The database is the same size in memory that it is on the disk, I think. Or at least only a small factor bigger. According to me six years ago, the Mark 1's cache size is 2.5MB, so your 1.5MB database shouldn't actually be a problem. Umm, 1MB left for caching, say 200kbits/s, 25Kbytes/s, that's 40 seconds. That won't be enough to ever spin the disk down, but it shouldn't be so little that it can't play at all.

Of course, it's not much use not being able to spin the disk down; that's just a recipe for drive failure when used in an actual car. Really for a collection that size you should be thinking about a Mark 2 or 2a.

Peter