Changeset 547 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h

Timestamp:

Apr 21, 2013, 3:47:11 PM (12 years ago)

Author:

aitotat@…

google:author:

aitotat@gmail.com

Message:

Changes to XTIDE Universal BIOS:

• Hotkeys were incorrectly initialized to use 'C' as first hard drive letter.
• All CHS translate modes should again work (incorrectly decremented DX instead of DL, it might or might not have caused problems).

Location:

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h

Files:

• AH15h_HSize.asm (modified) (1 diff)
• Tools/Prepare.asm (modified) (3 diffs)

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH15h_HSize.asm

@@ -23 +23 @@
 ;--------------------------------------------------------------------
 ; Int 13h function AH=15h, Read Disk Drive Size.
+;
+; It is unclear what is the total number of sectors to return.
+; Award BIOS from 1997 returns full capacity instead of L-CHS limit
+; like we do. I think it makes more sense if this function returns
+; L-CHS limit.
 ;
 ; AH15h_HandlerForReadDiskDriveSize

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/Tools/Prepare.asm

@@ -45 +45 @@
 
     ; Make sure that sector count is valid
+    mov     al, [es:si+DAP.wSectorCount]
+    test    al, al
+    jz      SHORT ZeroSectorsRequestedSoNoErrors
+    js      SHORT InvalidNumberOfSectorsRequested
+
+%if 0   ; Slow version in the unlikely case that high byte needs to be checked.
     mov     ax, [es:si+DAP.wSectorCount]
     test    ax, ax
@@ -50 +56 @@
     cmp     ax, BYTE 127
     ja      SHORT InvalidNumberOfSectorsRequested
+%endif
 
     ; Get EBIOS command index to BX
@@ -55 +62 @@
     call    Prepare_GetOldInt13hCommandIndexToBX
     mov     al, [di+DPT.bFlagsLow]
-    eSHL_IM al, 1                   ; Set CF if LBA48 supported
+    shl     al, 1                   ; Set CF if LBA48 supported
     adc     bl, bh                  ; LBA48 EXT commands
     ret