SOFTWARE 
The hardware-oriented software, i.e., the I/O routines for Planimat 
‘Controller and terminal, have been written in MACRO-11 assembly 
language code, the application-oriented programs in FORTRAN IV. 
MACRO subroutines 
These represent the software interface between the application pro- 
grams, on one hand, and the DRI1-C and the terminal, on the other 
hand (fig. 1). Their functions are: 
(a) recording of coordinates (ENCOD) 
(b) steering the motors (STEP) 
(c) writing to and reading from the terminal (KEYBO).. 
The subroutine ENCOD transfers the contents of the three encoder 
buffers to specified variables in the application programs. The 
subroutine STEP transfers the number of steps, computed by the 
application programs, to the motor buffers. A check is built in to 
avoid sending new pulses to the motors before ending the current 
movement. The subroutine KEYBO supports communication through the 
terminal. It handles the display of information for the operator, 
data and command entries by the operator, and interrupts. Interrupts 
are generated by pressing a key on the terminal's keyboard. Selected 
keys lead to certain actions. The main actions are remeasuring a 
point or ending a certain type of data collection. 
Application programs 
The hardware and hardware-oriented software described above can be 
used for a wide variety of applications. Each requires a specific 
set of programs. Fig. 1 shows the main modules for CS. 
The interactive program "selective sampling" supports the collection 
and storage of supplementary data (S-data). It controls digitising, 
coding and indexing of features, and cancellation or storage of 
data. Options provided are: stationary/dynamic mode, isolated 
points/strings, open/closed lines, and single/multiple nesting of 
closed lines. 
The S-data stored on magnetic tape can be verified by producing a 
check plot off-line. For subsequent PS, the S-data are converted 
from vector to raster format. Output of the batch-type program is a 
file on disk containing per point of a gridded line or per isolated 
point: Z, the matrix indices I,J, and the indices of the patch it 
belongs to. Gridding is done into the finest grid cell used in PS. 
The program "progressive sampling" consists of several modules for: 
- input of sampling parameters (model limits and patch size, maximum 
number of sampling runs, threshold for the 2nd height differen- 
ces) 
- filling the patch matrix with the S-data of the current patch 
- guiding initial sampling (zero-run, et [ED 
- analysis of the matrix after a sampling run is completed: 
the second difference of measured heights is checked against the 
threshold. Columns and rows are searched for point triplets 
(c£,[3]) 
25 
ON