package storage /* See: "Beneath Apple DOS" https://fabiensanglard.net/fd_proxy/prince_of_persia/Beneath%20Apple%20DOS.pdf https://github.com/TomHarte/CLK/wiki/Apple-GCR-disk-encoding */ type diskette16sector struct { nib *fileNib position int } func (d *diskette16sector) PowerOn(cycle uint64) { // Not used } func (d *diskette16sector) PowerOff(_ uint64) { // Not used } func (d *diskette16sector) Read(quarterTrack int, cycle uint64) uint8 { track := d.nib.track[quarterTrack/4] value := track[d.position] d.position = (d.position + 1) % nibBytesPerTrack //fmt.Printf("%v, %v, %v, %x\n", 0, 0, d.position, uint8(value)) return value } func (d *diskette16sector) Write(quarterTrack int, value uint8, _ uint64) { track := quarterTrack / 4 d.nib.track[track][d.position] = value d.position = (d.position + 1) % nibBytesPerTrack }