motherboard w/o 3.3V PCI fingers

hi there,

i have been working on a PCI 5V DAQ card. there is a surprising fact that i have observed regarding the motherboard on which i am mounting the card. it is an old pentium-I 200MHz board containing both PCI and ISA slots (one of those legacy boards). when i mounted the card and checked power supplies, i found that 3.3V supply is simply not there. the PCI spex v2.2 defines 3.3V power supply fingers on the bus. hence i routed my board accordingly (it contains Spartan2 and platform flash mem which require 3.3V for Vcco).

is this a generic case or what? has anybody seen/worked on such boards? doesnt this board violate PCI standards?

now i will have to change the board. can anyone tell me what i should look for on the motherboard to ensure that it has both types of power supplies supported?

TIA, Shreyas

Reply to
Shreyas Kulkarni
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Shreyas Kulkarni schrieb:


I had the same problem with an older ASUS P2L97-S, i think with older pci specification the 3.3 V were optional. my board also had an AGP connector beside the PCI slots with 3.3V and I had to make a wiring between the AGP and the PCI Slots.

I think all newer board are according to the PCI spex v2.2 and have the

3.3V at the PCI connectors
Reply to
Thomas Fischer

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