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<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" colspan=2 height=50 BGCOLOR="#333366" TEXT="#080000"> <div> <B>block</B></div> <div> </div> </td> </tr><tr> <td valign="top" width=165 BGCOLOR="#CCCC99" TEXT="#080000"> <div> <B> <TABLE BORDER="0" CELLPADDING="2" CELLSPACING="1" WIDTH="132" BORDERCOLORLIGHT="#C0C0C0" BORDERCOLORDARK="#808080" FRAME="BOX" RULES="ALL" ALIGN="BOTTOM" HSPACE="0" VSPACE="0" > <tR> <tD VALIGN=TOP HEIGHT= 35 ><NOBR><div> <IMG BORDER="0" SRC="1x1.gif" HEIGHT="29" ALIGN="BOTTOM" HSPACE="0" VSPACE="0" WIDTH="21"></div> </NOBR></tD> <tD VALIGN=TOP><NOBR><div> <A HREF="id809.htm" TARGET="_top" TITLE="copy"><U><B><IMG SRC="004151d0.gif" border=0 width="21" height="29" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></U></A></div> </NOBR></tD> <tD VALIGN=TOP WIDTH="20"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="35" ALIGN="bottom" WIDTH="20" HSPACE="0" VSPACE="0"></tD> <tD VALIGN=TOP><NOBR><div> <A HREF="id797.htm" TARGET="_top" TITLE="block copy more next"><U><B><IMG SRC="0c80d1d0.gif" border=0 width="13" height="29" ALT="up" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></U></A></div> </NOBR></tD> <tD VALIGN=TOP><NOBR><div> <IMG BORDER="0" SRC="1x1.gif" HEIGHT="29" ALIGN="BOTTOM" HSPACE="0" VSPACE="0" WIDTH="27"></div> </NOBR></tD> </tR> </TABLE></B></div> <div> <A HREF="tanenbaum__1987__operating_systems.htm" TARGET="_top" TITLE="Operating Systems"><U><B>Tanenbaum [1987] Operating Systems</B></U></A></div> <bR> </td> <td valign="top" height=430 BGCOLOR="#FFFFFF" TEXT="#080000"> <div> <TABLE BORDER="2" CELLPADDING="2" CELLSPACING="1" WIDTH="477" BORDERCOLORLIGHT="#C0C0C0" BORDERCOLORDARK="#808080" FRAME="VOID" RULES="COLS" ALIGN="BOTTOM" HSPACE="0" VSPACE="0" > <tR> <tD VALIGN=TOP HEIGHT= 110 WIDTH="180"><div>      test cx,#0x8000</div> <div>      jnz L3</div> <div>      test dx,#0xFFFF</div> <div>      jnz L3</div> <div>      jmp L4</div> <div> L3:     mov cx,#0x8000</div> <div> L4:     mov ax,ax</div> </tD> <tD VALIGN=TOP><NOBR><div> if bytes >= 32768, only do 32768</div> <div> per iteration</div> <div> check high-order 17 bits to see if bytes</div> <div> if bytes >= 32768 then go to L3</div> <div> if bytes < 32768 then go to L4</div> <div> 0x8000 is unsigned 32768</div> <div> save actual count used in ax; needed later</div> </NOBR></tD> </tR> </TABLE></div> <bR> <div> <IMG SRC="295e1d90.gif" border=0 width="481" height="217" ALT="VISIO 5 Drawing" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> <bR> </td> </tr></table></body>