I have four IBM POS VFD Customer Displays aka "Pole Displays" This is the one attached to various IBM electronic cash registers that shows the customer the price of each item as it is rung up and then the grand total. It has two lines of twenty characters in flourescent blue or green. These particular displays are IBM part number 61P5766. They are beautiful displays, highly readable and from what I understand are very reliable. I would like to be to use them in some PIC projects but there is a problem. I can't find information on how to make them work. They have a four pin jack in the bottom. They have a Futaba VFD module inside and that part number is M202MD08A. Futaba will not give out any information as they say the design is IBM property. This is what I've been able to figure out so far:
The suppply voltage is 12VDC on the two outer pins. Applying power results in a display of "U001" after about three seconds. This I read in an IBM document, indicates the initialization/self test was successful and the display is waiting for communications.
There is a A176B RS-485 transceiver on the display circuit board and that is the equivalent of the TI SN75176. So I figure it must be using RS-485 electrical communication protocol (differential pair). Thus I figure the two inner most pins on the connector must be the so-called AB pair that the signals are sent on. I have tried hooking up a LTC485 transceiver chip to the output of my PIC 18F452 serial port and sent a variety of codes via pins 2 and 3 on the display connector. I tried to display text on it, initialize it and clear the display all to no avail. I am using a comm setup of 9600 baud, eight bits, no parity and 1 stop bit on the PIC. I've also tried 2400 and 19200 baud, even parity, no luck. I am using the PIC hserout command. This is driving me absolutely bonkers. I don't know if I need enable the receiver or not but I did and there was no success. What I am wondering is if IBM has special codes in its POSS drivers that unlock this device for communications. I guess if someone had the source to the "customer display" section of the POSS drivers I could figure it out, but I can't even find any information about where such programmers hang out on the net. I would be most appreciative for anyone that might help. These displays would be great for all sorts of projects and are readable even in bright light. With the RS-485 protocol they should be ideal for remote displays using a twisted pair wiring at hundreds if not thousands of feet! They have been available from time to time on eBay for $20 US plus shipping, brand new in the original IBM box! I WILL SEND ONE OF THESE UNITS TO THE PERSON THAT CAN PROVIDE THE INFORMATION THATS GETS IT UP AND RUNNING AS LONG AS THEY ARE IN THE CONTINENTAL US! Please help me!
Sincerely , Bob