;扇区结束标志是否正确？&nbsp
06B1&nbsp745A&nbspJZ&nbspREAD_SECTOR_SUCCEEDED&nbsp
;正确&nbsp
06B3&nbsp83EF05&nbspSUB&nbspDI,+05DI=DI-5&nbsp
06B6&nbsp7FDA&nbspJG&nbspREAD_SECTOR_LOOP

06B8&nbsp85F6&nbspTEST&nbspSI,SI&nbsp
06BA&nbsp7583&nbspJNZ&nbspDISPLAY_ERROR_MESSAGE_LOOP:&nbsp
;显示错误信息：缺少操作系统

06BC&nbspBE2E07&nbspMOV&nbspSI,072E&nbsp
06BF&nbspEB8A&nbspJMP&nbspDISPLAY_ERROR_MESSAGE_LOOP_ALIAS
;显示错误信息：加载操作系统时发生错误。

070D&nbspEB74&nbspJMP&nbspCONTINUE_KOAD_OS

0783&nbsp8BFC&nbspMOV&nbspDI,SP
;DI=7C00&nbsp
0785&nbsp1E&nbspPUSH&nbspDS
0786&nbsp57&nbspPUSH&nbspDI
0787&nbsp8BF5&nbspMOV&nbspSI,BP
0789&nbspCB&nbspRETF转到执行0000:7C00处的语句，即操作系统的引导程序