Hot-insert PCMCIA cards / change MAC-ID on older Thinkpads?

I am wondering if the older PII / PIII Thinkpads, like the 600 and T20,
support hot-inserting of PCMCIA/PC-Cards (Orinoco 802.11 wifi card)?
Also, does the trick where you change the cards MAC-ID in the registry
and re-insert the card work with these laptops?

Thanks

On 11 Oct 2006 16:50:52 -0700, (E-Mail Removed) wrote in
<(E-Mail Removed) .com>:

>I am wondering if the older PII / PIII Thinkpads, like the 600 and T20,
>support hot-inserting of PCMCIA/PC-Cards (Orinoco 802.11 wifi card)?

They do.

>Also, does the trick where you change the cards MAC-ID in the registry
>and re-insert the card work with these laptops?

Probably depends on the specific card rather than the host computer.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
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Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

The correct terminology is "PC Card", not "PCMCIA Card".

In general, all devices that support PC Cards support hot insertion.
Also, in general (but less general), removal is ALMOST always supported,
although you are supposed to use the system tray icon to "stop" the card
before removing it. There are somewhat more issues with removal than
with insertion, however, and more still with insertion, removal and
RE-insertion. Some drivers (and the issue really is in the drivers) do
have problems with removal and/or re-insertion and will lock up the
system. But the PC Card specs and PC Card controllers (hardware in the
laptop) are universally intended to support hot insertion and then
"stopping/removing" the card. Unless the driver screws it up.

The MAC address of a network card is part of the card itself. Nothing
you can do in Windows (e.g. the registry, etc.) would normally be
capable of changing the MAC address. Some network interface chips do
have the ability to have their MAC addressed changed, but it's normally
done by running a utility that changes the MAC address in the card
itself (often by reprogramming flash memory on the card). There is an
assumption made in the design of the internet itself and how message and
packet routing work that a MAC address is unique in the entire world,
and if you violate this you may find that your device does really
strange things or even becomes entirely non-functional.

(E-Mail Removed) wrote:
> I am wondering if the older PII / PIII Thinkpads, like the 600 and T20,
> support hot-inserting of PCMCIA/PC-Cards (Orinoco 802.11 wifi card)?
> Also, does the trick where you change the cards MAC-ID in the registry
> and re-insert the card work with these laptops?
>
> Thanks
>

On Wed, 11 Oct 2006 20:57:20 -0400, Barry Watzman
<(E-Mail Removed)> wrote in <(E-Mail Removed)>:

>The correct terminology is "PC Card", not "PCMCIA Card".

-1 point for technical pedantry.

>In general, all devices that support PC Cards support hot insertion.

In theory, but not always in practice, older versions of Windoze being a
major case in point. -1 point for inaccuracy.

>Also, in general (but less general), removal is ALMOST always supported,
>although you are supposed to use the system tray icon to "stop" the card
>before removing it.

To be equally technical, that's "warm" removal, not "hot" removal.
-1 point for inaccuracy.

>There are somewhat more issues with removal than
>with insertion, however, and more still with insertion, removal and
>RE-insertion. Some drivers (and the issue really is in the drivers) do
>have problems with removal and/or re-insertion and will lock up the
>system. But the PC Card specs and PC Card controllers (hardware in the
>laptop) are universally intended to support hot insertion and then
>"stopping/removing" the card. Unless the driver screws it up.

Which is the point -- theory is of little comfort in the real world.

>The MAC address of a network card is part of the card itself.

Not in the case of a "soft" adapter, like most PC Cards, where much of
the functionality is in the host driver. -1 point for incompleteness.

>Nothing
>you can do in Windows (e.g. the registry, etc.) would normally be
>capable of changing the MAC address.

-1 point for inaccuracy. (If you're going to presume to lecture someone
else, you should be very careful to get your own facts right.)

See <http://www.klcconsulting.net/smac/>:

SMAC is a powerful, yet an easy-to-use and intuitive Windows MAC
Address Modifying Utility (MAC Address spoofing) which allows users
to change MAC address for almost any Network Interface Cards (NIC) on
the Windows 2000, XP, 2003, and VISTA Server systems, regardless of
whether the manufacturers allow this option or not.

SMAC does not change the hardware burned-in MAC addresses. SMAC
changes the "software based" MAC addresses, and the new MAC addresses
you change will sustain from reboots.

The Registry hack for some other versions of Windoze is at
<http://www.klcconsulting.net/Change_MAC_w98.htm>.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

(E-Mail Removed) wrote:
> I am wondering if the older PII / PIII Thinkpads, like the 600 and T20,
> support hot-inserting of PCMCIA/PC-Cards (Orinoco 802.11 wifi card)?
> Also, does the trick where you change the cards MAC-ID in the registry
> and re-insert the card work with these laptops?
>
> Thanks
>
Hi,
I used Orinoco Gold -11A/b/g card with T21, it's hot pluggable for sure.
MAC is like cast in stone. Embedded in the card(only one in the world)
I don't think you can play with it. I wonder why you want to change it?

John Navas wrote:

> >The MAC address of a network card is part of the card itself.
>
> Not in the case of a "soft" adapter, like most PC Cards, where much of
> the functionality is in the host driver. -1 point for incompleteness.

-50 points for being completely incorrect, and -50 further points plus
a ruler on the hand for your annoying pseudo-paedagogical style. I can
only assume you spent a lot of time around nuns.

While it is usually possible to change the MAC address temporarily or
permanently by poking card registers, the MAC address is part of the
card; it is generally in an external serial EEPROM and on powerup the
MAC [chip] reads it out of EEPROM into on-chip registers. (How else do
you think boot-from-LAN is supported?).

There are useful reasons why you might need to set a specific MAC
address from the host side - for example, some embedded applications
don't have the EEPROM, they use a global flash segment attached to the
main microcontroller to store all system configuration data - including
the MAC address. Hence all MAC chips that I've seen allow the host to
write the MAC address registers directly.

You can also write the EEPROM, if attached, through the MAC chip, and
thereby permanently change the MAC address of the device.

Perhaps you might want to consult the IEEE on the issue of how MAC
addresses are assigned to hardware.

Tony Hwang wrote:

> > Also, does the trick where you change the cards MAC-ID in the registry
> > and re-insert the card work with these laptops?
> I used Orinoco Gold -11A/b/g card with T21, it's hot pluggable for sure.
> MAC is like cast in stone. Embedded in the card(only one in the world)
> I don't think you can play with it. I wonder why you want to change it?

So he can connect to networks that are locked to specific MAC
addresses, and/or so he can run software that's nodelocked to a
specific MAC address.

On 12 Oct 2006 04:12:56 -0700, (E-Mail Removed) wrote in
<(E-Mail Removed) .com>:

>John Navas wrote:
>
>> >The MAC address of a network card is part of the card itself.
>>
>> Not in the case of a "soft" adapter, like most PC Cards, where much of
>> the functionality is in the host driver. -1 point for incompleteness.
>
>-50 points for being completely incorrect, and -50 further points plus
>a ruler on the hand for your annoying pseudo-paedagogical style. I can
>only assume you spent a lot of time around nuns.

+1 point for essentially confirming what I wrote.
-1 point for your own pseudo-pedagogical style.
-1 point for technical accuracy.
-1 point for guessing my religion.
-1 point for courtesy.
-1 point for sense of humor.

>While it is usually possible to change the MAC address temporarily or
>permanently by poking card registers, the MAC address is part of the
>card; it is generally in an external serial EEPROM and on powerup the
>MAC [chip] reads it out of EEPROM into on-chip registers. (How else do
>you think boot-from-LAN is supported?).

* MAC (Media Access Control) is a sublayer of the data link layer in the
OSI network model, not a "chip".

* The MAC address is typically stored in non-volatile memory internal
(not external) to the Wi-Fi PC Card.

* The host Wi-Fi driver typically provides the control logic for Wi-Fi
PC Card adapters.

* The feature is actually Wake on LAN (WOL), not "boot-from-LAN", and
must be supported by host hardware and firmware.

* Wi-Fi PC Cards alone don't support WOL -- there's no WOL hardware
interface, and the host computer would have to be running for the host
Wi-Fi driver to detect a Magic Packet (making waking moot).

* A Wi-Fi PCI-PC Card adapter (e.g., ORiNOCO 11b PCI Adapter) can
include a controller chip with the necessary WOL logic, and the PCI bus
(2.2 or later) provides the necessary hardware interface

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

I guess Windbag the Sailor deserves one more message...

ObWarning: I design-in this sort of hardware for a living (well, wired
Ethernet more than wireless, but at the host side it makes little
difference).

> * MAC (Media Access Control) is a sublayer of the data link layer in the
> OSI network model, not a "chip".

The physical part that implements the link layer is referred to as a
MAC [chip]. Go look at some datasheets for wired Ethernet parts. Some
MACs integrate the PHY and are referred to as MAC+PHY chips. Of course,
you'd know this if you had ever designed in one of these parts. The
division of labor is slightly different in an 802.11 implementation but
the idea is the same. However one doesn't as often hear someone talk
about a "wireless MAC chip" as about a [wired] "Ethernet MAC", I grant.
The phrase is used, though.

Go to <http://www.realtek.com.tw/>, Communications Network ICs,
Wireless LAN ICs, WLAN NIC, IEEE 802.11a/b/g, MAC/BBP. Wow. There you
see MAC (Media Access Control) chips and BBPs (Baseband Processors).

Another illustrative link:
<http://www.xilinx.com/products/silicon_solutions/fpgas/virtex/virtex4/capabilities/ethernetmac.htm>

Perhaps some elementary electronics courses might help you learn the
terminology. Etiquette courses wouldn't hurt either.

> * The MAC address is typically stored in non-volatile memory internal
> (not external) to the Wi-Fi PC Card.

Usually EEPROM, as I said. It is external to the MAC chip, generally
(though not universally). Yes, it is inside the WiFi card, though this
is irrelevant to the discussion. When I said external, I meant external
to the MAC.

> * The host Wi-Fi driver typically provides the control logic for Wi-Fi
> PC Card adapters.

You ought to look at the datasheets, it's all in there. Generally a
WiFi card contains a micro with a small bootloader only. The host
uploads the main bulk of the firmware to the card when the driver is
loaded, in such instances. Implementations vary; some devices have the
complete radio firmware in flash and hit the ground running as soon as
power is applied. But the realtime stuff is all run on the micro in the
card, in any case.

> * The feature is actually Wake on LAN (WOL), not "boot-from-LAN", and
> must be supported by host hardware and firmware.

You're not talking about the same thing. I'm talking about _booting_ an
appliance from the LAN, i.e. a diskless workstation. Of course you'd
know what I was talking about if you ever set up a network more complex
than plugging in a bit of 10baseT and opening Network Neighborhood.

> * Wi-Fi PC Cards alone don't support WOL -- there's no WOL hardware

Irrelevant.

John Navas <(E-Mail Removed)> hath wroth:

>-1 point for sense of humor.

The MAC address is stored in a protected portion of the NVRAM on the
wireless card. This section also contains the boostrap loader and
sometimes a TFTP server for making post production changes, especially
if the card is earmarked for use in a wireless router. Some PCMCIA
cards also include a JTAG port for companies that like to ship their
prototypes.

I'll ignore the steps in the boot process as they don't have much to
do with the original question.

When Windoze loads the wireless card driver, it reads the MAC address
from the card and stores it temporarily in the registry. This value
can be changed by various utilities and registry tweakers thus making
MAC spoofing possible. In some drivers, it can even be changed in the
Windoze device properties.

The current question revolves around whether Windoze re-reads the MAC
address from the PCMCIA card when hot swapping, or if it continues to
use the MAC address in the registry. From what little tinkering I've
done, it seems to follow the device driver logic. If the driver is
smart enough to know that a different card has been inserted, then the
MAC address will be read from the new card. If it's lazy and doesn't
check for a card swap, then it uses the old MAC address from the
registry.

In other words, it's not the hardware (i.e. older Thinkpad) but rather
the card driver. As I vaguely recall, the early Orinocco drivers were
not NDIS drivers and did some rather interesting things (such as
promiscuous mode support). Later Proxim drivers are NDIS 5.1 based,
which eliminates these interesting things, and fixed the card swap
"problem".

+1 point to me for explaining how it works.
--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558