Do you, by chance, have any information on the handheld controller interface for these? I'd like to build my own remote -- maybe even something that runs serially with the handheld -- but I'm not sure how the pins are used. My assumption is that the 4-pin RJ-11 has a ground, status LED wire, and then the two remaining are connected to the rocker switch (start/stop the clock) and the buzzer momentary switch.

What I don't know is if there's any kind of impedance/debouncing circuitry incorporated into the handheld or if that's all taken care of on the controller side so the handheld can be super cheap/easy. My assumption is the latter, but I don't want to wire something up and potentially fry the controller.

Has anyone taken one of these apart to know for sure?

My concern is I don't own the unit I'd like to augment, so I don't want to risk opening it up and/or damaging it. I'd like to just create a project box that has an RJ11 in/out that I can put in line with the controller that I can use to read whether the buzzer is being pressed or if the clock is running.

Thanks for any help anyone can provide!

You'd have to backwards engineer the entire protocol on the handheld switches and keypads, not an easy task. They all run off the same serial bus and each have a unique ID.

It's not really a nonstandard protocol, more like it's... not a protocol. Historically, CPUs were expensive, right? So scoreboards were pretty dumb devices. The displays were cheap shift registers feeding cheap latches, which directly drove cheap triacs that lit incandescent bulbs. One timer triggered on the rising edge, and its expiration told the shift register when to read the signal line. The latch trigger came from either a second timer that knew the packet length, or a pulse counter. Pick apart the driver board from any scoreboard made between about 1978 and 1995, whether it's Nevco, Fair-Play, Daktronics, or anyone else, and you'll find very similar circuitry. (Nevco may have gotten cute using BCD-to-seven segment decoders instead of a plain 8-bit latch.)

The controllers in the latter half of that period usually had a CPU. Fair-Play used the same 6510 as the Commodore 64. Older controllers (Nevco and Fair-Play among them) had the inverse of the display board--thumbwheel or rotary switches were multiplexed into the right stream of bits.

In the 90s, Daktronics started building display driver boards with microcontrollers, and about 1995, switched from unframed 12800bps serial to the 19200-baud properly-framed async serial you've already decoded. Fair-Play made the switch a few years later. Nevco has held out for a long time, but I think they also changed with their MPC-6 controller--it will drive older boards, but MPC-5's won't drive newer boards. (I have an MPC-6, but I haven't hung a scope off it yet.)

If you go back before the late 70s, you get scoreboards that are *totally* undecodable. The controllers had huge multi-pin plugs, because they were just pushbuttons with long leads. Inside the boards, the digits were driven by ganged rotary switches which were advanced by solenoids. Push the "Home Score 1" button and you hear a loud "kerchunk". The 10s digits were controlled separately and manually. My high school had an old Fair-Play board mounted on a cart that used a rotary dial from an old phone to quickly input the player and foul digits. The clocks had the only complicated circuitry, to decrement 10s and minutes.

Hello Xiao and Jason. I have an American Scoreboard MP-3310R baseball scoreboard with wireless console. It works. What I am trying to do is control this from my home automation system ( I am a dealer and programmer of Crestron Automation systems) My end goal is to parse play by play stream for Red Sox games and update the scoreboard in my office. I have the programming side done, but need help with the hardware. My Crestron processor can talk RS-485, 422, 232. But I am not an electrical engineer and do not know how to tap into some serial communication on this thing. I would love your guidance on this and can compensate you for your time. c a s e y AT h r a v DOT net

do you think this is completely different from the MPCW-7? Hardware basically BNC 50 ohm -> logic Level Converter -> Teensy -> laptop python?

I would think it is the same protocol, since it supports the same scoreboards.

Was a senior EE at Nevco for 10 years from early 2000s to mid 2010s. While there I helped redesign the entire outdoor and indoor scoreboard lineups as well as many other projects while there. That damn coax protocol, it doesn't match anything cause we (nevco) made it up from scratch. It was developed many many decades ago by a nasa engineer that Jan Nevinger hired back in the day and we had to maintain use of that protocol, even on new boards. They always wanted that backwards compatibility! You can plug a modern controller into an old wood cabinet scoreboard and operate it if you can believe it.... There are some places you can use entire bytes, other places you're playing with nibbles, and if I remember correctly, the signal itself is patented somehow. I think reading it was ok but generating it was not? I honestly can't remember... Anyway, was looking for something else nevco related and happened upon this post so wanted to say hi and good luck!