How do I know if the cardbus slots on an old laptop are 3.3V or 5V slots? The specs shown online generally just tell if the slot is type II or type III but don't tell the voltage.
The slots and cards are keyed, so a 3.3v Cardbus card should not be able to fit into a 5v only PCMCIA slot. Usually Cardbus is only present on Pentium MMX laptops and later, but like you say it's often not shown on the laptop itself.
Cardbus was a pretty massive jump in spec (ISA > PCI) so it's usually stated quite clearly in the specifications of any laptop that has it.
Thermalwrong wrote on 2020-10-10, 12:59:The slots and cards are keyed, so a 3.3v Cardbus card should not be able to fit into a 5v only PCMCIA slot. Usually Cardbus is only present on Pentium MMX laptops and later, but like you say it's often not shown on the laptop itself.
Cardbus was a pretty massive jump in spec (ISA > PCI) so it's usually stated quite clearly in the specifications of any laptop that has it.
I figured that out about not fitting, but I would like to know before getting the card if it will work with a laptop or not instead of buying a card and only then realizing that I can't put it in the slot.
Baoran wrote on 2020-10-10, 13:55:Thermalwrong wrote on 2020-10-10, 12:59:The slots and cards are keyed, so a 3.3v Cardbus card should not be able to fit into a 5v only PCMCIA slot. Usually Cardbus is only present on Pentium MMX laptops and later, but like you say it's often not shown on the laptop itself.
Cardbus was a pretty massive jump in spec (ISA > PCI) so it's usually stated quite clearly in the specifications of any laptop that has it.
I figured that out about not fitting, but I would like to know before getting the card if it will work with a laptop or not instead of buying a card and only then realizing that I can't put it in the slot.
Firstly get terminology straight:
PC-Card: anything about that size you can stick into a (mobile) PC
PCMCIA: basically 16b ISA bus, 5V
Cardbus: basically 32b PCI bus, 3.3V
How to recognize if seller doesn't sound like he knows the difference:
That copper grounding strip is a dead giveaway for Cardbus.
If the description is accurate (which admittedly is bold assumption on used computer sales, and still risky on original documentation), "PCMCIA" means a 5V only slot that is ISA-like, "CardBus" means a 3.3V slot that is PCI-like. All CardBus slots I know can fall back to 5V ISA mode. For cards, CardBus card have tend to have a gold-colored shield at the connector, whereas PCMCIA cards have an unshielded plastic connector.
If you already have the laptop at hand, you can also check what driver is in use for your PCMCIA or CardBus controller. Or you can use a flashlight to check the connector keying in the slot.
The seller basically says it is a 3.3V cardbus card and also says in description that because it is 3.3V it won't work in all pentium 2 or earlier laptops. Mainly I am trying to figure out if it works in some of those or if all Pentium 3 laptops have the 3.3V slots and if there is a way to figure it out by looking at the slot in the laptop. I know the differences in cards themselves, but I am trying figure out the differences in laptops themselves.
Baoran wrote on 2020-10-10, 15:51:The seller basically says it is a 3.3V cardbus card and also says in description that because it is 3.3V it won't work in all pentium 2 or earlier laptops. Mainly I am trying to figure out if it works in some of those or if all Pentium 3 laptops have the 3.3V slots and if there is a way to figure it out by looking at the slot in the laptop. I know the differences in cards themselves, but I am trying figure out the differences in laptops themselves.
That's probably something to look up in the specs of the laptop. It depends on the bridge chip used.
Baoran wrote on 2020-10-10, 15:51:Mainly I am trying to figure out if it works in some of those or if all Pentium 3 laptops have the 3.3V slots and if there is a way to figure it out by looking at the slot in the laptop.
Have a look at this image on wikimedia commons comparing the keying of a 3.3V cardbus and a 5V PCMCIA card. You will notice the wider key on the 3.3V card. If you manage to get good lighting and vision into the PC Card slot, you can check the receptacle for the size of the notch where that key needs to fit in.
mkarcher wrote on 2020-10-10, 14:57:All CardBus slots I know can fall back to 5V ISA mode.
No, the 5V only 16-bit PC Cards support it's optional.
Looks like the only way to detect is "plug and pray". 😀
Asus P4P800 SE/Pentium4 3.2E/2 Gb DDR400B,
Radeon HD3850 Agp (Sapphire), Catalyst 14.4 (XpProSp3).
Voodoo2 12 MB SLI, Win2k drivers 1.02.00 (XpProSp3).
Gamecollector wrote on 2020-10-10, 23:55:mkarcher wrote on 2020-10-10, 14:57:All CardBus slots I know can fall back to 5V ISA mode.
No, the 5V only 16-bit PC Cards support it's optional.
Looks like the only way to detect is "plug and pray". 😀
If what Dionb said earlier is true it would mean that if the laptop specs say word "cardbus" it would mean automatically that it is 3.3V slot, right? That is if I understood correctly that there isn't 5V cardbus cards and it would just say PCMCIA without cardbus if it was a 5V slot.
Baoran wrote on 2020-10-11, 01:35:Gamecollector wrote on 2020-10-10, 23:55:mkarcher wrote on 2020-10-10, 14:57:All CardBus slots I know can fall back to 5V ISA mode.
No, the 5V only 16-bit PC Cards support it's optional.
Looks like the only way to detect is "plug and pray". 😀If what Dionb said earlier is true it would mean that if the laptop specs say word "cardbus" it would mean automatically that it is 3.3V slot, right? That is if I understood correctly that there isn't 5V cardbus cards and it would just say PCMCIA without cardbus if it was a 5V slot.
Cardbus IS PCMCIA. It’s just a later PCMCIA standard that ran on 3.3v, is 32 bits and speaks PCI underneath. Cardbus slots can run on both 3.3v and 5v for backwards compatibility.
