How can inject a cpu image to a analog camera for POS?

[cavcom 0]

My client has old analog systems with ancient cash registers that have serial ports that run over a flat phone wire to a box for each register above the dvr. The boxes have a input from the camera, an output to the dvr and an input from the flat phone wire that injects the screen information from the register to the dvr. So one box per register. Now there converting all the registers to new Pc pased levono units. My question is how can I inject whats on the screen on the new pc based registers or maybe at the least what there typing on the screen to the dvr? Any help would be MUCH appreciated.

Thanks

Mike

[ssmith10pn 0]

Same way.

The box is just sniffing the data going to the printer and over laying it on the screen.

 

RS232 data only needs 4 wires.

[dexterash 0]

You need to "sniff" the protocol of the old cash registers and, somehow, emulate it in your new setup.