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Thread: Dubner 20k, mysterious artefact from local TV station's dumpster

  1. Default Dubner 20k, mysterious artefact from local TV station's dumpster

    A few months ago, a TV news station in my town was doing some spring cleaning and right before a big rainstorm blew in I managed to save a bulky, heavy hunk of machine I knew looked interesting but still have very little idea of what it is or how it could be utilised by a old-computery-junk fan such as myself. Based on the fact I pulled it from a dumpster, a viable conclusion would be that it stopped working and that repair was impractical, although businesses do often rid old equipment from inventory after new stuff has replaced it, and with the switch to digital High Definition broadcast, one could suspect a portion of equipment to be obsolete solely for its incompatibility with the new HD format. Regardless, the components within this rack-mountable metal heap look like they might be replaceable by re-soldering, or I could toss it out and it's no big deal.

    The reason I am asking about it here isn't that I believe the machine itself is a vintage computer, despite that it is referred to online as a "character generator" and has enough in's and out's to suspect it has enough brains to display graphics somehow. Instead, I ask because it has a 8-inch optical floppy disk cartridge drive and would appear to interface (to something) via a SCSI ribbon cable. What I wonder is whether read/write to the 10MB, 8-inch cartridge is possible, and if the contents of a disk labeled "NEWS '97" may be read (unless they have corrupted). Because there is no keyboard or evidence of human interface input besides a series of fine-adjustment knobs labeled with technical TV jargon (excluding the DE-9 ports for who-knows-what) I'd bet it had to have been hooked up through SCSI to some type of PC, unless by chance the PC had its own disk cartridge drive or something like that, which I believe to be less likely.

    I had attempted to plug it up to the SCSI controller in my computer, turning the Dubner's switch on and then powering up the computer, but neither Linux 2.6.? and Windows XP wanted to boot; Linux got in a loop with detecting SCSI devices and declaring a device was present and starting over again, while XP held at the boot logo until I gave up. If I were to find drivers, I have plenty of SCSI-capable platforms at my disposal, including a 486, an Amiga, and Macs, so most of my bases are covered.

    I've included pictures, hoping some handy engineer-type might readily know any more information about this device or that I might be pointed in the direction of a resource someone might know of, because the most I can find online are short descriptions on these systems being sold on ebay and elsewhere for large amounts of money with no evidence of anyone buying them. I've asked around the TV station and no one seems to know anything about it. I'm interested in these things regardless of the working state of this contraption. The world of analogue video, odetics machines, rolling tapes, and miscellaneous specialised machines like this one is becoming lost to history as advancements to generic x86 PCs and networking take over. I believe this thread qualifies as vintage computer-related, but I apologise if others disagree. I won't take it personal if this thread instantly dies.

    (BNC jumpers were connecting various things, but I removed them after taking good note of which was plugged where)
    Last edited by reverendsean; July 14th, 2012 at 04:43 PM. Reason: didn't attach pictures correctly the first time

  2. #2


    I wasn't able to view the attachments. Look anything like this?


    According to eBay, it's a Dubner 20K Optical Storage Floppy Drive DPSI 5.25"
    Attached Images Attached Images

  3. #3
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    The disk is for a 10MB Bernoulli Drive which I presume is the drive installed. See for a matching image.

    Without a closer inspection I can't be sure but I suspect that the Dubner system is a complete specialized computer that placed text over video images. Your local station's weatherman probably used it and might be a good source for more information.

  4. #4


    Also read here that it's a character generator/broadcast titling device.

    Maybe it loaded character generating programs from floppies to display during a newscast? I don't know what else it can do, that's what a Google search turned up.

  5. #5


    Quote Originally Posted by krebizfan View Post
    The disk is for a 10MB Bernoulli Drive which I presume is the drive installed. See for a matching image.

    Without a closer inspection I can't be sure but I suspect that the Dubner system is a complete specialized computer that placed text over video images. Your local station's weatherman probably used it and might be a good source for more information.
    Wow, nice guess. Beat me to it...

    Quote Originally Posted by reverendsean View Post
    I believe this thread qualifies as vintage computer-related, but I apologise if others disagree. I won't take it personal if this thread instantly dies.
    Don't worry, your thread definitely qualifies as vintage.
    Last edited by WMH; July 16th, 2012 at 11:43 AM.

  6. Default

    Thanks! I was especially interested in the disk drive, and knowing what it's called definitely helps out.

