God meant any and all beige Macs to run an OS prior to X. In the case of the beige G3, this providentially simplifies finding RAM for the thing, as finding 128MB or 256MB DIMMs physically small enough to fit in a G3 desktop is hard — they have to be low-profile in order to be able to close down and lock the drive shelf, and get the plastic top back on. So three 64MB DIMMs are fine, given that the thing will run MacOS 8.6 or 9.2 very well with that much RAM. God's ways are wonderful.