SAMPLE: Measuring System Timings by Using Printer Port

• Microsoft Windows Software Development Kit (SDK) for Windows version 3.1

SUMMARY

Use Your Printer Port to Measure System Timings

Herman Rodent Microsoft Developer Network Technology Group

Created: January 4, 1993

If you need to measure interrupt latency, interrupt-service-routine execution time, or procedure call overhead---or if you just plain want to know why your application is so slow---here's an article that describes a simple way to use a printer port and an oscilloscope to do timing measurements.

If you don't know what an oscilloscope is, you can either stop reading now and return to struggling with your code, or look forward to renting a new toy to play with.

PPDEBUG.ASM is an assembly language code module that provides C-callable services to set and clear the bits on the printer port.

PPDBG.INC is an assembly language include file that provides macros to assembly language code modules.

These modules demonstrate the concepts discussed in the "Use Your Printer Port to Measure System Timings" technical article on the Microsoft(R) Developer Network CD.

Download PPDEBUG.EXE, a self-extracting file, from the Microsoft Software Library (MSL) on the following services:

• Microsoft Download Service (MSDL)

        Dial (206) 936-6735 to connect to MSDL
        Download PPDEBUG.EXE (size: 32656 bytes) 
  

• Internet (anonymous FTP)

        ftp ftp.microsoft.com
        Change to the \SOFTLIB\MSLFILES directory
        Get PPDEBUG.EXE (size: 32656 bytes)