BrokenThorn Entertainment

Posted: **Tue Dec 02, 2008 3:42 pm**

Hello!

First of all, thank you VERY much for writing these tutorials, they're helping me very well in learning the 'dark arts of OS development'. I found an error in tutorial in #9 when cross referencing my code, the code from brokenthorn and code from this site.

At "Method 3.1: Enabling A20 through keyboard controller" you post the following code:

Code: Select all

; Method 3.1: Enables A20 through keyboard controller
mov al, 0xdd	; command 0xdd: enable a20
out 0x64, al	; send command to controller

This should be

Code: Select all

; Method 3.1: Enables A20 through keyboard controller
mov al, 0xDF	; command 0xDF: enable a20
out 0x64, al	; send command to controller

I tested it with Bochs (version 2.3.7). Your code doesn't work, the code from the site I used did. Just letting you know!

Sorry for being a nitpicking bastard

.

Thank you very much for these tutorials!
- MadMax

edit: fixed some grammatical errors and typos

Posted: **Mon Dec 08, 2008 5:30 pm**

okay, I may have been a little quick to judge. It works in Bochs. But after some research I learned that some hardware developers implement the 0xDD instruction, others the 0xDF. Some both, some none. Sorry for being such an idiot...

Posted: **Mon Dec 08, 2008 6:12 pm**

Not a problem, if there is a problem you can always just ask us. We will be glad to take a look at the code or the problem if its on our behalf. but thanks for shareing=].

BrokenThorn Entertainment

Error in tutorial #9

Error in tutorial #9