[cctalk] Re: Odd IBM mass storage systems

[Paul Koning via cctalk]

> On Apr 12, 2024, at 7:48 PM, Van Snyder via cctalk <cctalk@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