Editing Killer poke (section)

===Commodore 1541 Disk Drive===
The [[Commodore 64]] had an optional external 5-1/4" floppy drive. The [[Commodore 1541]] contained a 6502 microprocessor which was used to run [[Commodore DOS]] and also to manage the drive mechanism. The drives stored data on 35 tracks (#0–34), and the stepper motor could be manually controlled through BASIC by PRINT#-ing "MEMORY-WRITE" commands to the drive (which correspond to the POKE command of BASIC, but write to the drive's internal memory and I/O registers, not those of the computer itself). If the drive was at either end of its range (track 0 or track 39) and it was commanded to continue moving, there was no software or firmware method to prevent drive damage. Continued "knocking" of the drive head against the stop would throw the mechanism out of alignment. The problem was exacerbated by [[copy protection]] techniques that used non-standard disk formats with unusual track counts. The [[Commodore 1571]] had an optical head stop instead of a mechanical one.