After some hard work I was able to remove the old PSU from the Performa 6300CD and install an ATX type PSU that fit into the same space. I used the cable harness from the old PSU to make an adapter for the ATX style connector. Anyway this allowed me to somehow fit an OrangePC 620 card (upgraded with a k6-2 400mhz + 128mb of ram) and be within the power budget.

Everything appears to work, however I can't seem to get windows 98 installed...I am running into an issue where my windows 98 CD reads fine on the mac side but wont read and throws an error ( "not ready reading") in the w98 boot disk DOS .

Does anyone have a link for the "Easy Install for Windows 98" CD that was included with the OrangePCI 620 / OrangePCI 3.4.2 or knew how a good way to install windows 98 SE on this from scratch? Also the CD-ROM MSCDEX does appear to load but doesn't seem to actually do anything positive in terms of allowing access to the CD-ROM from DOS. Very strange. Also maybe it's not loading the right CDROM driver by default? My 6300CD has a Sony CDU75S-25 SCSI cd drive. Not sure what I should use.