Register parameters
IN:
A = 0, always (see notes below)
BC = requested size of reserved memory in bytes (2 to 16384)
IX = memory handle (returned from OS_Mop)
OUT, if call successful:
Fc = 0
HL = address of memory allocated (H14 & H15 are memory mask)
B = bank number of allocated memory
C = segment specifier implied by HL (H14 & H15)
OUT, if call failed:
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
Registers changed after return:
....DE../IXIY same
AFBC..HL/.... different
Notes
Block allocation (more than one or 256 bytes) is implemented since OZ 4.7. Up to one bank can be requested (16384 bytes).
If such a block is requested (more than 256 bytes), MM_MUL has to be specified in OS_Mop.
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.
Normally memory is allocated from slots 1-2-3-0 in that order.
If MM_MUL is not specified in OS_Mop, all memory allocated from that pool is guaranteed to be in same bank. Additionally, memory area returned from OS_Mal is guaranteed to be in single page.
If MM_MUL is specified in OS_Mop, slot 1-3 can be forced during first OS_Mal by loading A with slot number.
Related calls
OS_Bix, Bind in extended address
OS_Box, restore bindings after OS_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
OZ_Mgb, get current bank binding in segment
OZ_Mpb, set new bank binding in segment