View Full Version : Bar-code scanner?

Terry Yager
September 17th, 2005, 12:43 PM
Does anyone here know anything about vintage bar-code scanners? I've come across a box of Welch Allyn wands, dated 1985. There are numbers on each one, 28347, but I can find no information on them in webland. They have 25-pin male D-shell connectors on them, with only pins 8, 14 & 15 populated, which doesn't match any serial pinouts that I can think of. I'm hoping to be able to convert them for use on some of the vintage computers I have from that period. The TRS-80 Model 100 and the Epson HX-20 both have barcode interfaces built-in, and the Epson PX-8 has an A/D converter built-in.
I'm wondering if anyone has a clue what the three pins would be for? I'm guessing 3-wire serial signals RX, TX & GND, but there should be no need of an RX signal on an input-only device, and the serial theory doesn't explain where the wand is getting it's power from, so the more likely pinout would be one pin for I/O, another for power, and a ground, but which is which? Any insight into this matter will be appreciated.


September 17th, 2005, 01:51 PM
Sounds like the old NCR Business Mainframes setup (or similar) to me. Something called the DA15F interface.

I believe Welch Allyn used to have converters to allow the scanners to work on more than one machine. (came later in history because of the bigger demand to have barcode readers on the IBM PC).

If that's the case, the following pinout would be what you're looking for:

Pin Signal
--- --------
1 +5 Vdc
2 +5 Vdc
3 ISENSE3 (Input)
4 ISENSE2 (Input)
5 ISENSE1 (Input)
6 ISENSE0 (Input)
8 SDATA (Input)
9 LCLOCK (Output)
10 LENABLE (Output)
11 LOAD (Output)
12 SCLOCK (Output)
13 LSTROBE (Output)
14 GND
15 SSTROBE (Output)

Terry Yager
September 17th, 2005, 02:43 PM
And this would be the signals at the terminal side of the connection? I'm assuming the SSTROBE signal is all the power that the wand needs (I see your pinout has power on pins #1 & 2)?
So this is more like a parallel interface, but with SerialDATA (in) on pin #8? The signals are not like the "normal" RS-232C signals.

TNX for the input, I'll see what damage I can do with this info.


September 17th, 2005, 06:13 PM
Yes, at the terminal :-).

Keep me posted I want to know what this all about.

October 5th, 2005, 02:42 AM
Hi Terri,

Just posting here cause I'm wondering how you did with he 15 pin out I gave you, does it seem to be the right pin out? if so, how's that project going?

Terry Yager
October 5th, 2005, 06:24 AM
That project is kinda on hold right now, been tied up with some other stuff (like making room in the house by clearing out a buncha eBay stuff).