% of the 
published Knowledge 
  
   
  
  
  
ee M T Sic T T T um 
DE = doc units 
Number of evaluated Journals 
Figure 8 Figure 9 
as shown, can also be used by external customers against payment. 
I think I should say something about expenditure and costs. For installing and 
running a data base costs arise for the following: 
*Hardsware, 
*Own input.performance, 
+ Tape services. if . vanted, 
*ti:Storag e, 
"Software, 
+ Process. ing, 
"Maintenance for hardware, 
+ Maintenance for so ftwaroe. 
For a system like STAIRS/VS you need a main frame computer with a minimum of 
1 megabyte memory like IBM 370. Costs can be obtained from the manufacturer. 
For self-produced data base and documentation units, respectively, the input ac- 
tivities are a big cost factor due to costs for staff. One person performs an 
input of 24 prepared documentation units of average length per day. 
For tape services an estimate is 25 US$ up to 100 US$ per 100 doc units on tape. 
To illustrate the storage costs, I show Figure 11. The yellow curve, here in log. 
scale, shows values for big storages of around 1 to 2 US$ per megabyte and month 
for the time being. 
The table on Figure 12 compares large capacity storages (magnetic discs) of se- 
veral suppliers. Capacities are between 1000 and 3000 megabyte per unit. Smaller 
storage like various Winchester units of a storage space of 1 to 10 megabytes 
have storage costs about 30 to 59 times higher. But they cannot be used by big. 
capacity (hohe Mächtigkeit) reirieval systems. 
Costs for software addenda after installing (primary use) will be relatively 
low. 
The processing costs depend on the frequency of online use and will be lower per 
search the higher the frequency is. It is difficult to give you figures for that. 
Erb 5