User`s manual

See the LOAD ~ommal1d (pages

parameters device# and command#.

) for an explanation of the

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When you tell the disk drive to SAVE a program, the DOS must take

several steps. First, it looks at the directory to see if a program with that name

already exists. Next it ~he~ks to see that there is a directory entry available for

the name. Then it che~ks the BAMto see if there are enough blocks in which to

store the program. If everything is OK up to this point, the program is stored. If

not, the error light will flash.

SAVE and Replace

If a program already exists on the disk, it is often necessary to make a

~hange and re-SAVE it onto the disk. In this case, it would be inconvenient to

have to erase the old version of the program and then SAVEit.

If the first characters of the program name are the "(aP'sign followed by a

o and a colon (:), the DOS knows to replace any old program that has that name

with the program that is now in the computer's memory. The drive checks the

directory to find the old program, then it marks that entry as deleted, and it

next creates a new entry with' the same name. Finally, the program is stored

normally.

FORMAT FOR SAVE WITHREPLACE:

SAVE "=0:" + nameS, device#, command#

For example, if a file was called TEST, the SAVE and replace command

would be SAVE"(u,O:TESr,8.

The reason for the 0: is to keep compatibility with other Commodore disk

drive units which have more than one drive built in. In that case, the number 0

or 1is used to specify which drive is being used.

VERIFY

The VERIFY command works to check the program currently in memory

against the program on disk. You must include a device# with the VERIFY

command. The computer does a byte-by-byte comparison of the program,

including line links-which may be different for different memory configura-

tions. For instance, if a program was SAVEd to disk from a 5K VIC 20, and

re-LOADed on an 8K machine, it wouldn"t VERIFY properly because the links

point to different memory locations.

FORMAT FOR VERIFY COMMAND:

VERIFY name$, device#