Disk 1: Sub CPU Data (0475slvl.pgm)
1. Turn off the A5000's power.
2. Insert the floppy disk containing the sub CPU data (file name: 0475slvl.pgm) into the A5000's disk drive and then turn the power on.
3. Press the DISK Mode button to display the [ DISK-PgmLoad ] screen.
4. Press the COMMAND/EXIT button to display the [ DISK Command Select ]screen.
5. Turn Knob 4 to the right to highlight the second line of the LCD [BACKUP, CD-DA, LOAD-OS ]. Then press Knob 4 to display the [ Command LOAD OS ] screen.
6. If the floppy disk drive is not selected, turn Knob 4 to select it. Turn  Knob 3 to display [ sub ] for the [ OS file type ] and then push Knob 1.
7. The message [ Load OS? Are you sure? ] will appear on the screen. Press  Knob 5 [ Yes ] to start loading from the floppy disk. Loading will take  approximately one minute.
8. The message [ Load OK. Upgrade OS? Are you sure? ] will appear on the  screen. Press Knob 5 [ Yes ] to start overwriting the program. Overwriting  will take approximately 5 seconds. DO NOT turn off the A5000's power during  this time. When all six of the red LEDs, F1 to F6, on the upper right of the 
unit light up, overwriting is completed. Turn off the A5000's power and eject the floppy disk.
9. Turn on the A5000's power while pressing the EDIT, REC and DISK buttons  simultaneously. During startup, the LCD will display [ A4000 ], but this is  normal. If this display does not appear, turn off the power and repeat this 
step.

Disk 2: Main CPU Data (0475mstl.pgm)
10. Insert the floppy disk containing the main CPU data (file name:  0475mstl.pgm) into the A5000's disk drive and then turn the power on.
11. Press the DISK Mode button to display the [ DISK-PgmLoad ] screen.
12. Press the COMMAND/EXIT button to display the [ DISK Command Select ]  screen.
13. Turn Knob 4 to the right to highlight the second line of the LCD [BACKUP, CD-DA, LOAD-OS ].
14. Press Knob 4 to display the [ Command LOAD OS ] screen.
15. If the floppy disk drive is not selected, turn Knob 4 to select it. Turn  Knob 3 to display [ main ] for the [ OS file type ] and then push Knob 1.
16. The message [ Load OS? Are you sure? ] will appear on the screen. Press  Knob 5 [ Yes ] to start loading from the floppy disk. Loading will take  approximately 3 minutes.
17. The message [ Load OK. Upgrade OS? Are you sure? ] will appear on the screen. Press Knob 5 [ Yes ] (NOT Knob 1!) to start overwriting the A5000's internal  operating system. Rewriting will take approximately 25 seconds. DO NOT turn off the A5000's power during this time. The red LEDs, F1 to F6, on the upper right of the unit will light up in order. When all six lights have illuminated,  overwriting is completed. Turn off the A5000's power and eject the floppy disk.
18. To return the unit to its factory settings, turn on the power while  pressing the F1 and the ASSIGNABLE buttons. [ FACTORY SET! ] will appear  briefly in small letters at the upper left of the LCD followed by [ A5000 ]. You can then let go of the buttons.
19. To confirm that the program been successfully updated, go through steps 11 to 14 and check the version displayed on the screen. 

This concludes this procedure.