Commodore 1541-II User Manual page 7

Chapter 7: Direct Access Commands 65
A tool for advanced users ... 65
Diskette organization 65
Opening a data channel 65
Block-Read 66
Block-Write 67
The original commands 68
The buffer pointer . 69
Allocating blocks 70
Freeing blocks 71
Using random files (advanced) 72
Chapter 8: Internal Disk Commands 73
1541 Memory Map 73
Memory Read .. 74
Memory Write 75
Memory Execute 77
Block Execute 77
User commands 78
Chapter 9: Machine Language Programs 80
Disk-related kernafl subroutines 80
Appendices
A. Changing the Device Number 81
B. Error Messages 83
C. Diskette Formats 87
D. Disk Command Quick Reference Chart 92
E. Test/Demo Diskette '. 93
List of Figures
1. Front Panel 5
2. Back Panel 6
3. Floppy Disk Hookup 8
4. Position for Diskette Insertion 12