Text Lite MM500 LED Display från 1982

Hittade denna ovanliga display på en loppis. Tyvärr saknade den tangentbord men för endast 35kr var det totalt omöjligt att låta bli att köpa den!

Framsida MM500

Baksida MM500

Utan skal MM500

Den fungerar, det syns svagt lysande figurer till höger på den nedersta bilden. För tillfället går det inte att mata in ny text, men den har en seriell anslutning så nu är det stora projektet att fundera ut hur man ska koppla in den till datorn utan att släppa ut den magiska röken.

MM500 interface

MM500 processor

13 replies
  1. jobe
    jobe says:

    Hi, I am also working on this display.
    Contact me via e-mail if you want
    to collaborate on this, please.

    (Jag kan också läsa lite svenska)

    • nikmitko
      nikmitko says:

      Hello! I have such a display but I have lost the instruction to enter text from the keyboard. Would you follow my instructions? thanks

  2. ledow
    ledow says:

    I have a working one of these, still in the box with the manual and keyboard.

    The keyboard seems to be just a basic matrix keyboard on a ribbon cable (although it appears to fit in “upside down” to me). When connected it “beeps” for every detected keypress so that might help you find the right connections. I may or may not be able to open it up and have a look at the exact matrix but it doesn’t appear to have any electronics in it. If your memory (text module) is dead, it displays % symbols, but it still works – it just needs a reset command typed on the keyboard first (shift key following by K key, I think. Shift key is a simple toggle, not a hold-down type). Obviously, power loss results in a zeroed memory again.

    The serial port is barely mentioned in the manual (RS232C – but doesn’t mention voltage levels -, stereo 3.5mm socket, one input, one output, one ground.) but I found an old computer made by the same company at the same time that suggests it can be programmed serially quite simply:


    Search for “moving message displays” in the PDF.

    The only other features are sync cables (simple mono 2.5mm headphone cable between two units – unknown protocol). If anyone needs more information, give me a shout.

  3. Frost
    Frost says:

    Thanx for the information.

    Jobe above also suggested that it was probably a matrix keyboard. I’ve tried all possible combinations of the pins. Never a single reaction of any kind. And absolutely no beep. The memory module seems fine, the CPU too, it displays running text, but i cant reprogram it. There is not much information about the MM500 on the internet, so all the information you want to share is greatly appreciated.

    I think I’ll take out the LED sign and try a few different approach on the serial communication when I read the attached link.
    Thank you again!

  4. DennisS
    DennisS says:

    The other text-lite manuals give more information.
    In the MM-505 manual I found some specs for the serial port:
    1200 baud
    7 databits
    even parity
    2 stopbits

    When i connect to the mm500 with these settings the scrolling text blinks shortly when i press the keys (connected via Hyperterminal)

    When I press CTRL B the mm500 gets in some kind of modus where you should be able to write text, ending with CTRL C.
    This gives scrolling scrambled text, not nearly what I have typed.

    Sometimes in the CTRL B modus the mm500 gives some error messages like “L1 pressed too long, see chapter 5.0 in manual”

    It would be nice if we’ll get the mm500 to work with the kitchi software to show RSS feeds on it.

  5. sniffels
    sniffels says:

    Hi All, I have a MM700 and i would like to controll it with an arduino.

    Does anyone have a libary or an idea how to controll the module.

  6. eptheca
    eptheca says:

    I just got hold of a MM700 display. It’s not working. A short circuit blew a Tantalum Capacitor, and probably some of the components around. I replaced them, but it’s still not working.
    If anybody have a service manual, or have connected to the LED-modules with an Arduino, I am very interessted.


  7. TextliteNL
    TextliteNL says:

    And in 2019 there’s still someone looking for how to operate a MM500. This seems to be the only site with information. Does anyone have a clear how to on how to operate the MM500 with Putty?

    I tried:
    1200 Baudrate
    7 databits
    2 stopbits
    even parity
    flow control none (?)

    I already found out ctrl+k means enter/return, but there is not a single hint my tries are working. As the links are getting older I’d really love to get this working!

Trackbacks & Pingbacks

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply