Old LED electronic display

[Jerry Abrams]

Our school has an old unlabelled LED display, LED's are all red, has a
black aluminum frame with a attache case handle on the top. The size
is about 40 inches long by 12 inches high. There is a 3 conductor 1/4
jack that connects to a DB 25 plug (female so it probably connects to
a serial port of an MS-DOS machine). Turning it on (it just has an AC
plug, no switches) prints 4 scrolling lines of garbage. Openning it
up, there is no manufacturer listed on the circuit board in the center
of the unit. Anyone have any ideas who made this, would it
communicate with the Hayes "AT" modem command set?, or did this units
have proprietary software? Could anyone identify the unit based upon
the description (probably from the late 1980's). Thak you.

 

[Colin Dawson]

"Jerry Abrams" <jabrams4@optonline.net> wrote in message
news:c37dd2c9.0403261152.1791e767@posting.google.com...

Our school has an old unlabelled LED display, LED's are all red, has a
black aluminum frame with a attache case handle on the top. The size
is about 40 inches long by 12 inches high. There is a 3 conductor 1/4
jack that connects to a DB 25 plug (female so it probably connects to
a serial port of an MS-DOS machine). Turning it on (it just has an AC
plug, no switches) prints 4 scrolling lines of garbage. Openning it
up, there is no manufacturer listed on the circuit board in the center
of the unit. Anyone have any ideas who made this, would it
communicate with the Hayes "AT" modem command set?, or did this units
have proprietary software? Could anyone identify the unit based upon
the description (probably from the late 1980's). Thak you.

Any chance that you can place some pictures of the circuit board on the web?
Make sure that it's in focus and it's possible to read the model numbers on
any IC's, if that's not possible a more general shot of the whole board, and
some text telling us about the models numbers.. If there's anything at all
writting on the board - manufacturer (I know not in this case, it's a useful
aid to anyone else who is tring to identify a board), model number serial
number or anything else that could jog someones memory. The more
information that's available the higher the chance of being able to identify
the board ;-)

Regards

Colin.

 

[Spehro Pefhany]

On 26 Mar 2004 11:52:42 -0800, the renowned jabrams4@optonline.net
(Jerry Abrams) wrote:

Our school has an old unlabelled LED display, LED's are all red, has a
black aluminum frame with a attache case handle on the top. The size
is about 40 inches long by 12 inches high. There is a 3 conductor 1/4
jack that connects to a DB 25 plug (female so it probably connects to
a serial port of an MS-DOS machine). Turning it on (it just has an AC
plug, no switches) prints 4 scrolling lines of garbage. Openning it
up, there is no manufacturer listed on the circuit board in the center
of the unit. Anyone have any ideas who made this, would it
communicate with the Hayes "AT" modem command set?, or did this units
have proprietary software? Could anyone identify the unit based upon
the description (probably from the late 1980's). Thak you.

There were a lot of different manufacturers of this sort of thing. I
have a couple of different and incompatible units. I don't know if you
have much hope of figuring out the command set short of disassembling
the firmware (typically they used an 8051 with external EPROM). This
would be rather a time-consuming task. Much cheaper to buy a new one.

It's possible/likely that if you just send it ASCII using the correct
protocol (try the ubiquitous 9600 n 8 1 first) it will display the
text like a TTY. That may be good enough for you to put it to some
use.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[dont know]

Jerry Abrams wrote:

Our school has an old unlabelled LED display, LED's are all red, has a
black aluminum frame with a attache case handle on the top. The size
is about 40 inches long by 12 inches high. There is a 3 conductor 1/4
jack that connects to a DB 25 plug (female so it probably connects to
a serial port of an MS-DOS machine). Turning it on (it just has an AC
plug, no switches) prints 4 scrolling lines of garbage. Openning it
up, there is no manufacturer listed on the circuit board in the center
of the unit. Anyone have any ideas who made this, would it
communicate with the Hayes "AT" modem command set?, or did this units
have proprietary software? Could anyone identify the unit based upon
the description (probably from the late 1980's). Thak you.

around that time (1980) it was popular to make these signdisplays
that you now find in subways, storefronts etc.
It all depends what micro is in there, but the had to be programmed
from a port (cp/m computer, 300-2400 baud). You will probly find shift
reg,
small amount of memory, etc in there