Repair manual

2-9
THEORY OF OPERATION
Digital Palette is designed for use with Polaroid 35mm film and
conventional Polaroid color film. However, conventional 35mm films can
be used if their exposure instructions are programmed into the Digital
Palette software. For hardcopy of the computer-generated images, the
Polaroid Pack Film, AutoFilm, and 4 x 5 Film Camera Backs can be used
with their applicable film:
o Autofilm Camera Back - Types 331 and 339
o Pack Film Camera Back - Types 665, 667, 669, and 691
o 4 x 5 Film Camera Back - Types 52, 53, 55, 59
b. Filter Wheel Assembly
The filter wheel assembly has five positions associated with it. They are:
o Film Position 0 - This position is not usually used by the software
driver (host computer); it is a reference point for
the system.
o Film Position 1 - This position corresponds to the red filter.
o Film Position 2 - This position corresponds to the green filter.
o Film Position 3 - This position corresponds to the blue filter.
o Film Position 4 - This position has no filter. It is a blank opening,
used during testing and calibration.
Digital Palette exposures require the positioning of the appropriate
colored filters (red, green, or blue) between the images displayed on the
CRT and the film.
Filter movement is initiated by the host computer. It instructs the
Digital Palette to rotate the filter wheel so that a specified filter is
moved between the CRT and the film.
Memory of the last filter wheel position is maintained by the
microprocessor control circuit on the Logic Controller P.C. Board.
Refer to paragraph D in this Section of the Service Manual for a
functional description of the Logic Controller P.C. Board.
Initially, the host computer instructs the microprocessor control circuit to