306 
The hardware components are - a POP 11/23 computer of the Digital 
Equipment Corporation(DEC),it has a 
RT-11 operating system and 256 Kbyte memory; 
programs and data are stored on a 20 Mbyte 
Winchester disk,for data transfer a floppy 
disk unit is used; 
- a graphics display,a 19 inch diagonal IMLAC 
screen,with 2048 x 2048 screen addressable 
points,92 key key-board light pen;bit-sliced 
display processor,8086 central terminal pro- 
cessor,64(optional 192)k bytes of RAM,64k 
bytes EPROM. 
The MAPS 300 program is a program for editing graphical data in a data base. 
The system is menu driven and supports 999 layers(levels),so that the user 
can divide easily data into logical groups,which is very useful when 
editing a large data-base or to work with only part of the entire data. 
The layers can be switched on and off as required for editing. 
The software provides routines for : 
- creating files 
- combining of files or layers 
- displaying single layers 
- editing points,lines,attributes 
- place alphanumeric annotation 
- making lines and features parallel 
- squar ing buildings 
- €ross-hatching of polygons 
- window zoom for fine editing. 
The program is able to read all data which is complying with the international 
accepted Graphics Kernel Standard(GKS).The data from the MAPS 200 created 
files is converted to the MAPS 300 format.The entire interactive graphics 
system is ,because of the menu driven programs,user-friendly and easy to 
handle .(see also Klaver). 
4.Combination of Data with MAPS 300 - System 
  
First the files with the recorded data from data acquisition are separately 
displayed on the interactive graphical screen for supervision.The data from 
the DSR-1 are classified and assigned to the related levels,as normally 
it is not possible to assign all data to the correct level during measure- 
ments(see Stampa-WeBel).Digitizer data is reviewed to completeness,logical 
correlation of lines and symbols.After this supervision files of different 
origin are combined in the system.We use the DSR-1 data as base data and 
superimpose the utility data files.So the differences between the photo- 
grammetric-measured data,which has a high accuracy and is based on the 
cadastral survey points,and the information from the utility maps can be 
seen.Now it is possible to measure the position of the point in both files 
and then to decide either to move.the point in the utility file to the 
correct position as shown by the photogrammetric measurements or to 
improve it by check field survey.If we still have terrestrial surveys 
(coordinated points)we load these measurements into the system and adjust 
the data to these values.For all these operations it is useful that the 
program provides the possibility to load selected levels,edit data from 
these levels and then work with other data on different levels,