If I just may be of some help in advance - THAT IS; before any who are waiting receive their A1s.
A point to note is that the internal expansion consists of TWO separate buses......
° The THREE PCI slots (togather) are for the usual 33Mhz PCI expansion cards. Both 3.3v and 3.3/5v cards can be used here.
° The FOURTH PCI slot (near to the AGP slot) is for 66Mhz 3.3v cards. This shares the bus common with the AGP slot. 5v cards
should NOT be inserted here although such can be physically inserted.
I'll leave it to someone else to go into more detail on this matter.