  7. #7
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    Quote Originally Posted by krebizfan View Post
    I suspect that the Dubner system is a complete specialized computer that placed text over video images.
    Yep, I worked in TV current affairs for some years in the analog days and that looks like a subtitling system. I don't know that brand, but look at the logo - it's a continuous loop. I'd guess this thing loaded a page of graphics into RAM and sent that out as a signal that would normally be mixed at the desk. The configuration of the rear ports also suggest it might have the capability for internal video signal mixing.

    This would have to be manually controllable.

    Probably had continuous scroll mode, page cue mode, and line update mode at least.

    Normally, you would expect such a system to have live keyboard input for real-time updates, and perhaps also lines in from external text sources such as wire services - using those D9 serial connectors?. I can see what looks like a RAM array for video page and possibly a bunch of character generator ROMs. There must be a CPU somewhere and maybe a boot ROM? Its unlikely that updates would be limited to pushing carts or disks in or out, though that might be one of the update modes. Cartridges would hold large graphics, logos etc to be called into a page as needed.

    You could always try patching output from those top-row BNC sockets to the antenna input on an old TV. There are trimpots for sync and phase and maybe color? They seem to be plain NTSC video outputs.

    Not sure about the 50-pin IDC connector near the power input - can't read the label. Maybe link to a control module?

    I'd guess there's a good chance this is fully functional and was only dumped when the station switched to digital production chain.


  8. #8


    I worked as a broadcast television engineer for 12 years and help maintain a Dubner 20k for much of that time.

    It's a dedicated character generator. A glorified video word processor. You would create each screen of graphics, save it to a file, put the files into order in a playlist. In live news, when the director called for it, you would advance to the next page. You could also use it to make the text for promos, commercials and anyplace else you needed text on video.

    This box lived in a rack of equipment outside the control room wired into the station's infrastructure. It would have a cursor monitor connected where you could actually see what you were typing and a program out monitor that showed the graphics without the cursor.

    A specialized keyboard was placed in front of those monitors connected via serial port and had a local wall wart too.

    The OS was copied onto each 10MB Bernoulli disk. You booted off of the disk and used the remaining space for pages of text, fonts, and custom graphics. It was tradition that each new CG operator created their own disk to use and set it up the way they wanted.

    We upgraded to 90MB Bernoulli disks and then I got the bright idea to try Zip Disks. They worked great except the system saw only 90MB per disk thinking them still Bernoulli.

    It was a totally standalone system. No PC required, although custom graphic elements could be imported from regular computers. It did not have the horsepower to do weather maps or anything terribly complicated. Just the lower 3rd you still see on TV with name and occupation or other simple text.

    It probably still internally works. Built like a tank. The Bernoulli drive failing was common.

    It was strictly standard definition. No high definition capability at all. If you turn it on and connected a BNC to RCA cable to a composite input of a TV you would see a BIOS init if it was working.

    Any other questions?

  9. #9


    Quote Originally Posted by RickNel View Post
    Not sure about the 50-pin IDC connector near the power input - can't read the label. Maybe link to a control module?
    It's a 50pin SCSI connection for auxiliary drives. I put a secondary external SCSI Zip Drive on that port to make copying easier. That was a fun adapter cable to make.

  10. #10


    I suppose my response to your post would've been more interesting had I noticed the original a year and a half ago. But my mother just now brought it to my attention. She was alerted to it by my niece, who found it Lord knows how. I suppose that it's evidence that Melanie spends a lot of time wandering the Internet.

    The gadget that you found in that Dumpster is a Dubner 20K.

    It got its name because somewhere around 1983, Harvey Dubner, the president and founder of Dubner Computer Systems, spoke with his son Robert, who was effectively becoming Dubner's chief design engineer. One has to be careful saying that, since there were a number of top-notch hardware designers creating products at Dubner at that time. Joe Schwartz, Andy Cooper, Charles Kerman, Mick Ghazey, and Gene Spiller, among others, were all designing stuff. But I -- oh, forgive me, I should have introduced myself. I'm Bob Dubner -- was pretty much taking the lead on the character/graphics generators.

    We were selling at that time the $150,000 CBG, which had been designed during the latter part of the 1970s. It was, in part, a direct response to the Chiron (later Chyron) character generator -- ABC Television, tired of what they felt was Chiron's exorbitant pricing and lack of response to ABC's unique needs, wanted something they controlled, and paid us to develop a more powerful system. We later repaid ABC's development funding so that we could market it generally.

    Around that time Chyron started marketing less expensive CGs, and Harvey wanted to compete in that space. So he came to me and said "Design a character generator we can sell for ten thousand dollars." I said, "Great! What are the other requirements?" "I want to sell it for ten thousand dollars."

