Commodore PC - FCB unavailable; Invalid disk change error; Lock violation error; Non-DOS disk error

268 MS-DOS User's Reference
U
F FCB unavailable
General failure error
■ An unusual error has occurred. This error usually requires an k^J
experienced programmer to fix it.
Choose R (for Retry) or A (for Abort).
I Invalid disk change error ^-^
■ You changed the disk in a drive when you weren't sup
posed to. , .
Put the disk back in the drive and choose R (for Retry). v_x
L Lock violation error
■ A program tried to access part of a file that another program \^j
was using.
Choose A (for Abort), or wait awhile and choose R (for Retry).
N No paper error ^—'
■ The printer is either out of paper or not turned on.
Non-DOS disk error K^J
■ ms-dos does not recognize the disk format because the disk is
missing information or contains another operating system.
Try running the chkdsk command to correct the problem. [^J
(See Chapter 3, "ms-dos Commands," for information about
chkdsk.) If running chkdsk does not solve the problem, you
should reformat the disk by using the format command — even i \
though this will destroy all the files on the disk. ^—^
Not ready error
■ The device (usually a drive or printer) specified in the error \^J
message is not ready to accept or transmit data
This often happens when the disk drive door is open. If this is
the problem, close the door and choose R (for Retry), or check {^J
to see if the printer is on and ready.
R Read fault error ^
■ msdos is unable to read data from the device (usually a disk ^-^
drive).
Check to see that the disk is properly inserted in the drive,
then choose R (for Retry). \^J
S Sector not found error
■ This error usually means the disk has a defective spot so that ( j
ms-dos cannot find the requested information on it. ^~^^
You should copy all files from the disk onto a good disk and
then try to reformat the defective disk. , \