random errors as well as any systematic changes that may have occurred. 
3.9 GENERAL 
As may be surmised from the above presentation, the STARS software 
package is quite sophisticated and extensive. Accordingly, every effort 
has been made to make the package easy to use. In particular, extensive 
use has been made of computer generated prompting and computer graphics. 
A photogrammetrist with a few days of training and practice can become 
quite proficient in the use of the program. However, the program is 
designed so that it can be operated routinely by a technician with only 
occasional supervision by a photogrammetrist. 
4.0 THE COMPUTER SYSTEM 
As a system, STARS has had to wait for release until a suitable computer 
emerged on the market. The writer's philosophy in formulating STARS was 
that a dedicated computer had to be part of the system. Otherwise, energy, 
resources and valuable time would have to be expended in converting the 
software to run on various computers at various facilities. Moreover, in 
such a situation planned use of computer graphics would entail great, if 
not insurmountable, difficulties. Finally, training, maintenance of soft- 
ware and implementation of future enhancements would be severely inhibited, 
a clear disservice to clients. In view of such considerations, there was 
no practical alternative but to include a suitable, dedicated computer as 
an integral part of STARS. 
The basic requirements of the computer system for STARS were that it 
had to consist of a desktop unit with at least 256 K bytes of memory, at 
least 5 megabytes of fixed disk, a floppy disk, a graphics terminal, a 
pair of RS-232C ports, a parallel output port for a printer, a FORTRAN 
compiler, and a graphics printer with a speed of at least 150 cps. Equally 
important, it had to be quite powerful with computational speed approaching 
those of higher-end minicomputers. Finally, and of utmost importance, the 
system had to be relatively inexpensive so that its cost would be comparable 
to that of converting and installing STARS software to operate on a typical 
mainframe computer. This put an upper ceiling of about $15,000 on the 
computer system. At such a price the computer could be regarded as being 
essentially 'free' and could be 'bundled' into the software (a drastic 
change from only a few years ago when it was commonplace for 'free' software 
to be bundled into a computer system). 
As of early 1981 about the best the market had to offer against the 
above requirements for capacity and performance ended up costing over twice 
what was acceptable. However, in the summer of 1981 WICAT Systems of Orem, 
Utah, announced their System 150, a 16 bit desktop microcomputer based on 
the Motorola 68000 microprocessor. This system turned out to meet or surpass 
all of GSI's requirements. After a thorough investigation, the WICAT 150 
was adopted for STARS and upon delivery of a unit to GSI in December 1981 
installation of STARS software commenced. Completion is scheduled for June 
1982, 
In the basic configuration adopted for STARS, the WICAT 150 has the 
following characteristics: 
256 KB of Dynamic Parity RAM (expandable to 1.5 MB) 
10 MB 5%" Winchester Disk