Quote:Well, so far i made another experiment !
In order to force the Voodoo5 card to operate with 1.5 Volts ( AGP 4x ) i connect the AGP A2 pin to ground.
In this way, the Mobo should detect the card as a AGP4x card and supply it with 1.5Volts.
Unfortunately the system did not start ! ( Epox Post error message is 2d ) ... My Board Epox 8K5A2 did not have the possiblity to change the AGP Voltage in order to go over the 1.65 Volts...
What i expect with this ?
I was sure that with this both modification ( A2 grounded and AGP Voltage increasing ) the card will start in an Universal AGP Slot ( AGP1x,2x,4x ) and ...very important ... i can select the AGP4x in BIOS !
If this could be possible, then this will be for me a good evidence that the card can be pluged in a AGP4x/8x Slot without problems !
Fell free to comment my experiment !
P.S. Nor the voodoo card and Mobo were damaged ...
Nice try, Radu, but, do not get upset at me, nice but futile...
First, a statement that there is no doubt about its truth: it does not matter if you are able to select 4x or even 8x mode for AGP in BIOS. A Voodoo5 will allways default to PCI66 mode. It is just the way those cards were built.
Now... the state of the A2 pin is questioned almost only into AGP universal 2.0 slot powered mainboards. With very few exceptions, the 1.5V-only boards assume that only 1.5V/0.8V video cards could be inserted into the keyed slot and after all, have no possibility to provide 3.3V signaling if such a card would ever be fitted into so there is no point to check for a grounded A2 pin for AGP 8x motherboards.
With AGP universal 2.0 mainboards the TYPEDET value is examined at power-up and the video card do negociate with the motherboard's chipset for a common compatible signaling mode. In your special case, in this pre-boot sequence the 8k5a2 MB finds that a 1.5V video card in inserted (due to the state of the modded TYPEDET) and selects 1.5V signaling to use to comunicate to the GPU(s).
Allthough VSA100 is capable of this mode, on the Voodoo5 PCB it is hardwired for 3.3V only and the 1.5V signals sent by the MB are not able to cross the treshhold required by the GPU. Therefor the mainboard concludes that it is not able to "talk" to the video card and returns a 2Dh error code, as expected.
Again, friends, do not get confused about the AGP mode and the signaling value apparent link. A video card if built compatible, should be able to opperate correctly in AGP 2x mode with 1.5V signaling with no problem. the trouble is the other way: it should not be possible for a video card to run at AGP 4x or 8X mode with 3.3V signaling (ofcourse, we do not care about that since our Voodoo5 cards will default to PCI66 mode anyway, but I was just stating the facts).