Intermittent black squares printing from Pioneers to 82240B

[Dave Britten]

I considered that, but if it's a timing issue, I don't think it's a mechanical one. Sometimes when the only character on a line is a line-feed (e.g. printing a blank line between amort groups), it will skip that character and not advance the print head/paper at all.

I just did a test with the two printers side-by-side: the A on the left, running on batteries, and the B on the right, running on the external power supply (an original 82241A). Both have relatively new batteries. The A produced flawless output, but the B had four initial character skips (and a misreceived character, because I was holding the calculator a bit too close at first). I never see any of the little broken box characters that would indicate a buffer overrun. It never skips a character in the middle of lines, and I can't find any problem with output from a 48SX or 48GX. So weird.