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Handcrafted Scope Clocks with circle graphics

Tag: SVGA

  • Very Good At VGA

    Very Good At VGA

    Recently, [Justin] asked: Can his beautiful Tektronix 606 XY monitor be made to work as a computer display?

    And even more recently, [TJ] explained he has a plethora of Tektronix devices, and asked how he might put them to use…

    So lovely… but what can you DO with it?

    Well, “putting to use” is precisely what we do here at Oscilloclock! And one option, indeed, is to hook the target device up to a modern-day PC and use it as a computer monitor.

    Time for an update on the Oscilloclock VGA Core and its variants!

    Shades of Grey Green

    Avid readers may recall these previous posts about making SVGA and XVGA displays from vintage oscilloscope CRTs:

    VGA display… On a 3″ scope tube!
    The VGA Cube!
    New Year’s Resolution!

    Truly dedicated readers may even recall that the solutions presented drive the CRT directly, completely bypassing any internal circuitry of the host device. And, that there were limitations in the current design; the most serious being binary blanking, where the beam is switched either on or off. There were no shades of grey.

    This Running Man needs no shades!

    Inspired by [Justin], we experimented connecting the Oscilloclock VGA Bare (a barebones VGA interface board) to our lab’s Tektronix 620 XY monitor. This bad boy has an analog Z axis (intensity) input, meaning that we can theoretically have shades of grey… er, green.

    And the result? A pretty decent PC display!

    A recent post, as displayed on the Tektronix 620. (Yes – I know it’s upside down)
    Here’s what it looked like on the laptop’s display

    Doomy Demo

    Ever wanted to play classic Doom on an old green screen? Here we go!

    This Tek 620 is no longer doomed – it’s been Doomed!

    Yes – the display is horizontally inverted. The VGA Bare currently does not support flipping the X and Y signals.

    This unintended challenge makes playing Doom exceptionally difficult!

    Matrix Masterpiece

    Who could resist displaying digital rain (Matrix code) on an old Tek display?

    Matrix code, as generated by tmatrix. Note it’s horizontally inverted

    While working on this demo, I learned more about Matrix code – and that it includes Japanese characters scanned from the creator’s wife’s cookbook. Wow, I thought those raindrops looked awfully familiar!

    The Setup

    Not a bad result! And the hardware setup was simple.

    • PC
    • HDMI to VGA adapter cable
    • Oscilloclock VGA Bare
    • BNC cables and connectors
    • A few resistors
    • Power pack

    As always, nothing is perfect! A few tricks were needed to make the experiment a success:

    1. The VGA Bare circuit needed a few minor improvements, to better support official SVGA and XVGA timing standards
    2. A crude level adjuster (resistive divider network) was needed between the analog intensity output and the Tek’s Z axis input
    3. The PC display resolution needed to be set to SVGA (800 x 600) or XVGA (1024 x 768), to give maximum clarity
    4. A high-contrast theme was selected, to greatly improve display contrast

    What’s next?

    With the successful close of this proof-of-concept, [Justin] and [TJ] now have another clear option to make use of their vintage test equipment: a VGA Bare ready to mount inside their device, or a beautifully encased VGA Connect (à la Oscilloclock Connect).

    But to make this truly production-worthy, a few improvements are needed:

    1. Output voltage level adjustments, fully independent for X, Y, Z
    2. A higher-voltage Z amplifier
    3. Independently invertable X and Y signals
    4. Reduction in the ‘ghosting’ or ‘ringing’ effects currently observed
    5. Improved contrast and avoidance of ‘washout’ seen between pixels
    6. Digital HDMI input !

    … all added to Oscilloclock’s ever-growing backlog of things to do!

    Do you want to play your favourite classic game on your old XY monitor? Do you want to stack 10 oscilloscopes on your shelf and have them all showing Matrix code? Or put your Grandpa’s old scope on your desk at work and have it display your Outlook calendar?

    Our mantra makes it possible: Just. Because. We. Can.

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  • New Year’s Resolution!

    New Year’s Resolution!

    Q: “What’s your New Year’s Resolution?
    A: “Why, 1024 x 768, of course!”

    Geeky jokes aside, here at the Oscilloclock lab we DO have a form of New Year’s resolution! 「日進月歩」Nisshin-geppo, which loosely translates as “Steady progress day by day“, reflects the goal to complete the the once-in-a-decade re-design work, and resume crafting beautiful Oscilloclock products. It also highlights confidence that issues currently facing the wider world will be overcome, one step at a time.

    In keeping with local traditions, [Oscilloboy] wrote the slogan in Japanese calligraphy. But there, tradition ended and true joy began! Behold, courtesy of an Oscilloclock VGA Core assembly, Oscilloclock’s 2021 New Year’s resolution on a beautiful old 7-inch oscilloscope!

    The Setup

    After choosing an appropriately meaningful four-character phrase for our resolution, I asked [Oscilloboy] to write out the characters. Bucking with tradition, we used standard white A4 paper instead of calligraphy paper. The ink took more time to dry, but we wanted to maximize the contrast.

    [Oscilloboy] demonstrates his prowess in Japanese calligraphy. Right: the finished product!

    After scanning the handwritten characters and inverting the images, I created a rolling video in 1024 x 768 resolution. (See? The joke at the beginning of the post about resolution was serious, after all!)

    I then played this through an Oscilloclock VGA Core assembly, which is essentially a graphics card that allows you to use a beautiful old CRT as a rudimentary computer display. (For earlier write-ups, see VGA display… On a 3″ scope tube! and The VGA Cube! .

