OS_Mal, allocate memory

RST 20H, DEFB $54

IN:

     A = 0, always
     BC = requested size of reserved memory in bytes (2 to 256)
     IX = memory handle (returned from OS_Mop)

     Fc = 0
     HL = address of memory allocated (H14 & H15 are memory are memory
     mask)
     B = bank number of allocated memory
     C = segment specifier implied by HL (H14 & H15)

     Fc = 1
     A = error code:
          RC_HAND ($08), IX is not a valid memory handle
          RC_ROOM ($07), no room to allocate block in MEMORY POOL
          RC_ERR ($0F), if BC > 256 bytes, fatal error

     ....DE../IXIY same
     AFBC..HL/.... different

Remember "No Room" means the pool is exhausted, and not the whole of memory. If a subsequent OS_Mop cannot allocate a pool, then memory is definitively exhausted.

The call WILL NOT automatically bind in the allocated memory into the Z80 address space.

Related calls:

OS_Bix, Bind in extended address
OS_Box, restore bindings afterOS_BIX
OS_Fc, select fast code (fast bank switching)
OS_Mcl, close memory (free memory pool)
OS_Mfr, free (previously allocated block) memory
OS_Mgb, get current bank binding in segment
OS_Mop, open memory (allocate memory pool)
OS_Mpb, set new bank binding in segment