Checkmate 19" 4:3 Retro IPS Monitor

xrayspx's picture
xrayspx - Sat, 03/21/2026 - 11:22pm
Music: 

The Disposable Heroes of Hiphoprisy - Television, The Drug of the Nation

For a year now I've had a Checkmate 19" 4:3 aspect ratio monitor, and I want to show how that's getting used. The reason I kind of sat on it for so long is that I got frustrated, then depressed and spiraling, and finally decided to fix things and spend myself out of my problems. For Health! And here we are, fully working solution, I'm super happy.

I've seen these monitors start showing up in videos from folks like Nostalgia Nerd and Modern Vintage Gamer, but I haven't seen them really exploring it so I want to share some of my favorite use cases. And with my upcoming sabbatical I'm planning on doing a lot of projects involving the machines you'll see here so I wanted to kind of intro everything before I get started on those.

So let's go check it out!
(Caveats: I am not comfortable making videos, and I'm not good at it. I didn't edit out many of my "behind the scenes" bumbling because if I have to figure it out, you have to watch me figure it out! Hopefully you find my awkward bumbling "charming")


TL;DW;

The Checkmate is not just a monitor, it's also an integrated electronics project box, 2u mini-rack and hacking platform.

Basically as I said I ran into one or two semi-issues. The 15Khz horizontal scan rate thing on the VGA port was a real bummer and sent me down a hole, but the OSSC Pro worked out great to help solve that, even though I really don't understand that thing at all. It looked like shit for like a month and just through random button-mashing I got it to work great for both mono and color on the ST. Thanks to CTRL-ALT-Rees for the in-depth review of the OSSC vs RetroTink video specific to the Atari ST platform. If I ever get up the courage to do a factory reset on the OSSC I'll try and document exactly what settings need to be twiddled to make this work in my case.

Thanks again also to BackOfficeShow for leading me to the realization that converting ST to VGA was all just a simple passive "hook the wires to the other wires" process which inspired me to do my Monitor Master hack!

Future projects and other use cases

  • I do want to see if I can hack a GoTek in there to use as a drive on my ST with the rotary encoder in the monitor. That would be about the slickest thing imaginable. I'll probably get a GoTek with an encoder and try to remove that one and use the monitor one instead.
  • There are 12VDC headers on the backplane board. Can I wangle one to a barrel jack and mount an 8 port switch in here? I have a couple of 12v@1A Netgear GS108T switches and I'd love to see if I can pull that much power and have a little self-contained network. This is pointless. The Pi in there is just on WiFi, but I kinda want to see.
  • My most recent job ships cases and cases of hardware to healthcare trade shows. Much of the network hardware for the booth and even small PCs for running demos could easily be securely fitted into a Checkmate with the HDMI out going off to a big TV.
  • Portable industrial control and automation platform as a self contained control station again with several SBCs and integrated network switching
  • I'm a network and datacenter-ops guy who naturally looks at everything through that lens. If I were building a crash cart or repair workbench I'd love these just to fill with low power SBCs (Pi 3 works great) and switching for a portable KVM, isolation network and test suite.

    While they're not "cheap" for a consumer product, thinking in terms of even small-scale datacenter hardware they're an absolute /steal/.

    Other Quirks

    I did run into a race issue with the Raspberry Pi as well. I think it takes a bit for the monitor to be fully up and ready to receive video as it starts up. At first I thought it might have been an inrush current type thing, but I think it's just that the monitor isn't "up" yet when the Pi starts shooting out video.

    When I'd boot the monitor cold there would be no video until I unplugged and re-plugged power to the Pi. To fix that I added a 10000ms delay to /boot/config.txt and it works great:

    boot_delay_ms=10000

    To give you a sense of the depth of my personal psychosis, the other issue I kind of have is a ridiculous future-proofing one that is bonkers to even be worried about. There are 6 HDMI inputs on this monitor, but only the main one is directly addressable through the front-panel buttons. Using the front panel, you can switch between HDMI-1 and one of HDMI-2 through HDMI-6. To select between HDMI-2 -> 6 you must use the remote. You can kind of see me do this in the video.

    From what I can figure out this of course makes total sense. The UI firmware of the panel, like the off-the-shelf stuff that is the same as the EYOYO monitors, knows nothing about the riser card with all those extra ports on it right? The firmware knows about two ports. The external HDMI-1, and an Internal HDMI that the mezzanine card plugs into, and can select between them. The remote therefore isn't interacting with that COTS firmware to do this, but instead it's controlling the mezzanine card to switch the input among the other 5 ports, which is a very neat way to work around that. I mean obviously the firmware can select the riser card ports, because that's where the composite inputs live as well. If I had to guess it "only" had code to handle two HDMI inputs, so this workaround was implemented.

    That's obviously a totally rational way to do this, and really the only way you probably can. It's awesome. My "planner" brain is just saying well, what about in 30 years when that remote is dead or lost. How do I select those ports?

    For all I know I can control that mezzanine card totally in code over GPIO from a Raspberry Pi, or serial, or LIRC (which this probably is). Who knows. That's Future Guy's problem. I haven't even dug into that, but I certainly intend to! I want to see just how far I can push this.

    Greetz and Links

    Checkmate1500plus.com for making an excellent project out of total engineering passion. Excellent work all around to Steve and Appy and the rest of the team!

    BackOfficeShow.com for showing how easy it can be to convert ST to VGA and switch between mono and color.

    CTRL-ALT-Rees.com for his in-depth OSSC testing and demonstration.

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