    The assembly used here features a late prototype of the Revision 3 Power Board, which I have been working on for almost a year. I won’t go into all the bells & whistles yet. Stay tuned!

    A VGA Core assembly – displays monochrome images from VGA, SVGA and XGA inputs

    Unlike a permanent Oscilloclock conversion (see the Gallery for examples), this was only a temporary setup. The VGA Core was positioned externally, with the harness routed into the 7VP1(F) CRT via the rear of one of the side panels. No invasive procedures needed!

    Just LOOK at that beautiful CRT socket – brown Bakelite!

    No VGA socket on your ultramodern slim notebook of choice? No problem – use an off-the-shelf HDMI to VGA converter!

    And voila – the final result! Japanese calligraphy on a vintage 7″ oscilloscope!

    About the Model – A rare 1963 Nitsuki Oscilloscope

    Nitsuki is the brand name of Japan Communication Equipment Co., Ltd., a specialist in television and microwave broadcasting systems. The firm’s English name was originally Nihon Tsushinki Co., Ltd., so you can see how the Nitsuki moniker came about.

    Check out this exquisite cap on the pilot lamp!

    By 1963, the Japan domestic test equipment market was mature and quite competitive. English language labeling had become stock-standard. This scope is one of very few units I have ever obtained that has Japanese labeling. How appropriate for today’s display!

    Japanese labeling – a rarity!

    Some of the higher-quality oscilloscopes of this era featured flip-latches and detachable side panels, for easy access. See the Toshiba ST-1248D for another example. These scopes are infinitely more enjoyable to work with and show off than scopes with a slide-out chassis.

    This model is also quite unusual for its time in that most of the components are located under the chassis! The valves (tubes, if you prefer) are even mounted horizontally. Nitsuki used very robust construction techniques, including very tidy cable lacing.

    In fact, their design was so robust that the scope functions almost perfectly today (except for some triggering instability), yet there is no evidence of major repairs in the last 57 years!

    Back to its natural self – a nice old 7-inch 1963 oscilloscope!

    Like what you see?

    The Oscilloclock lab struggled in 2020 due to worldly events, but NOW – day by day, step by step, the newly designed Oscilloclock boards are at last taking shape! Does your New Year’s ‘resolution’ for your next project specify 1024 x 768? Or perhaps you’re into displaying fancy calligraphy on vintage CRTs? Let me know.

    And as always, see previous posts and the Gallery for info on other unique creations!

    Critical Update 25 December 2021

    Well. Christmas Day 2021, and [Oscillowife] — the chief editor, advisor and critic extraordinaire — just informed me that I had placed [Oscilloboy]’s first character「日」upside down when creating this post! Apologies to our readers for the gross oversight.

    It’s been 12 months! But better late than never to eat humble pie…
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  • The VGA Cube!

    The VGA Cube!

    It’s been a long while since I wrote about the 3″ VGA Display assembly, which was used for an RWR indicator in a fighter cockpit simulator.

    The customer came back and requested four more. But could I stack the boards to make the units more compact? Of course!!

    This particular assembly is rather tall because the client requested an in-built mains supply board, sitting at the bottom. The normal configuration using an external power pack is half the height. (In which case it’s not quite a “cube”…)

    With green filter and replica RWR escutcheon fabricated by the customer. How real is that!!

    And if you aren’t into aircraft indicators, you could always have a bit of fun!

    Is a VGA Cube right for you?

    Maybe. Or maybe not! These units incorporate binary blanking – I.e. The beam is either on or off; no shades of grey. Hence any VGA image composed of thick line art like RWR will display well, but shaded or coloured displays such as an attitude / horizon indicator would not work so well.

    Below is a Windows XP login screen… Not exactly a flattering image!!

    VGA Board – better and better

    The latest VGA Board rev 1.1x is small and cute, and is compatible with the standard Oscilloclock Deflection and Power Boards.

    In keeping with tradition, the VGA Board employs entirely analogue techniques to generate the horizontal and vertical sweep, triggered by incoming sync pulses. A high-speed analogue comparator with adjustable levelling is used to convert analogue RGB into binary blanking. Naturally, inputs are ESD protected so you can’t easily blow the chips!

    New VGA Board revision (left) – meaner and leaner!

    Like what you see?

    VGA Cubes are like any other Oscilloclock product – each unit is hand-crafted to order and fully tested so that I can optimise for the selected CRT and provide a decent satisfaction guarantee. To date I’ve made five – and always happy to discuss a sixth! If you have a passion for raster rendering, let me know!

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  • Heads Up!!

    Heads Up!!

    Recently I received a most intriguing request: I was asked to build a self-contained, super-bright X-Y display unit with 3-inch CRT, for use in an “HUD“. Hmm…

    Holographic Utterance Device?
    Horizontally Unstable Doohickie?
    …

    Fortunately, I didn’t need to guess any further. As I was once an avid flight simulator enthusiast, I quickly hit upon the correct meaning: Head-Up Display. This is a mechanism that overlays instrumentation or map data onto the view looking forward from the cockpit, so that the pilot doesn’t have to look down to see this information.

    HUD in an F-18 aircraft. Source: AC Aviation Life
    HUD in an F-18 aircraft. Source: AC Aviation Life

    Wikipedia has a great introduction to HUDs and their history, but Mike’s Flight Deck has the definitive tome for flight simulator enthusiasts who want to actually build an HUD. According to Mike, the system employs various optical paraphernalia, but at the heart of the mechanism is what lies closest to my own heart – a CRT Display!

    Oscilloclock 3-inch X-Y-Z display, custom-built for an HUD
    An Oscilloclock 3-inch X-Y-Z display unit, optimized for use in an HUD
    (more…)
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