Changeset 606 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h

Timestamp:

May 15, 2021, 8:27:11 PM (4 years ago)

Author:

Krister Nordvall

Message:

Changes:

• RESERVE_DIAGNOSTIC_CYLINDER has been completely removed as it wasted hard drive space, caused a compatibility problem with 32-bit disk access drivers under Windows 3.x and most importantly, it was in fact not needed since the same thing can be accomplished using the "User specified CHS" feature in XTIDECFG which is better because that applies only to that specific drive instead of all drives under XUB control.
• In BIOS builds containing MODULE_EBIOS (i.e. all official builds except the Tiny build), drives with a cylinder count less than or equal to 1024 had CHS translation applied to them unnecessarily if CHS translation method was set to Auto (which is the default). This bug has been present for a long time and, as a side effect, made RESERVE_DIAGNOSTIC_CYLINDER useless since the idea behind that was to provide compatibility with other old BIOSes using NORMAL addressing mode. WARNING! With this bug now being fixed, upgrading to this revision of the BIOS will require repartitioning and reformatting any drives affected by this (BIOSDRVS.COM can be helpful in determining which drives are affected).

File:

• trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH8h_HParams.asm (modified) (2 diffs)

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH8h_HParams.asm

@@ -61 +61 @@
 
     mov     [bp+IDEPACK.intpack+INTPACK.bl], bl
-
     mov     [bp+IDEPACK.intpack+INTPACK.es], es
     mov     [bp+IDEPACK.intpack+INTPACK.di], di
@@ -150 +149 @@
 ;--------------------------------------------------------------------
 AH8h_LimitAXtoMaximumLCylinders:
-%ifdef RESERVE_DIAGNOSTIC_CYLINDER
-    dec     ax
-%endif
     MIN_U   ax, MAX_LCHS_CYLINDERS
     ret