184. Master ADFS compacting routine
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If you try a *MAP command after *COMPACT, you will often find that only
partial compaction has taken place. If fuller compaction is required, you
have to try again. The short program below can be kept in the root "$"
directory of all your discs, and when CHAINed will carry out several
'passes' until there is only one gap when *MAP is issued. Each pass takes
less time than the previous one, even if the same number of gaps result.
Occasionally, a disc can be very reluctant to compact below 2 gaps, though it
will make it eventually. The program therefore prompts you after 10 passes,
in case you don't want to bother to go the whole way. Typically, I found that
between 1 and 4 passes were needed with most discs.

You can alter the maximum number of passes via the variable T% in line 10,
and you can alter the number of gaps it will attempt to compact down to, via
the variable N% in line 10. (You will save a lot of time by increasing this
to 2, as long as this is sufficient for your purposes.) Do not alter the
variable A%. The program keeps you informed about how many passes it has
made, and shows the free space on the disc when it has finished. Note the
*COMPACT start page of 0F in line 20 to avoid corrupting the program itself,
which should reside at the normal PAGE setting of &E00. Therefore, if you do
add anything to the listing, even just a few extra spaces, then just check
that PRINT~TOP gives a Hex number starting with an E and not an F. The spaces
after the line numbers are shown for clarity only, and should be omitted.

 10 T%=10:N%=1:A%=0:REPEAT:MODE135:*MAP
 20 V%=VPOS-1:A%=A%+1:IFV%>N%ANDA%<=T%THENPRINT'"Pass ";A%:*COMPACT 0F 71
 30 UNTILV%<=N%ORA%>T%
 40 IFV%>N%THENPRINT'"Another try? ";:IFCHR$(GETAND&DF)="Y"THENRUN
 50 PRINT''"Compacted"':*FREE