dna@dsd.UUCP (11/28/83)
I would like to respond to:
BTL-IH (fortune!hpda!hplabs!sri-unix!cca!decvax!harpo!floyd!clyde!ihnp4!
ihlpf!dap1)
In your question about allocating blocks of memory, DOS 2.0 allocates
ALL of user memory when a program is run. This is true for .EXE files
as well as .COM files. I had the same problem when running under
AZTEC C86. What I had to do is patch the startup assembly code. If you
do not have this code, you can figure out the top of your block quite
easily. It is DS:FFFF. Depending on what your startup code did, the
ES:0 points to the beginning of your block (It should also point to the
program prefix unless changed). I have no idea how you would attempt
to do this in a higher level language. I did all my changes in assembly
after using DEBUG on a program and Unassembling the startup code to make
sure it matched the distributed run-time package.
I'll say this much for Aztec-c. It may have bugs in the run-time
package (I have found four or five and fixed them all), but at least they
give you the source so you *CAN* fix it. If you have any questions, feel
free to try to get ahold of me some how. I don't even know if this message
will even get to you. If it does, the nice person who sends it to you
should be able to get a response to me.
Anyway, if you do not have access to the ES register, then if I may be
so bold to ask, what do you want with the ALLOCATE-BLOCK call? The only
way you could access at chunk of memory is to place the paragraph address
returned in the AX register into the ES register then reference your offset
from there. This is how 32 bit pointers work in PLM-86..
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Mike Spann