Re: point to an address above 1M ?

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#2377

From: Steve Resnick
Date: Tue, 25 Sep 1990 22:10

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In article <609@demott.COM> kdq@demott.COM (Kevin D. Quitt) writes:
>In article <1990Sep24.204400.26052@Octopus.COM> stever@Octopus.COM (Steve Resnick ) writes:
>>In article <14016@hydra.gatech.EDU> gb7@prism.gatech.EDU (Joe Bradley) writes:
>>>
>>>Can someone tell me how to set a pointer (in MS C) to an address above
>>>1M? 
>
>>paging hardware on the video card. The FFFF:FFFF address is the top limit
>
>    Picking a nit, to be sure, but the highest address is *not* FFFF:FFFF,
>it is F000:FFFF (or FF00:0FFF, or FFF0:00FF, or FFFF:000F).

Well, sort of... FFFF:FFFF is the highest address a 32bit pointer will access
is it is used in the conventional DOS style addressing. If the A20 line is
enabled and there is an additional 62K above 1M the 0xFFFFFFFF pointer should
access the top of this RAM. You are, however, correct, Kevin, when you
say that F000:FFFF is the top limit for an 8086(8) and 80186(8) processors.

I love picking nits! :)

Cheers! 
Steve

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Message-ID: <1990Sep25.221057.4908@Octopus.COM>

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References: <1990Sep24.204400.26052@Octopus.COM> <609@demott.COM>

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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!sun-barr!apple!vsi1!octopus!stever
From: stever@Octopus.COM (Steve Resnick )
Newsgroups: comp.os.msdos.programmer
Subject: Re: point to an address above 1M ?
Message-ID: <1990Sep25.221057.4908@Octopus.COM>
Date: 25 Sep 90 22:10:57 GMT
References: <1990Sep24.204400.26052@Octopus.COM> <609@demott.COM>
Reply-To: stever@octopus.UUCP (Steve Resnick )
Distribution: usa
Organization: Octopus Enterprises, Cupertino CA
Lines: 28

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