Need help with Futaba VFD protocol

EDIT: clarified title

Hi, noob here.

I just got my hands on my first Arduino and i have been toying with all the stuff i can do with it.
Right now, i'm trying to use a display to get feedback from the "projects".

image's not mine

The display is a serial one, gotten from an IBM surePOS 500, with four pins: +5v, signal, vfd_present and ground. vfd_present is used by the POS to know if the VFD is installed.

The VFD is a Futaba M202MD15B (20x2 chars of 5x7+1 dots) for which no help have come from Google, i only get ebay-like sites as results and don't have almost any documentation for it; there's no mention of such VFD on Futaba site and the similar models i've found there are different enough as to be unusable because the pinout changes. However there are some commands to talk to it in a document from IBM about the POS itself (page 56 and on here) but i can't make heads from tails out of them.

I know it works because i got POS software writting to it on Windows XP using java, but i no longer have the POS to further test.

I have the VFD wired to the arduino already (using a 2N7000) and have tried to write to it using many libraries like wire, softwareSerial and even sending bites and bytes with print() and write() and it just displays garbage each time i send something.

Unofficial sources (some random post in some forum i can't find again) say "M" series VFDs use a custom protocol but i wouldn't know.

There are 2 ICs that can't be made out on the picture: Philips P87C54SBBB and TI 28D9J7K.

I like this display a lot because it only takes one wire from the arduino.
How can i talk to it?

Thanks in advance!

Looks like, page "2/14" it expects 'real' +/- RS-232 signalling (not just "logic level"

Thanks for your input Pancake.

The model you linked is different, it uses 4 data lines (2 Rx + 2 Tx) + power.

Mine was connected to a single +5v line (as per the POS manual i linked)

Oink, missed that.
It's a lot more complicated than the other (A version).
The APA codes and all of that - oh, dear.

Ok so your answer got me googling.

Appendix G of the manual i posted mentions "VFD commands". Right after that section there is one called "APA Commands" which looks exactly the same as "VFD Commands" to layman eyes.

However, according to the same manual on page 30, it says the POS supports an APA display mounted externally and independently of the 2x20 (they call it) that's integrated, so mine's not APA.

Further more and funnily enough i just stumbled upon a Q&A on IBM website; the question is "SurePOS 500: Where can I find the device commands used for interacting with the SurePOS 500 2x20 customer display?" and IBM goes in a lot of detail on how to do just that!

I guess im gonna go wash cars or something else because for the life of me i just can figure it out! :blush:

Can anyone shed some light?

I know that this post is too olf but I started from here for ask you my same problem.

I've got the same display but no information about wiring with arduino or some code just only for print hello world.

Any help ?