Changeset 535 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm

Timestamp:

Apr 8, 2013, 5:09:44 PM (11 years ago)

Author:

aitotat@…

google:author:

aitotat@gmail.com

Message:

Changes to XTIDE Universal BIOS:

• AH=48h now returns Device Parameter Table Extension when RETURN_DPTE_ON_AH48H is defined.
• Removed few unnecessary instructions from hardware interrupt handler.
• P-Cylinders returned by AH=48h are no longer calculated from L-CHS capacity.

File:

• trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm (modified) (2 diffs)

trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm

@@ -120 +120 @@
     mov     [di+DPT.bPchsSectorsPerTrack], bh
 
+; This is what Award BIOS from 1997 Pentium motherboard does. I can't think
+; of any good reason to do the same but let's keep this here just in case,
+; at least for a while.
+%if 0
 %ifdef RESERVE_DIAGNOSTIC_CYLINDER
     ; Do not store P-Cylinders, instead calculate it from L-CHS total sector count.
@@ -130 +134 @@
     div     bx                          ; AX = Calculated cylinders
 %endif ; RESERVE_DIAGNOSTIC_CYLINDER
+%endif ; 0
 
     mov     [di+DPT.wPchsCylinders], ax