I have an old Macintosh SE (the one with the slotted grille in the front) that has been sitting in a closet for years which I would like to spruce up and get it working order. It is complete and did work when I got it in 1997, but the last time I tried it (about 10 years ago), the hard-drive was having some problems (I can’t recall specifically if it had the click-of-death or just trouble spinning up). If I’m not mistaken, it uses a typical IDE drive and there is no specific distinction between a Mac drive other than the file-system.
Can I just pop in a normal IDE drive or are there any gotchas to worry about such as the various size limits of PCs (for example, the 137GB BIOS limit)? Do the speed or manufacturer matter? The original came with a 20MB or 40MB drive, so is there a limit to what can be used? The Wikipedia page for it says that the drive is SCSI.
What can I do about the software (specifically System 7 that is installed)? If I cannot copy the contents of the existing drive, is there a way to reinstall the OS? As far as I know, Mac users never had the option to download or reinstall from CD like Windows users did/do. Would it be legal to find and download a copy of System 7 since the OS was always included with the hardware?