Segment alignment. Not read alignment. Large model memory allocators would allocate memory on segment boundaries. This is more or less essential if you need to

Segment alignment. Not read alignment. Large model memory allocators would allocate memory on segment boundaries. This is more or less essential if you need to use more than 64K of memory in your program. An 8-bit paragraph size (rather than the 4 that were used) would've forced all segment allocations to 256-byte boundaries, so that's where the fragmentation issue comes from. Steve Morse (one of the designers of the chip) talks about the issue in page 16 of this: https://www.stevemorse.org/8086history/8086history.pdf https://www.stevemorse.org/8086history/8086history.pdf