Direct port access in Win95 with Delphi 2.0

Question:
We have a specialized ISA bus hardware card that has relays, etc. on it that are accessed by writing or reading to the PC’s I/O ports.

How can I port our specialized application to Windows 95 if Windows no longer supports direct port access? Surely there must be a way to do this; otherwise, how could a scanner or a machine-tool controller, or any specialized hardware function? How does Windows talk to the physical ports of a graphics card?

If the answer is a VBX or DLL, isn’t there a generic way of allowing a program to write to a given I/O port or receive the data from an I/O port without writing a complex DLL with all the bells and whistles?

Answer:
I’ve not had to do this myself, but from what I gather, you can open a portwith the CreateFile WinAPI function and read and write data to the port thatway. I suggest getting a book on the WinAPI.

Share the Post:
Share on facebook
Share on twitter
Share on linkedin

Overview

Recent Articles: