Category: Geek

Una soluzione al problema del “Unauthorized network card” sui thinkpad recenti.
Grazie a Tisheng Chen (tishengchen@yahoo.com).

In recent IBM thinkpad systems, there is a limit to allowed MiniPCI wireless cards.
When an unauthorized card is plugged in, the system doesn’t boot and halt with an error message like:

ERROR
1802: Unauthorized network card is plugged in
Power off and remove the miniPCI network card.


I met this 1802 error problem several months ago, and since then my wifi card was used in a very clumsy and inconvenient way. I used to boot to LILO menu or Windows system first, then suspend and plug in the card. After that, when the system is awake, the card is working.

Recently, I learned two solutions to attack this problem. One is to crack the BIOS by modifying the PCI_ID list of allowed cards in the BIOS, as suggested by Paul Sladen and Matthew Garrett.
(Reference: http://www.paul.sladen.org/thinkpad-r31/wifi-card-pci-ids.html)

The other way is unbelievably simple. There is a byte in CMOS which controls whether an “unauthorized” card is allowed or not. That’s 0x6a, actually only the bit 0x80. The program to unlock the authorization mechanism is like (asm):

MOV DX,0070
MOV AL,6A
OUT DX,AL
MOV DX,0071
IN AL,DX
OR AL,80
OUT DX,AL
MOV AX,4C00
INT 21


The program can be downloaded from: http://jcnp.pku.edu.cn/~shadow/1802/no-1802.com
To use this program, you need to boot to DOS.

The CMOS solution is safe, but I’m not sure that it works for all recent thinkpads and all cards. The BIOS crack sure does, however it is difficult and dangerous.