1250 
MONITORING 
TO USE TERMINAL, KEY IN YOUR STAFF C00E.4 
by the Sigma-3 monitor. Each of these process- 
ing areas has its own priority level and an asso- 
ciated queue stack. The queue stacks are used to 
control orderly loading and execution of multi- 
ple requests. 
The non-resident foreground area is for the 
slowest processors. Processors delegated to this 
level have execution times on the order of min- 
utes. They perform such jobs as communication 
with the second tier and Fourier analysis of 
pressure and flow waves. The Sigma-3 monitor 
handles queuing of this area and controls load- 
ing and unloading of the individual processors. 
Each of the three semi-resident areas exe- 
cutes at its own distinct priority level. The 
queuing and loading from the RAD of the nc^- 
core processors for these areas are handled > a 
foreground program. Processing times range 
from milliseconds for processors assigned to the 
highest priority semi-resident area to about a 
minute for processors assigned to the lowest 
priority semi-resident area. 
Whenever a processor is requested and the 
core area associated with the semi-resident area 
to which it is assigned is not in use, any lower 
priority processors are interrupted, the high 
priority processor is loaded and executed, and 
then execution of the lower priority processor is 
continued. The result is a response hierarchy 
commensurate with the complexity of the jobs 
being performed. 
Using the Terminals 
Figure 3. — Initial message. 
REFERENCE FILE to see if the staff code is 
in fact entered. If the code is not a staff code, al- 
ready entered in the REFERENCE FILE, the 
diagnostic message, INVALID CODE, is gener- 
ated and the user may reenter a correct staff 
code. If it is a valid staff code, the message 
stored in the REFERENCE FILE is displayed 
on the TEC screen (Figure 5). At the same 
time the computer stores a computer code corre- 
sponding to S22 in the DAYFILE to make this 
part of the context of any data that follows. The 
user next keys in the SGPT test number, T41037. 
(Figure 6). The computer checks the REFER- 
ENCE FILE to see if the number T41037 is 
valid. It then displays the message stored in the 
We are now in a position to describe how a 
user can execute a typical computerized test 
with the aid of the TEC terminal. We will de- 
scribe the user's actions and the functioning of 
the various elements of the computer system as 
a typical biochemical test is performed. The test 
we have selected is the test T41037 for Serum 
Glutamic Pyruvic Transaminase (SGPT) com- 
putation. The reference file entries for this test 
were described in Table III. 
When the user arrives at an unused terminal, 
a message to key in his staff code is displayed 
(Figure 3) . The user keys in his staff code (the 
keys S, 2, 2 followed by the transmit key) (Fig- 
ure 4). The computer first checks to see that a 
staff code has been keyed in. It then checks the 
TO USE TERHIHAL, KEY IN YOUR STAFF CODE i 
S22_ 
Figure 4. — Entering staff code. 
