Conversion of NeXT color video signal

[grog]

As limited space requires maximizing system-to-display ratio, I have several NeXT systems pushing their color video signals through passive VGA switches to capable multisync monitors. However, I would like to eliminate the VGA switches and be able to connect these display connections to Raritan MasterConsole (II or Digital) KVM switches instead. Unfortunately, the Raritan switches are rated for specific, garden variety Super VGA & HD signals (presumably for OSD menu support) and struggle with the resolution and/or refresh rate unique to the MegaPixel color signal.

Is there any device analogous to a GBS8200 that can convert the 1120 × 832 @ 68 Hz format into a more industry standard resolution and refresh rate?

 

[Eudimorphodon]

Raritan MasterConsole (II or Digital) KVM switches

Sorry, but I can't help myself.

(Twenty years ago I fought tooth and nail to get a stingy company to invest in a metric buttload's worth of Raritan's CAT5 KVM products for our a engineering labs. The idea of having one of those at home... I guess isn't that unrealistic anymore given what they seem to be selling for on eBay? Huh. Sad.)

The KVM in question here is a "local" one, right, not the IP enabled models? (IE, one that relies on fully digitizing the signal, all bets are off there.) Off the top of my head I can't think of a great reason why the Raritan would *prevent* it from working with a (fairly arbitrary) signal even if the OSD had problems locking onto it? Granted, well, it's been 20 years. The monitor you have hooked up to the headend as the console can otherwise handle the input?

... That said, I'm wondering looking at Raritan's website if the "digital" line of products they have now relies on carrying stuff back to the head-end from the nodes in the form of something like single-link DVI, IE, the "VGA" host modules are incorporating a digizing chip like you'd find in those VGA-to-HDMI adapters. That might well be a deal killer.

 

[grog]

Edui-Wan (and others in the fallen Raritan Order):

All the gear I have is indeed not-over-IP "local" KVM switches, cables, and adapters. The monitor on the headend is a Sun X7136A 21" Sony Trinitron CRT which can handle almost any signal you can throw at it, including the NeXT color signals from a Sound Box NeXTStation (Turbo) Color or Dimension board. The passive hardwired VGA switches work since they don't modify the signal in any way.

I ended up inheriting an MCC8 switch decades ago with just enough parts to integrate my hardware at the time. Eventually the vintage collection started taking off about ten years ago and so followed the accompanying, now embarrassingly-large Raritan MasterConsole II "network" of multiple switches, Guardians, etc. With the right adapters, almost everything with PS/2, ADB, Sun, AT, serial, USB or Amiga peripherals is controlled from a single keyboard and mouse. Similarly, almost all non-digital video can be converted to VGA. So short of Apollo Domain, HP-HIL Apollo, and NeXT, there is one console to rule them all. (The wife has helped me scoop up almost all the cheap Raritan MC II cabling off eBay in recent years and I've squirreled away enough of the CCP(T) wiring to facilitate expansion for years to come.)

I went the other extreme when a cheap MasterControl Digital switch became available during the pandemic, not being aware until afterward the dongles are normally ridiculously expensive and the MCD is not backwards compatible with the previous generations of Raritan. In time I've found enough deals to affordably get the modern digital video + USB systems hooked in, augmented in places by IOGEAR digital KVMs. Comparing the slightly washed-out MCD video signal quality on the headend Sun AI24PO 24" DVI display compared to those attached via IOGEAR, I'm not entirely convinced Raritan MCD truly operates exclusively in the digital domain end-to-end; if it's not, that makes it about the same value as a Dominion setup... except in black.

Bringing this back to the NeXT World...

The MCD VGA cables MDUTP[20,40,60] have a inline blob of A2D logic to convert the video signal to Raritan's proprietary 8-wire digital blend of eleven herbs and spices. For almost any computer system the cable seems to respect the normal laws of an analog VGA signal, but again, it seems to only like the standard Super VGA resolutions at specific refresh rates. Whether or not the MDUTP uses standard VGA-HDMI digitization as suggested or something unique to the MCD is something only Raritan knows. I've tried attaching the VGA end of the MDUTP through a DB-13W3 adapter to the NeXT and I get a dizzying image that reeks of some horizontal sync failure. It is, strangely, almost identical in quality to the video I see when attempting the same method on the beige MC II analog video switches. My armchair OSD theory remains grounded in the observation that Raritan wants something familiar to latch onto to do its thing, and if it can't, it doesn't feel it's necessary to allow the signal through to the other side intact.

If the MCD had been able to sample the analog NeXT video into something usable I'd be using MDUTPs plus some Wombat ADB-USB and Drakware NeXTUSB adapters. I still am hopeful I can find some resampling/rescaling device to feed the KVM switch something it likes, hence the original post. But maybe things just don't work that way.

