EUGENE F. URETZ, JOHN A. MCCLARY AND STEVE MORGAN 
1245 
experiments, acquiring data, and entering this 
data into the, computationally, more powerful 
FIS system. 
Facility personnel "converse" with the 
Sigma-3 system by means of TEC alphanumeric 
terminals distributed throughout the facility. 
Using a simple language developed for the pur- 
pose, they are able to acquire data from lab in- 
struments and sensors. They may also enter 
data values from the terminal itself. Acquired 
data or computed results may be displayed on 
the TEC terminals themselves or on Beehive 
Alpha-21 graphic displays. Data is stored on the 
system disc for later transmittal to the second 
tier. 
The system is designed to allow all terminals 
to be operated simultaneously with response 
times commensurate with the complexity of the 
job being performed. 
The system also acts as a high speed terminal 
for remote entry of batch jobs into the remote 
system. Cards are read and transmitted via 
data set to the remote system and job output is 
transmitted to the Sigma-3 via the data set and 
printed on the Sigma-3 line printer. Data can 
also be transmitted to the remote facility by the 
keypunch, card reading route. This method of 
data acquisition is used on tests not yet imple- 
mented on the terminal system and as a back-up 
method for all data entry. 
SIGMA-3 HARDWARE 
The facility's on-line computational equip- 
ment consists of a Xerox Sigma-3 and a number 
of associated hardware elements (Figure 2). 
The Sigma-3 has 16,000 16-bit words of random 
access memory and twenty distinct hardware 
interrupt levels. Input-output is through eight 
direct memory access channels or twenty-eight 
16-bit digital input-output channels. 
Attached to the direct memory access chan- 
INSTRUMENTS. 
COULTER COUNTER 
RADIOMETER BLOOD GAS 
300N SPECTROPHOTOMETER 
DENSITOMETER 
A/D 
CONVERTER 
WITH 
MULTIPLEXER 
PHYSIOLOGICAL 
SENSORS 
CARD 
READER 
201 A3 DATA 
COMUNICATION 
REMOTE SITE 
BEEHIVE 
GRAPHIC 
DISPLAYS 
TEC 
ALPHANUMERIC 
TERMINALS 
LINE 
PRINTER 
I 
ASR-35 
TTY 
I 
DIGITAL INPUT 
OUTPUT 
CHANNELS 
DIRECT MEMORY ACCESS CHAN^^ELS 
RAPID 
ACCESS 
DISC 
(RAD) 
I 
XEROX SIGMA 3 COMPUTER 
DIGITAL INPUT 
OUTPUT 
CHANNELS 
Figure 2. — On-site facility computer hardware. 
