		  Overview
		  --------

When Dolby SR*D film is played through a Digital Processor (DA10, DA20, or 
CP500) the information on the Dolby Digital soundtrack is converted into analog
audio.  With a DA10 or DA20, that audio is then fed into a cinema processor for 
playback in the theater.  The Digital Processors have been designed to also 
provide additional data about the soundtrack.  This information is available 
at the serial port, and includes block positions, error rates and other 
relevant parameters.  The DRAS system uses this additional data to determine 
the reader alignment.


		  Viewing Reader Alignment from Running Film
		  ------- ------ --------- ---- ------- ----

Make sure that all of the equipment is off, and that the serial output 
connector of the DA10/20 or CP500 is connected to a  computer com port with a 
9 pin serial cable (not null modem).  Turn on the computer.  After it has 
booted, turn on the DA10/20 or CP500.  (some computers will not boot if the 
Digital Processor is powered up and connected)  

To start the DRAS program, go to the DRAS directory by typeing CD \DRAS.
Once in the dras directory, type DRAS.  This assumes that the com1 port of 
the computer is connected to the DA10/20 or CP500.  If you want to use the 
com2 port, type DRAS /com2.

Thread a known good reel of film through a Dolby Digital Film Reader.  A 
diagram of the film path is printed on the film reader.

Turn on the projector motor.  Highlight the menu item Run.  Press Enter to start 
the DRAS analysis.  If the film is good, the reader is aligned, and the DRAS 
system is working correctly, then the user should see a Dolby Reader Alignment 
Screen that is displaying indications of a good quality film, i.e. the bar graph 
will be updated with green elements and the boxes with the numbers will be blue 
or green.


		  GLOSSERY OF TERMS
		  -------- -- -----

Azimuth                 Angle of block with respect to film direction
Basement Reader         Digital reader located in soundhead area
Cat. No. 699            Early Dolby penthouse reader
Cat. No. 700            Current Dolby penthouse reader
CP500                   Cinema Processor with digital playback capability
DA10                    Early Digital Processor for playback of SRD film
DA20                    Current Digital Processor for playback of SRD film
Digital Processor       DA10, DA20, or CP500D
DRAS                    Dolby Reader Alignment Software
DFSP                    Digital Processor (Digital Film Sound Processor)
Histogram               Distribution of bit center voltage levels
Lateral Position        Block Position as measured in cross film direction
SRD                     Dolby Digital film sound format
Vertical Jitter         Equivelent to flutter