 

[grog]

...I guess that makes me wonder if there is a highly-capable analog-to-digital video adapter out there that can convert the NeXT video signal into something HDMI-safe and in turn be connected to an MDCIM dongle. That would probably solve the problem.

 

[Eudimorphodon]

Edui-Wan (and others in the fallen Raritan Order):

They were an elegant weapon, for a more civilized age.

I feel Alec Guinnesss-level old now. The first Raritans I was able to get into the lab were the daisy-chained 2002-era Z-series. We were so cheap that for a while I had some Z-series nodes sitting on the console ports of the hateful rack-mounted Belkin KVMs we were buying before, thus allowing you to descend into madness by channeling input-switching keystrokes for the Belkins through the Raritans. Eventually we were able to upgrade to a full-on Paragon setup, although even then for maximum cheapness we had keep using all the Z-series modules we'd already bought until the engineers whined loudly enough to management about how one user being on the chain locked out all the other machines on that chain until they were done...

The MCD VGA cables MDUTP[20,40,60] have a inline blob of A2D logic to convert the video signal to Raritan's proprietary 8-wire digital blend of eleven herbs and spices. For almost any computer system the cable seems to respect the normal laws of an analog VGA signal, but again, it seems to only like the standard Super VGA resolutions at specific refresh rates. Whether or not the MDUTP uses standard VGA-HDMI digitization as suggested or something unique to the MCD is something only Raritan knows.

For laughs I opened up a manual for the old Paragon series, and those seem to have used an analog format for hauling video across the Cat5 wiring, but from digging around more it's fair to say that Raritan has always been more than a little cagy about *exactly* what the heck they're doing; with the newer models I genuinely have no idea if their "digital" CIMs convert video to analog, if their modern analog ones convert to digital, or if the head-end natively accepts both. (Ran across a postively head-spinning CIM compatibility matrix that definitely didn't help, other than make it clear that the Paragon I CIMs haven't been supported for... a while, but there was in fact a weird period where some of them *were* supported by some of the more modern headends until software version x.y.z...) So... yeah. My knowledge of the old ways almost definitely does not apply anymore.

...I guess that makes me wonder if there is a highly-capable analog-to-digital video adapter out there that can convert the NeXT video signal into something HDMI-safe and in turn be connected to an MDCIM dongle. That would probably solve the problem.

I genuinely wish you luck finding it. Unfortunately I suspect anything capable of massaging such a high resolution and oddball frame rate input into a "standard" video framing is going to cost an arm and three legs. Even finding LCD monitors with VGA ports willing to accept oddball modes has gotten a *lot* harder since the mid-2000s; the oldest, cruddiest, ugliest 17" LCDs in my garage tend to be a *lot* more forgiving about accepting video from things like Sun workstations than more modern ones, which very often just tell you to pound sand if you don't pick a video mode from their list of supported DDC/EDID video modes.

 

[tokenalt]

I genuinely wish you luck finding it. Unfortunately I suspect anything capable of massaging such a high resolution and oddball frame rate input into a "standard" video framing is going to cost an arm and three legs. Even finding LCD monitors with VGA ports willing to accept oddball modes has gotten a *lot* harder since the mid-2000s; the oldest, cruddiest, ugliest 17" LCDs in my garage tend to be a *lot* more forgiving about accepting video from things like Sun workstations than more modern ones, which very often just tell you to pound sand if you don't pick a video mode from their list of supported DDC/EDID video modes.

It's not that hard, I just bought a new monitor that can do it a few weeks ago. A ViewSonic VX2485. Works with my sparcstations, an sgi indy, a mac IIsi, and an amiga 2000. I don't have a nextstation to test it with but I doubt it would have problems with it. Haven't tested above 1280x1024 yet. Real soon now I'll setup my ultra 1 creator3d and see if I can do 1920x1080x72Hz on the monitor.

 

[grog]

First, apropos of the original topic: This may be just a sync-on-green issue. I found this thread on nextcomputers.org and one solution there was an inline DE-15 SOG module. It's possible this would be a less expensive solution than active, signal-modifying alternatives (e.g., OSSC), but after eight years I imagine the trail for this particular doohickey has gone cold. The more forgiving multisync monitors have the SOG circuitry built-in—I get a stable video on the Sony CRT from an Apollo Domain monochrome adapter with just the green BNC connector on a 5 BNC-to-VGA cable. Looks I'm on the hunt for an inline SOG module or its schematic now.

tokenalt sez:
I just bought a new monitor that can do it a few weeks ago. A ViewSonic VX2485.

It is reassuring that some of the monitors still being made with VGA inputs can handle the weirder resolutions and refresh rates. I don't see VGA going away entirely any time soon—while some vendors have tried to introduce HDMI or (mini-)DP for video, VGA is still seems to be the prevailing standard on rack mount servers. However, caveat emptor... not all VGA-capable displays are created equal. I've recently worked with HPE hardware using a something-to-VGA+USB+serial dongle (HP(E) P/N 676277-B21 aka Cisco P/N 37-1016-01 aka ???) and only one of the many display makes/models on our various crash carts could manage to display the video output. The HPE Apollo system in question does graphical overlays and uses various resolutions to unnecessarily beautify the POST and BIOS configuration screens, and given the singular success between the machine, the frankendongle, and the displays, corners are clearly being cut these days to save a few pennies at the cost of full compatibility.

