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From: bright@Data-IO.COM (Walter Bright)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Turbo C++ and Extended Memory, Huge model, large data structs
Keywords: Turbo C, Huge Extended Memory
Message-ID: <2708@dataio.Data-IO.COM>
Date: 12 Sep 90 18:49:56 GMT
References: <ajai.653069128@talos.sce.carleton.ca>
Organization: Data I/O Corporation; Redmond, WA
Lines: 24

In article <ajai.653069128@talos.sce.carleton.ca> ajai@sce.carleton.ca (Ajai Sehgal) writes:
<I'm writing an application in Turbo C++ which requires large data structures,
<ie an array of dimension 1,500,000 bytes (to hold a 512 x 512 image in real
<format). I thought I could use farmalloc to allocate a large chunk of memory
<and then use ponters to store and retrieve the data. The problem I encounter
<is the lack of memory access to memory above 640K. Can Turbo C++ make use of
<extended memory other than for overlay swapping? Is there a solution with
<Turbo C++ ? If not How about Zortec C++, I'm in early development so if I have
<to switch I will. Is Zortech better?

Zortech C++ supports the development of applications using the Rational
DOS Extender. This gives the program the capability to directly access up
to 16Mb of memory (it runs the program in 286 protected mode). You will
need to purchase the Rational DOS Extender in addition to the Zortech compiler
to do this. Call Zortech at 800-848-8408 for more info.

You still cannot declare or allocate a single object that consumes more than
64k, even in protected mode. For your application, I suggest instead
allocating 512 arrays of 512 bytes each, as in:
	char *array[512];
	for (i = 0; i < 512; i++)
		array[i] = (char *) malloc(512);

P.S. I wrote the compiler.