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1.2 WORKSTATIONS 
A typical workstation is a stand-alone unit with a 32- 
bit CPU running under an engineering operating 
system like UNIX. Workstations offer high 
performance graphic capabilities and network 
facilities. When tied in a network, workstation users 
have access to huge data storage capacities and 
mainframes. 
Since 32-bit personal computer with integer 
performance of 1 MIPS or more and running under 
UNIX operating systems have been available, the line 
between PC and workstations is overlapping. 
Differences are in the main memory of PCs (up to 8 
Mbytes) and workstations (up to 32Mbytes) and the 
adaption of RISC  microprocessors. The most 
important performance parameter for technical 
applications is the millions of floating-point 
operations per seconds (MFLOPS). An IBM RISC 
System/6000 for example is working with 10.9 
MFLOPS. 
Because of the convergence of workstation and PCs, 
the key for successful software development is the 
use of standards like high level languages and utilities 
for easy transportation of special application 
packages, like close-range photogrammetry, to 
different hardware platforms to benefit from the 
power of the machine. Running technical programs in 
a DOS compatibility box with all the limitations of 
the DOS operating system on a powerful workstation 
is not what I understand as transportation. 
1.3 GRAPHIC STANDARDS 
High performance graphic subsystems do not have 
such a standard like hardcopy units for graphical 
output. All vector plotters today can understand 
Hewlett-Packard's Graphic language. Therefore, 
plotting programs can be written widely device 
independent. 
In the PC world there are only two video standards: 
IBM'Ss video graphics array with a resolution of 640 x 
400 pixel and 16 colors and the IBM 8514/A 
standard with a resolution of 1024 x 768 pixel. A 
program written under consideration of these 
standard is running on all machines which support the 
specifications, and they exist in large numbers. Most 
graphic boards with higher performance can also 
support VGA or 8514. 
To benefit from higher sophisticated graphic boards, 
the software developer must have access to device 
drivers. In special cases, he has to write his own 
drivers. If he is using a software interface like GKS 
or PHIGS, the hardware supplier will deliver the 
requested tool. 
2. PRESENT SOFTWARE STANDARDS 
2.1 OPERATING SYSTEMS 
2.1.1 DOS 
MS-DOS is the leading operating system for personal 
computers. Today, there are over 60 million DOS 
machines running worldwide. DOS is a single user, 
single tasking system which can run all applications 
written for 640 Kbyte Intel-based PCs. But the 640 
KByte memory limitation is a great disadvantage for 
the more sophisticated end user. Two kinds of 
software products are available to overcome this 
limitation: 386 control programs and DOS extenders. 
Control programs like Microsoft Windows/386, 
DESQview or VM/386 allow the 1386 to run various 
PC-DOS programs simultaneously in the accessible 
RAM area. 
A control program is not able to offer enough 
memory for programs like a bundle adjustment. A 
powerful tool for applications like this is the Phar 
Lap 386 DOS Extender. This software loads and 
executes 80386 protected mode programs and 
handles access to DOS system calls. The Phar Lap 
386 DOS Extender supports a wide range of various 
32-bit compiler. 
Some modern 32-bit Compilers include also functions 
to run 386 protected mode programs under DOS. 
2.1.2 OS/2 
The operating System/2 was introduced to replace 
MS-DOS and the related limitations. OS/2 offers 
several advantages over DOS such as multitasking, 
background processing, dynamic linking of software 
modules during runtime, access to much more 
memory than 640KByte and others. 
But OS/2 needs more memory and harddisk space. 
Because of the delay in providing the promised 
features at the announced schedule, OS/2 has not yet 
succeeded. It is possible that the typical PC user has 
no real requirement for the OS/2 system. But if OS/2 
is available with all it's features, it can be a system, 
which is competitive to UNIX.