[rescue] Vector Plotters

[Dave McGuire]

On 10/06/2015 12:31 PM, Richard wrote:
>>     Vector CRTs, however do exist and typically, but not always,
>> make use of storage-tubes for the display.  These are capable of
>> producing perfectly true curves, but are long obsolete.
> 
> Just a small nit to pick: vector displays are capable of producing
> true lines, but most will not draw true curves.  Curves are broken down
> into polyline approximations and send to the tube as a series of vectors.
> 
> ISTR that there were some early analog oriented displays that could
> draw some subsets of curves by encoding the "formula" for the curve as
> an analog voltage from a specific circuit, but this was quickly
> abandoned in favor of approximating the curve as a series of vector
> segments.

  Since we're picking nits, this is the difference between digital
(i.e., quantized) and analog drive, and each is used where appropriate.
 The oscilloscope on my bench draws rather perfect continuous curves,
for example.

                -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA