I'm a little late on this thread .. it's hard to keep up. Besides the Tech Ref manuals and the Hardware maintenance manuals, the Sams ComputerFacts have also been helpful. I'm a big PCjr fanatic, but I find the hardware literature from the PC, XT and AT to be helpful because it is all very closely related. Besides keeping the old classic cards, I look for (and hold) good general purpose cards. Future Domain 85x series SCSI cards are a good example; they work in eight bit systems like the PC and the software is functional enough to drive hard disks, CD-ROMs, etc. While we're on the topic, I've been trying to find an XT tech ref. I want it for the BIOS listing of the hard drive adapter. This kind of thing is useful when grafting one of the old MFM controllers onto a PCjr. Does anybody have a source for these? (I have the Jr tech ref and an AT tech ref, but finding an XT tech ref has been difficult.) Mike mbbrutman at brutman.com