Before anyone gets worried, this is nothing nefarious or illegal. I have a parallel line connected to a printer. I only have access to the printer end of the line and not the source. What I want to do is write an application to intercept this data and use it to drive
programmable LED message boards. I want to leave the printer unaffected so that the data prints both to the printer and the LED message boards.
Does anyone know of a relatively inexpensive way to split off the parallel signal and send it to both the printer and another computer simultaneously? Since I don't have access to the computer originating the printer traffic, the solution can't be anything which requires me doing anything to that computer, nor do I want to do anything which would affect the functioning of that computer or the printer.
I'm operating under the assumption that once I split that line off, I will have to use a parallel-to-serial converter and read the intercepted data off of the eavesdropping computer's serial port.
Does anyone have any ideas how I might go about approaching this problem?