Also, if you also want to go beyond the constraints of de facto 16:9 HDMI formatting and need unscaled DVI 1920 × 1200 resolution or composite/S-/component video inputs (*weakly raises hand*) you probably will have to go back to displays of the aughts (looking at you, Dell 2408WFP). I haven't seen a new 16:10 DVI display in forever.

For those who are okay with cheap, used, non-widescreen options, I recommend the Dell 1707FP as an all-purpose test monitor for Y2K-era or older hardware. Its 5:4 aspect ratio is due to its native 1280 × 1024 resolution (a Sun Microsystems favorite) but in addition to VGA it includes a DVI input that (IIRC) can be letterboxed or stretched. I know from personal experience that this can handle the NeXT color output with only a DB-13W3/DE-15 adapter, as well as sync-on-green BNC-based monochrome or color output.

Raritan color commentary (pun intention optional) follows for those few who want to keep reading...

Eudimorphodon sez:
For laughs I opened up a manual for the old Paragon series, and those seem to have used an analog format for hauling video across the Cat5 wiring, but from digging around more it's fair to say that Raritan has always been more than a little cagy about *exactly* what the heck they're doing; with the newer models I genuinely have no idea if their "digital" CIMs convert video to analog, if their modern analog ones convert to digital, or if the head-end natively accepts both. (Ran across a postively head-spinning CIM compatibility matrix that definitely didn't help, other than make it clear that the Paragon I CIMs haven't been supported for... a while, but there was in fact a weird period where some of them *were* supported by some of the more modern headends until software version x.y.z...) So... yeah. My knowledge of the old ways almost definitely does not apply anymore.

"Alderaan Paragon is peaceful! We have no weapons!"

I've seen that same compatibility matrix in the sacred texts(!) and it makes one go smooth-brained pretty quickly. Not only is Raritan cagy about their interface specs, they won't avail firmware for EOL'd devices after a certain point (I've asked) and there's no trace of copies in the usual Internet software archives. This is annoying in a general sense since there can be marked differences between revisions for any given particular product model (e.g., the MCC switches I have vary in terms of OSD fonts, computer name retention behavior, and tier (in)compatibility)—if you buy ancient Raritan hardware you're stuck with its particular firmware forever.

You can see the advent of the original Cat5/8P8C Paragon pinout emerging from their UKVM, URKVM, and AUATC* devices. One can pair a powered URKVM receiver with the first generation CIMs (before they were called CIMs): UKVMPD (dual PS/2), USKVMSD (Sun), and UUSBPD (USB). I'm guessing around this time the data center rack system market exploded and Raritan decided to drop the old DB-25 CCP(T) cable interface on MCCs in favor of the more densely-packed Paragon. (The 32-port Paragon UMT8 is 1U, while its 32-port predecessor MasterConsole MX432 is 4U.) However, while the adoption of Cat5 made cable management infinitely easier, nothing beats the signal quality of the original CCP(T) cables. (And I'm serious, the Raritan's cable gauge and/or shielding material is like none other—I've tried to use a variety of fully-wired DB-25 extension cables and aside from genuine Raritan CCP(T)xxEs, everything causes ghosting.)

One of these days—probably decades from now if/when I'm retired—I'd like to figure out what each of the DB-25 and 8P8C connector pins actually do. The DB-25 connector almost certainly is just a wire-for-wire aggregation of the VGA and PS/2 (or occasionally Sun) connectors; you'd think there might be some special sauce for switch tiering, but the switch-to-switch connections need only VGA+PS/2 connections on the tier 2 side and it appears to be controlled through elaborate keyboard escape sequences (based on glitches I've witnessed). (Maybe there's some protocol going over the DDC wires? I have my doubts.) On the Cat5 side, three wires are clearly used for unmodified RGB signals (discovered that when one cable with a broken red wire resulted in cyan-o-vision); I'd wager keyboard/mouse signal conversion happens inside the dongle since the three different peripheral dongle types can all speak to the URKVM using the same Cat5 cable.

*I have a soft spot for the AUATC: it's a VT100 in a box with PS/2 (& Sun!) keyboard and VGA hookups... and again, it speaks Raritan U(R)KVM/Paragon Cat5 protocol if you're into that kind of thing. They pair pretty nicely with the consoles of Cyclades/Avocent serial console servers, but that's another thread.

 

[shirsch]

I bring this up often, but an Extron RGB-HDMI 300A (cheap on eBay) can convert anything I've ever thrown at it to HDMI / DVI output. It handles SOG just fine.