Why such fat bar code out of the thermal printer?

[4ster]

I still use the 82162A and a plotter module in my 41 to print bar code. (I know, I am a troglodyte.)

I've always wondered why the HP software engineers wrote the code for the thermal printer so that the bar code was so fat compared to that printed in the manuals or created on a plotter? On modern, white thermal paper my printer still prints crisp, high contrast black and white code. It is certainly capable of printing more compact bar code.

Was it a byte restriction in the 41 alpha register or the print buffer? That is the only thing I can come up with.

Just curious.

[rprosperi]

(08-04-2015 01:20 PM)4ster Wrote:  I still use the 82162A and a plotter module in my 41 to print bar code. (I know, I am a troglodyte.)

I've always wondered why the HP software engineers wrote the code for the thermal printer so that the bar code was so fat compared to that printed in the manuals or created on a plotter? On modern, white thermal paper my printer still prints crisp, high contrast black and white code. It is certainly capable of printing more compact bar code.

Was it a byte restriction in the 41 alpha register or the print buffer? That is the only thing I can come up with.

Just curious.

On thermal paper (in particular back in the '80s) there is less precise control of the "thickness" of the printed line, due to paper age, battery levels, moisture, etc. etc. so the only way to reliably get good scans (which is based on the ratio of white to black line thicknesses) was to scale up the size of the printed bar codes, and it worked quite well.

The pre-printed barcodes they published were printed using methods with much finer control of the print size/quality, hence they were able to provide much smaller barcode.

Today, enthusiasts like us use good quality paper, have excellent power sources, and are quite careful to do this "right". Back in the day, HP was targeting just plain old vanilla customers, so had to have a solution that was reliable under lots of poor conditions.

[TASP]

"Back in the day" I just figured they wanted to sell more paper.




I've managed to replace my Plotter ROM (and it's not in an HPIL module yet) but haven't attempted to print barcode on one of my 82162s yet. And I may not. I'd probably have a better shot of being happy with the results on the Thinkjet.

[4ster]

(08-04-2015 05:32 PM)TASP Wrote:  "Back in the day" I just figured they wanted to sell more paper.

There is that.

My goal is to print bar code on my (serial) HP plotter. So far I've found the HP-IL RS232 daunting to say the least. I'll get there one day.

[TASP]

I have an IL-IB interface, and a 7470 is on the list.

The 'fussy' pen width issue seems annoying, but maybe when I'm actually doing it it won't seem so rinky dink . . .

[Sylvain Cote]

I saw your message this morning but could not answer because I was at the office.
I just did a bar code test on my 82162A to confirm what I thought and ...
... the width of the bar code is based on the paper feed skip height.
-> bar code spacer width = paper skip height
-> small black bar = 0 = same width as the spacer
-> large black bar = 1 = double width as the spacer
Sylvain

[4ster]

Thank you Sylvain. To me, that is the answer that makes the most sense.

[TASP]

. . . and always use the black paper . . .