Osborne 1 blues...

Hi folks! I grabbed my first Osborne I today :) I powered it and it showed a crisp and vivid monitor :D I had a bunch of disks, but none of them worked (boot error). So I tried them elsewhere: they were all Double Density (so I have DD drives) but almost unreadable: the surface is dirty and covered with spots, may be fungi :( I dowloaded some IMD images and gave it a try... It booted with the Osborne logo and then the screen was slowly filled with junk, mainly "@". The Osborne stopped responding: I pressed the Reset button... Continuous beep on reboot, screen filled with random chars. I powered off, waited some minutes: no changes, no boot. Beep and screen junk, the floppy drives lights dance rhythmically :p I'll able to open it only the next week (the work table is full), but I'd like to figure out what's happened. Ram? Rom? Thanks!