HP 7470A Interfacing And Programming Manual page 102

will check the proper bit of the status byte. Insert as line 110 or line
1010 a suitable BASIC read statement to read the status byte into a
variable called Status.
100 PRINT "OS;"
110 I STORE STHTUS BYTE IN Status
120 Status=INT(Status/2) !SHIFTS BITS RIGHT ONEPOSITION
130 Status=INT(Status/2) !SHIFTS BITS RIGHTHGHIN
140 Status=Status MOD2 !THIS RESULT IS 0 IF LSB NOT 1
150 IF Status=0 THEN100
180 PRINT "OD;" !SEND OD SINCE POINT HVHILHBLE
1000 PRINT "OS;"
1010 I STORE STHTUS BYTE IN Status
1020 Status=INT(Status/4) !SHIFTS BITS RIGHT2 POSITIONS
1030 IF Status=INT(Status/2)*2 THEN1000 !1sb NOT1
1040 PRINT "OD;"
On some HP computers with an I/O ROM, the following three lines are
equivalent to lines 100to 150of the first program segment shown.
2000 PRINT "OS;"
2010 !THIS IS THE STHTEMENT TO REHD THE STHTUS
2050 IF BIT(Status,2)=0 THEN2000
In many applications, a large number of points need to be digitized.
When the computer is used to monitor bit position 2, the points may or
may not be processed immediately. In most applications, memory would
be allocated for the total number of points to be digitized. A loop would
be established to process the total number of points, calling the sub­
routine each time to check that a point had been entered. A complete
BASIC program for an HP-85 with an HP—IB interface follows. This
program prints out the 500 points after they all have been entered.
6-6 DIGITIZING