All I had was supply 12V and composite signal to this monitor.

This could be similar concept?

Cheers,