HP 110 "garbage" on screen

[ThomasF]

Sorry if I was unclear.
I was thinking about rows and columns in the ASCII table.
Ie look at this one. Rows are the lower 4 bits of the character code, and columns the upper 3 (or 4) bits. And with bit 6 failing, column 4-7 are unreachable, just as the problem seems to indicate.

The "Line 4 Column: 21" is the text on your screen-shot if I "decode" it correctly. Maybe that is the current cursor position when you are writing on the screen (you added some lines with characters).
I was just trying to prove that this also indicates that the problem really is with bit 6, since that makes more sense then the "garbage" on the screen ...

Cheers,
Thomas