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MS BASIC Forum · Visual Basic

#IAC

7 messages in this thread

#3295From: Mitchell WaiteOct 15, 1991 8:53 PM

There is an area of DOS memory called the IAC (Intra-Application Communication area) that is reserved by the OS for letting programs communicate with eachother. Its at 0040:00F0 to 0040:00FF. If there was a way to reach this from Visual Basic we could avoid the clipboard all together. But I don't know of any way to get VB to communicate with a DOS process that is running. Seems you would have to figure out what task it was then have a DLL talk to it. Perhaps there is an API that can do that. Perhaps Mark will tell us the secret what that Muscle does its PEEK? Mitch There are 2 Replies.

#3368From: Mark Novisoff/MicroHelpOct 16, 1991 5:26 AM

Mitch, The source code to do what you want is in Muscle. The idea is to assign a Windows "selector" that corresponds with a real mode segment. The method used involves two interrupts (not API services) and therefore can't be done with straight VB code. Mark There is 1 Reply.

#3519From: Mitchell WaiteOct 17, 1991 12:08 AM

Thats interesting and makes your product a real deal. When you say the source code you mean the VB code that calls your DLL right? What I wish is that I could buy just the DLL that does the PEEK so I don't have to carry all that extra weight in Kbytes. > The idea is to assign a Windows "selector" that corresponds with a real mode segment. > What is a selector oh wise one? There is 1 Reply.

#3544From: Mark Novisoff/MicroHelpOct 17, 1991 7:30 AM

Mitch, When I say source code, I mean assembly language source too! In Windows a "selector" functions just like a segment. You can move the selector's value into the DS and ES registers and then manipulate data within that portion of memory. Selectors are similar to "handles" in that they don't correspond to a physical memory location. Rather, in protected mode, they tell the processor that it should consult its internal table of physical memory addresses and use the one associated with the selector. Mark

#3389From: Ethan WinerOct 16, 1991 8:26 AM

Mitchel, Be careful using the IAC because you can't know if another program is using it too! –Ethan There is 1 Reply.

#3520From: Mitchell WaiteOct 17, 1991 12:08 AM

Oh…hmmmm….that could be a real problem huh? Do other DOS programs use the IAC that much? There is 1 Reply.

#3538From: Ethan WinerOct 17, 1991 7:19 AM

Mitchel, It only takes -one- program to screw you up. –Ethan