On 8086, the assembler managed the segmentation. All you had to do was load the DS (and possibly ES) register with an assembler defined symbol at the beginning

On 8086, the assembler managed the segmentation. All you had to do was load the DS (and possibly ES) register with an assembler defined symbol at the beginning of your function. I never worked with the 80286, I pivoted to the i960 around 1992.