[comp.sys.zenith.z100] Allocating memory via Int 21h, Function 048h

leno@NUSC-NPT.NAVY.MIL ("LENO S.J.") (05/27/89)

Hi,
  I am working on a small machine language programand I
 want to allocate a chunk of memory for scratch work.
 I will need a 64k block. I have 768k so this should be
 no problem at all. I'm using Int 21h, function 48h.
 I am asking for 01000h 16 byte paragraphs. I'm told,
 by DOS, that the most it can give me is 3 paragraph or
 48 bytes. Something sounds fishy. Any ideas would be
 welcome. BTW, I am using MS-DOS 2.21 for the Z100. I
 do get the same problem when I run this part of the
 code on an IBM. If anyone wants to hazard a guess I
 can send a code fragment. 
      Thanx,
           Scott

ahd@CLUTX.CLARKSON.EDU (Drew Derbyshire) (05/27/89)

Scott,

If you wrote a com file, you alreafy own all of memory.  Address
of last address you can address wil be in the PSP, I can look it up if you
need it.

Drew