Memory Management Functions

 48H (BX=ffffH) determine largest available block
 48H   allocate a block of memory
 49H   free an allocated block of memory
 4aH   resize (shrink/expand) a memory block

 5800H query allocation strategy       5801H set allocation strategy
 5802H query upper-memory link         5803H set upper-memory link
 3306H See if DOS is in the HMA^       INT 2fH 4axxH Suballocate in the HMA

 XMS Services XMS memory/HMA control   EMM Services LIM-EMS memory
 DPMI Services DOS Protected Mode Interface services

 Accessing Upper Memory  how to allocate a UMB^
 Program Startup & Exit  memory considerations when a program starts
 CONFIG.SYS Commands     (DOS=, DEVICEHIGH=, etc. affect memory)

 MCB Memory Control Block layout    PSP fields wNextSeg, et al. are relevant
 INT 12H total conventional memory  INT 15H 88H total extended memory
 TSR/Popup Functions                         Service Groups   DOS Functions