Sorry if this is a little off-topic. But you were talking about the BCR... Recently I was messing around with one of these "thin client" pc's that happens to have serial ports. Thinking of using to interface with the m-100 since it has two real serial ports. Anyway, I read that one has to check these since some of the pins on the serial ports of these devices (especially from POS "point of sale") applications might carry voltage for barcode readers. So you might want to disable the hot pins if they carry voltage that might fry your serial port. I don't think this applies to model 100 and similar. I think normally only three of the pins are active. Anyway it's worth knowing.
Regards Dave On Wed, Nov 2, 2022 at 8:49 AM Brad Grier <[email protected]> wrote: > Thanks for that write up and explanation Peter! It was great to open my > email, sit down with my coffee, and learn something new today :) > > --Brad > > On Wed, Nov 2, 2022 at 2:52 AM Peter Noeth <[email protected]> wrote: > >> If your BCR wand came with the instruction book, then the information in >> it is correct. There was a supplemental BCR driver tape, 26-3828 that added >> drivers for Codeabar, Interleaved 2 of 5, and UPC-EAN, that was available a >> few years after the M100 bar code reader was available. It wasn't >> advertised much though, just showed up one day hanging on the wall at my >> local Radio Shack (with Computer Center) store. I didn't get it at the time >> because I didn't have a use for it, but I should have. >> >> A little history ..... Radio Shack licensed the BCR wand from Hewlett >> Packard. It is the same wand as HP sold for the HP-41 calculator, just says >> Radio Shack on it. The LED is dim, and has to be enabled by pushing the >> button on the wand, because it was originally powered by the "coin cells" >> of the HP-41, so needed to be a low power device. >> >> Since it does not have the "ruby tip" that the industrial wands use, >> angle of the wand to the paper barcode is more critical, so the Radio Shack >> recommendation of 10-20 degrees back from perpendicular to the barcode >> label is important. And without a proper lens, it is important to not press >> the wand onto the barcode too hard while reading. Doing so will wear the >> tip, changing the distance from the LED/Photo Diode module to the barcode >> label causing mis-reads due to being "out of focus". That is why Radio >> Shack sold replacement "tips" to be used when you "flat spotted" the wand >> tip from excessive wear. Just soft ABS plastic. >> >> Also, since HP designed the wand to read paper labels, the dim LED >> prevents using the wand effectively on modern UPC codes of food industry >> items, where the barcode is printed on mylar, like potato chip bags. It >> needs a lot of contrast between the light and dark bars to work correctly. >> Works best with black and white bars on "semi glossy" paper. >> >> How it works ..... The M100 driver measures the times between the high >> and low transitions the wand outputs while scanning the barcode. These are >> then compared with a table of "times" for a match. if one is found, that >> ASCII character is then sent to your BASIC program when reading the "WAND" >> device. The driver allows for about a 5% tolerance in the transition times, >> so scanning speed is important. Once you train yourself in the correct >> scanning speed, it works quite reliably. >> >> I have the Radio Shack BCR wand, but only for the completeness of my >> collection. For actual use I use a Unitech MS120-NTCB00-NG wand. This is an >> industrial type in a metal body with a hard "ruby tip" lens. It has >> the same "locking" 9-pin D connector and is "plug-n-play" with the Radio >> Shack wand. Much brighter LED that is always on. It can reliably read the >> low contrast barcodes used in the food industry, even when the dark bars >> are in some color other than black. I use it often for keeping a "food >> pantry" and "wine bottle" inventory database with my Tandy 102. Only >> drawback with it is that the LED draws more current and is always on, so >> while I am "inventorying" the pantry, I usually use an external battery to >> power the computer. >> >> Regards, >> >> Peter >> > > > -- > -- > Brad Grier > > >
