Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!wuarchive!rex!samsung!sdd.hp.com!ucsd!ucbvax!van-bc!rsoft!mindlink!a35
From: a35@mindlink.UUCP (Bruce Atherton)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Virtual Memory for the Heap
Message-ID: <2699@mindlink.UUCP>
Date: 2 Aug 90 16:03:42 GMT
Organization: MIND LINK! - British Columbia, Canada
Lines: 30

bright@Data-IO.COM (Walter Bright) writes:
> 
> I've used _handles quite a bit in my code. The reason they were implemented
> is that the code looked so *ugly* when explicit function calls had to be
> done to dereference a handle. Thus, making a handle a special pointer type,
> and having the compiler call the function for you, cleaned up the code
> a lot. I'd say that the _handles are certainly the easiest to convert your
> code into using.
> 
> The thing to watch out for is inadvertently converting a handle to a far
> pointer, as in stuff like:
>         char _handle *h;
>         h = (char *) handle_malloc(10);         /* error!       */
>         h = (char _handle *) handle_malloc(10); /* correct way  */

I agree that explicit calls for dereferencing is no way to implement
virtual memory.  Zortech seems to use the most elegant solution I've
heard about so far.

Can you use a _handle anywhere you would use a pointer?  Can you declare
a _handle to a _handle to a function that returns a _handle? Does this
have to be a part of the compiler, or could I write an object in any C++
that would do the same thing?

Finally, can you create a pointer into the ROM BIOS area?

Thanks for your help.

Bruce_Atherton@mindlink.UUCP or| Wham bam bam bam bam bam thank you Hymie.
uunet!van-bc!rsoft!mindlink!a35| We drive chicks MAAADD! - The Frantics.