INT 15,F - Format Periodic Interrupt (PS/2 only)

AH = 0F

AL = phase code

= 00 reserved

= 01 surface analysis

= 02 formatting

on return:

CF = 0 continue formatting/scanning

= 1 end of format/scanning

- after formatting/scanning each cylinder the formatting

routine calls this interrupt

- may be used by a program to gain control after formatting

a cylinder

- if invoked from a non-PS/2 CF=1 and AH contains the following

AH = 80h for PC and PCjr

= 86h on most other machines