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Index > OS Construction > IBM/MS INT 13 Extensions - INSTALLATION CHECK version 1.2??

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LocoDelAssembly
Your code has a bug


Joined: 06 May 2005
Posts: 4633
Location: Argentina
LocoDelAssembly
I just tested a little boot code program to check which version of IBM/MS INT 13 Extensions have my old computer (a Cyrix 586). Ralf brown interrupt list provides the following values to determinate the version:
Ralf Brown wrote:
AH = major version of extensions
01h = 1.x
20h = 2.0 / EDD-1.0
21h = 2.1 / EDD-1.1
30h = EDD-3.0
The problem is that the BIOS does not set the carry flag and change BX to AA55h so it means that the BIOS reports that the extentions are installed but in AH the value is 02h :S

Should I consider 02h as version 1.2 or it's a BIOS bug? My boot code reports version 0.2 because I do special processing with 01h only.

[edit] I forgot to say, I tested the same boot code on my new computer and it reports version 3.0[/edit]

[edit2] I repleased the attachment with a new boot code that provides more info (it show which set of functions are supported).

On my athlon64 says that "Extended disk access functions (AH=42h-44h,47h,48h)" and "Enhanced disk drive (EDD) functions (AH=48h,AH=4Eh)" are supported but in my 586 only EDD is supported. It seems to be true because the code below doesn't work on the 586 while in the athlon64 does
Code:
; Should be executed under a debugger
org 100h

      mov ah, 42h
      mov dl, 80h
      mov si, packet
      push  ds
      pop   [seg]
      int 13h
      int3

packet:

db 10h
db 0
dw 1
dw 7c00h
seg dw 0
dq 0    


[/edit2]

[/edit3] Improved source code readability...[/edit3]


Description:
Download
Filename: Boot.zip
Filesize: 1.68 KB
Downloaded: 46 Time(s)

Post 16 Mar 2006, 21:19
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LocoDelAssembly
Your code has a bug


Joined: 06 May 2005
Posts: 4633
Location: Argentina
LocoDelAssembly
no one knows how to get which version of the extentions I have? :'(
Post 17 Mar 2006, 16:56
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Dex4u



Joined: 08 Feb 2005
Posts: 1601
Location: web
Dex4u
I came across some code, but can not remember where Sad.
It could have been on this site: http://www.geocities.com/thestarman3/asm/mbr/MBR_in_detail.htm
Not sure though, No time to search
Post 17 Mar 2006, 19:54
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LocoDelAssembly
Your code has a bug


Joined: 06 May 2005
Posts: 4633
Location: Argentina
LocoDelAssembly
I can't find how to interpret 02h version but I found http://www.geocities.com/thestarman3/asm/debug/ATAscript.htm which is very usefull for something I'm trying to do with Int 13h

Thanks for the link!!!
Post 17 Mar 2006, 23:38
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