3. Electronics Equipment
Outside of the immediate operating area there are four racks of
electronic equipment associated with the drive, metering, readout and
programming requirements of the two measuring tables.
System Operation
1l. Previewer
At the previewing station, the operator clamps the plate upon a
rotary plate support with the fiducial marks (or any two images) roughly
aligned with the axes of motion of the measuring table. During successive
observations of the positions of the two points within the field of view of
his microscope, he uses a vernier control to make half-adjustments of the
plate support, until the two points track within acceptable accuracy. All
translations are controlled by the operator's command inputs to the veloci-
ty-servo drive system.
The operator then translates the plate until the point desired as
the zero of the coordinate system is centered in the field of view. Upon
his command to the programmer the bi-directional coordinate counters
are set to zero. All subsequent translations are monitored cumulatively
by the coordinate metering system and the bidirectional counters. The
condition of the counters is continuously displayed in the visual readout.
Before or after locating an image the operator can insert con-
stants relating to the image into the system via a ten-decade keyboard.
The constants will remain in effect until cancelled by the operator.
When the operator gives a readout command to the programmer
this circuit functions, along with the distributor which it controls, to pro-
duce a data output record in a format governed by the patching of the pro-
grammer plugboard. This output record consists of the keyboard con-
stants and coordinate measurements, punched into an IBM card and printed
on paper.
The previewer is capable of accepting prepunched image cards,
which do not require insertion of keyboard data. For these cases the op-
erator sets the control panel so that the programmer causes the card
punch to skip over the constants fields.
The programmer, upon preset commands by the operator, can
insert special punchings into the IBM card, in specified columns, to modi-
fy the subsequent behavior of the Automatic High Accuracy Comparator,
These modifications permit manual centering of the image, and allow for
substitution of new constants in the comparator.