Measurement Computing Personal488 rev.3.0 For DOS & Windows 3.Xi - Manual (Page 122)

II. SOFTWARE GUIDES - 8. Driver488/DRV 8L. Language-Specific Information
Personal488 User’s Manual, Rev. 3.0 II-107
GET & PUT (for GW-BASIC only)
Users of GW-BASIC and/or Interpreted BASIC can also manipulate two commands not available in
QuickBASIC:
GET and PUT , as detailed in the following paragraphs.
The BASIC INPUT and PRINT statements communicate with Driver488/DRV one character at a time.
That is, the PRINT statement breaks up each command into single characters and transfers those
characters separately to Driver488/DRV, and the INPUT statement reads one character at a time from
Driver488/DRV until it detects the carriage-return and line-feed that marks the end of the line. It is
more efficient, especially for long transfers, to read and write blocks of characters. The
GET and PUT
statements can be used to gain this improved efficiency.
GET and PUT are normally used to communicate with fixed-length random access files.
Driver488/DRV can be accessed as a random access file:
100 OPEN “\DEV\IEEE” FOR RANDOM AS #3
This opens the third Driver488/DRV name, IEEE , for I/O as a random access file with 128-byte
records. (The other two names: IEEEOUT and IEEEIN , are used for PRINT and INPUT ).
BASIC normally limits the number of opened files to 3. Opening additional files can cause a
TOO MANY FILES error. If you should get such an error, you might need to save your program, leave
BASIC (with the SYSTEM command), and reenter BASIC specifying a /F:n parameter. See your
BASIC reference manual for more details.
JPI TopSpeed Modula-2
Use of Direct DOS I/O Devices
Once Driver488/DRV has been installed in your system, it is ready to begin controlling IEEE 488 bus
devices. To show how this is done, we develop a short program, in JPI TopSpeed Modula-2 and
Logitech Modula-2, to control a Keithley Instruments Model 195 digital multimeter. The techniques
used in this program are quite general, and apply to the control of most instruments.
In order to simplify programming Driver488/DRV with Modula-2, the following files are provided on
the Driver488/DRV program disk:
•
IEEEIO.MOD : Communication routines for Driver488/DRV.
•
IEEEIO.DEF : Declaration file for IEEEIO.MOD .
The actual demonstration program is contained in K195DEMO.MOD . A Modula-2 version of the
keyboard controller program is also included.
Logitech Modula-2
Use of Direct DOS I/O Devices
Once Driver488/DRV has been installed in your system, it is ready to begin controlling IEEE 488 bus
devices. To show how this is done, we develop a short program, in JPI TopSpeed Modula-2 and
Logitech Modula-2, to control a Keithley Instruments Model 195 digital multimeter. The techniques
used in this program are quite general, and apply to the control of most instruments.
In order to simplify programming Driver488/DRV with Modula-2, the following files are provided on
the Driver488/DRV Program disk:
•
CHARDEV.MOD : General purpose character device I/O routines.
•
CHARDEV.DEF : Declaration file for CHARDEV.MOD .
•
IEEEIO.MOD : Communication routines for Driver488/DRV.
•
IEEEIO.DEF : Declaration file for IEEEIO.MOD .
The actual demonstration program is contained in K195DEMO.MOD . A Modula-2 version of the
keyboard controller program is also included.