12 Apr
2024
12 Apr
'24
6:21 p.m.
On Apr 12, 2024, at 7:48 PM, Van Snyder via cctalk
<cctalk(a)classiccmp.org> wrote:
... The other was to print on its "whippet"
printer, a very fast electrostatic printer that put soot onto a thermal
paper that was then heated to "fix" it. There was a huge variac under
the printer to adjust the heater. The perfect setting was between two
windings. Too cold and the soot fell off. Too hot and it was melted and
smeared into an almost illegible mess. But it was very fast -- and only
80 columns wide. It was about the size of a KSR-33.
Different beast, but it reminds me of an electrostatic plotter we at on the U of Illinois
PLATO system. That one was by Versatec, either 11 or 17 inches wide (I forgot), 300 dpi,
pretty sure it used wet toner. It also used a chain drive for the paper feed, which had
enough backlash that starting and stopping would produce visible irregularities in the
output. So I wrote a driver for it that did overlapped I/O to avoid that problem. (File
I/O directly from a PPU program, lots of fun!)
With that, it did an awesome job printing musical scores.
paul