That's right. The HP ScanJet 4c's SCL (Scanner Control Language) command set includes an unofficial PLAY TUNE command. I stumbled across this after reading an article on the ScanJet 4c in the feb. 1997 issue of HP Journal (see the sidebar Sing to Me).
The PLAY TUNE command basically varies the stepping rate of the scanner motor to produce audible frequencies. All it needs is a series of note frequencies and durations previously written to its SCSI buffer. The ScanJetPlay utility resulted from my efforts in trying out this easter egg. Check dis shit out, babee! :^)
ScanJetPlay requires libsane and libsanei (for SCSI access) from the SANE backends package. Note that libsanei and its header files is not installed per default, and must be done manually.
This just sounds so cool ... :)
Thats amusing... but nothing new actually. The old Commodore 64 had a program called "1541 music" that did essentially the same thing - slammed the read/write head mechanism of the 1541 floppy drive against the stop at different speeds. Was MURDER on the heads(the 1541 was notorious for going out of alignment and this certainly did nothing to help!) But it was mildly entertaining for a few seconds; a "WTF! Ha ha!" moment - until you realized what it was doing to your head alignment! LOL!