    Oh. Okay. So me and the other guys started knocking our heads together -- not "putting our heads together", Dubner didn't work like that -- and with the software guys wanting the moon and the stars, and me wincing at what they wanted and dragging my feet because I knew damned well that if we were going to sell it for ten grand that I'd have to keep the hardware costs down to around three thousand dollars, and that wasn't going to be easy -- or possible, for that matter.

    And as I started designing and later prototyping, we needed a project code assigned to it for tracking our time. And the project needed a name. And because the only design specification I had was "...ten thousand dollars..." I gave the project the name "10K".

    Which stuck.

    The original 10K ended up selling for about fifteen thousand dollars. The disk drive that it used was a 5.25-inch floppy. If memory serves, the CPU was a Motorola 68000. The operating system and file system were homegrown; there wasn't a single line of code in the box that we didn't write ourselves. I know that kind of thing makes people gasp in horror now, and to some extent back then. But when there was a bug, we could find it. If something needed to be optimized, we could optimize it. And our primary customers were broadcasters and post-production houses, and at that time they regarded time as money. The multi-minute boot times that we all routinely put up with now would have gotten a vendor laughed out of the building in 1984. Our products were always ready to run within seconds of being powered up.

    There are, of course, disadvantages to home-grown stuff. In particular, I still wince when I think about those 5.25-inch floppies. Gene Spiller figured out that we could format the diskettes ourselves with a couple more sectors per track and get almost five percent more storage than the standard formats. So we did that. Which meant that you couldn't put those diskettes into any of those newfangled IBM PC computers starting to float around. In retrospect, we shouldn't have gone down that route.

    Your salvaged box is the 20K. Pretty much the same single-plane with alpha channel NTSC/PAL video generator, but with an interface to an Iomega Bernoulli 10 megabyte stabilized floppy drive. Again, the file system was completely our own, so there's pretty much no hope of reading anything off of it except as raw sector data.

    We were so damned excited about the Iomega drive, which got 10 meg (later 20 meg) onto an eight-inch floppy by flying it over a flat metal plate and sticking the read/write head through a slot in the plate, letting them get the head/disk distance down to a few microns. We may have kept Iomega afloat during their early dark days; I can't tell you how many people I sang Iomega's praises to after Iomega gave them my name as a reference. An Iomega sales rep told me about a year later that we had bought about two-thirds of all the cartridges they'd sold up to that time. We didn't care what went wrong; we needed them to succeed. The interface to the Iomega drive was a 50-pin flat ribbon cable; maybe that's what you saw in there.

    The 10K/20K had its own dedicated keyboard with a serial interface. The unit was completely standalone, although it could be remotely controlled through the serial interfaces. Networking was a stunt back in 1983; we never thought of using it for control, nor did anyone else at that time. Serial interface -- RS-232 for short haul, and RS485 current loop for long haul -- was the order of the day.

    It wasn't just a character generator. The display plane worked on run-length encoded segments, each segment being a length and an index into a color lookup table. This gave tremendous flexibility for both characters and graphic images while using memory in an economical way. The bad news for experimenting thirty years later is that without knowing how those images were stored, it'd be a bit of a project in cryptanalysis teasing out the LUT and the overall run-length structure in order to have the satisfaction of seeing, "More at eleven!" appear on your computer screen.

    The 10K/20K evolution continued into the two-plane 30K, which had more memory and a 68020 processor. That led to the 40K, with its 68040 processor and an auxiliary RISC processor on its own board for really speeding things up. At "40K" the software and marketing folks rebelled, and that machine became The Graphics Factory.

    Dubner Computer became a wholly-owned subsidiary of The Grass Valley Group in 1984. GVG reorganized in 1991, and Dubner Computer ceased to exist as a separate entity at that time. My father and I left the company around then. Since then that group has been shaken up, shrunk, reorganized, and sold numerous times. I believe that if you look real hard, you can still find a couple of people working at Avid who trace their ancestry clear back to Dubner Computer -- they've neither been hired nor fired along the way; they just keep getting new business cards every now and then.

    Those were good times. And Dubner was, simply, the best possible place to work. Thanks for reminding me.

    Does that answer your question?

    Bob Dubner

    p.s. I am now sixty years old, working in the financial sector as a quantitative analyst. Most of my work involves implementing financial and investment models that the math boffins in my group cook up. My father is a hale and hearty eighty-five years old, fully retired in New Jersey.
    Last edited by rdubner; November 23rd, 2013 at 12:22 PM.

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