Print differences between HP82143A and HP82162A?

[Christoph Giesselink]

At the moment I'm playing with the HP41 PRPLOT program on V41 printing the same setup on different virtual printers.

One printer simulation is my HP82240B printer simulation in HP82143A mode, the other the HP82162A in pyILPER.

So far I assumed that the real HP82143A and the real HP82162A printer use the same printing mechanism (build of components) inside and so the printout should be equal. Can anyone confirm this with real printers.

My HP82240B printer simulation in HP82143A mode use a character height of 7 pixel and a line gap to the next character below of 4 pixel.

The HP82162A printer in pyILPER use a character height of 7 pixel and a line gap of 6 pixel so the same printout is higher.

What is the correct line gap value?

First of all, I know that the printer pixels are not quadratic, but I'm only interested into the ratio of character height to line gap height. I have a photo with the printed character set of a real HP82143A. In this photo the character has a height of 81 pixel, the line gap a height of 45 pixel.

Translated to 7 pixel character height: 81/7=11.57, 45/11.57=3.89 -> rounded to 4

So my assumption for the HP82143A mode seem to be ok. So it's not necessary to make a print on the HP82162A, but a photo of a 3 or 4 line print of a HP82162A would be interesting.

In pyILPER 1.8.8 file pilhp82162a.py is a constant definition of

PRINTER_CHARACTER_HEIGHT_PIXELS= 13

for 7 pixel character height and 6 pixel gap (7+6=13).

To reduce the gap to 4 simply change the definition to

PRINTER_CHARACTER_HEIGHT_PIXELS= 11

then the printout of HP82240B in HP82143A mode and HP82162A in pyILPER looks identical.