Forum: µC & Digital Electronics Need Datasheet/Informations about VFD.

von mcc (Guest)

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I have "rescued" wonderful 2x20 dot matrix character VF display from 
being thrown away.

It was made 10.07.1995 according to the stamp.
It includes  not only the display itsself but a pcb with controller and 
different logic chips on it.

Printing on the PCB:
DISPLAY SYSTEMS M202-MD-07G-2    (the number looks like those used by 

There is quarz oscillator with 11.0592 (MHz/KHz???)

There are for jumper connectors, with printing:
TEST,RxD1,RxD2,RXD3,RxD4. The last one is jumpered, all others are open.

There are two (!) connectores with 16 pins each. Two pins at one of the 
are marked GND and VCC.

There is a little coil or trafo -- may be for generating the higher 
voltage for the
VFD -- soldered on the PCB.

The VFD itsself consists of 2 rows of characters (5x7 dots each). The 
lower row has
also a triangle under each character, pointing down.

On the back of the PCB there a seven chips marked SN75512B made by Texas 
There is also one chip marked SG3524 (Texas Instruments) and one chip 
(C) INTEL 80, 82
9505 .W31214K

It has eleven pins at each of its sides (44 pins in sum).
This one seems to be the "processor" or "controller"...

I have googled a lot but only foudn either data sheets of bare VFDs 
without controller
or descriptions of VFDs with controller, which seems totally different 
to mine.

I would be very lucky if it would be poosible to revive this beauty ! :)

Are t!
mcc here any informations about this display, datasheets, links or 
which could help me to reactivate the display?

Thank you very much in advance for any help!

Best regards and have a nice weekend

von Meino C. (mcc)

Attached files:

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Here are the photos of the VFD...

Best regards

von Sebastian (Guest)

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Well, you know where the power has to go already, I suppose it uses 5 
The "80C51" datasheet will tell you which pins of the controller 
represent the serial port RxD and TxD lines, following the PCB tracks 
from there, look if it uses a level converter like the MAX232 or 
similar. You could try to connect a PC using RS232 (but watch out if 
there is no level converter, then you need TTL levels) and try different 
baud rates in a terminal program.


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