HP82143 Thermal Printer half linestep mod

[Hiwi]

Hi,
i recently bought a HP82143 thermal printer for parts only on ebay. The seller mentioned a little switch on the front but reported an unknown function. The paper advance and battery had to be replaced. He said it is working with minor help, but someone has tried to repair it very unprofessional. (flex cable sharp bent from cabinet, roller damaged with sharp or unsuitable tools ...)

However, I remembered a modification from 1981/82 discussed in the CCD ComputerClub and found the article in "Best of Prisma" issued 1986. The so called half linestep modification.

The meaning of the switch: G=Graphics, N=Normal.

The preowner added not two microswitches, he made two wire contacts on a little breadboard board.

But it is not working anymore. So i replaced it with two standard microswitches. I had to try a lot to get it working, but now it works perfect.

The printer can now print graphics, do landscape printing and print barcodes.

This little Snoopy graphic was from the author Winfried Maschke:
(some pixels are still wrong, because i have only a poor scan and can't recognize all text bytes correctly)

   

Ralf