28 May
2009
28 May
'09
10:04 p.m.
On 28 May 2009 at 17:41, Sridhar Ayengar wrote:
I've seen it happen on daisywheels, but I
don't even understand how it
would be possible to happen on a dot-matrix printer. Can you describe
what the output looks like?
Maybe I should shoot a video of one operating. Basically, the head
moves left-to-right when printing the first line and buffers up the
second line. Discarding leading and trailing spaces, the processor
that controls the printer decides if it would be faster to print the
next line right-to-left or left-to-right, based on the position of
where the printhead came to rest when the previous line was printed.
Multipass NLQ dot-matrix printers were always bi-directional ( print
a bunch of dots in one pass and then print on the same line but
offset by a tiny horizontal amount).
The first printer that I ever owned was a Diablo Hitype I with the
OEM 12-bit interface connected to a Processor Tech S100 parallel I/O
card. It was about three monts before I figured out that I could
save a lot of time by printing bidirectionally instead of printing
Teletype-style.
Chuck