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???
12/12/05 23:16
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#105099 - NT - not quite
Responding to: ???'s previous message
Charles Bannister said:
The evolution of the inp and out function have been extended to visual basic. See this web site for a solution. http://www.logix4u.net/inpout32.htm

This looks like a jolly useful utility for all those people wanting to control the PC Parallel port, directly-access the PC's UART registers, etc, from NT-based Windows versions (NT, 2000, XP,...)

However, I don't think the description of the problem is quite right:
Logix4u.net said:
Whenever the operating system find that a user mode program is trying to execute such instructions [IN, OUT] the operating system stops execution of those programs and will display an error message.

The OS will not (necessarily) just crash the application:
The application is actually running in a Virtual machine; so these IN and OUT instructions are "trapped", and handled by the OS in software.
This is why so many such applications fail on NT-based systems - because this software emulation completely destroys the timing.

Thus the problem is not (always) that IN and OUT simply cannot be used; rather, that they no longer directly access the hardware and therefore the timing is nothing like it was for direct access.


List of 33 messages in thread
TopicAuthorDate
Add on card programming            01/01/70 00:00      
   please clarify            01/01/70 00:00      
      RE: please clarify            01/01/70 00:00      
         (E)ISA addressing            01/01/70 00:00      
            IOW and IOR            01/01/70 00:00      
               not explicitly            01/01/70 00:00      
                  IRQ in EISA slot            01/01/70 00:00      
                     interrupt            01/01/70 00:00      
                        QBASIC programming            01/01/70 00:00      
                           reply            01/01/70 00:00      
                              DIP Switch Address Setting in EISA card            01/01/70 00:00      
                                 DIP switches...            01/01/70 00:00      
                                    card design enclosed            01/01/70 00:00      
                                       comparator            01/01/70 00:00      
                           QBASIC live and well.            01/01/70 00:00      
                              NT - not quite            01/01/70 00:00      
                                 timing in Win?            01/01/70 00:00      
                              QBasic Lives!!!            01/01/70 00:00      
   refer to 'Barry B Brey'            01/01/70 00:00      
   EISA Bus interfacing            01/01/70 00:00      
      beware if (E)ISA bus books            01/01/70 00:00      
   Try this?            01/01/70 00:00      
      Power resistor selection            01/01/70 00:00      
         dont do it            01/01/70 00:00      
            LM317 is an option            01/01/70 00:00      
               Wasteful!            01/01/70 00:00      
                  if op can...........            01/01/70 00:00      
                     Power!            01/01/70 00:00      
         basic Ohm's law            01/01/70 00:00      
            Trouble shoot            01/01/70 00:00      
               heating            01/01/70 00:00      
                  Reply : Heating            01/01/70 00:00      
                     if you refer to D4 then            01/01/70 00:00      

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