Optional features include the forementioned transform- 
ations and calculations; a 40 key command touch 
pad which allows input of any ASCII character to the 
controller; a 32 character LCD display for coordinate 
display, operator prompting, and checking current 
operating parameters; a battery backup feature which 
protects coordinates and operating setups in case of 
power loss; additional buffer memory; user-definable 
ASCII formats; and parameter storage for future use. 
o APACHE electro-optically Aided Scanning Cursor 
The APACHE is a revolutionary development in the 
manual digitizing industry because it allows the user 
to increase his digitizing productivity by tracing 
faster and more accurately than with any previous 
hand-held cursor. The APACHE's unique cursor 
contains a miniature television camera which optically 
measures the position of a line within its 0.1 inch 
bullseye reticle relative to the position of the center 
of the line. The microcomputer in the APACHE then 
calculates the true position of the line's center 
eliminating errors due to imprecise positioning of the 
cursor by the user. This allows the user to trace 
more quickly (particularly on curved lines) with 
consistently higher accuracy, while eliminating 
operator induced error and increasing productivity. 
"The APACHE combines the best parts of both the manual 
and the automatic process, while avoiding the dis- 
advantages of either. The operator moves along a line, 
and, since there is no concern about accuracy, the 
movement can be much faster than with the traditional 
manual method. When one encounters an area that 
cannot be handled automatically without the possibility 
of error - for example gaps in the line, intersections, 
or very thick lines - the correcting mode is disabled 
and the manual mode takes over." (Poiker, 1983) 
o MICRODIJ 
Use of the MICRODIJ Digitizing Software can be 
considered intelligent because it takes the burden of 
interfacing to the personal computer environment off 
the shoulders of the user. MICRODIJ is a software 
package designed to be used with any ALTEK DATATAB 
Digitizer in conjunction with.an AC30, AC35, AC36, 
AC40, or APACHE controller.  MICRODIJ takes input 
from the controller and provides direct data storage 
on disk or magnetic tape. It can also direct the 
data out a serial port.  MICRODIJ provides much of 
the same computational features as the ACA4O. In 
addition to area and length, the volume of objects 
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