

                                 USERS' HACKS

Reverse head knock on the floppy drive

   Posted in the newsgroup comp.sys.cbm by Michael Parson
   (mparson@mercury.utb.edu):

   The following was taken from RUN magazine, Sept 1988 Issue, Magic
   Trick $4CC, page 12.

   If your 1541 or 1581 disk drive hasn't been behaving well lately, it
   may be out of alignment. You could take it to a repair shop, but
   before you shell out $0 or $50, try "knocking" some sense into it with
   my Reverse Knocker program.

   This 64- and 128-mode program reverse-knocks the drive head 100 times,
   which may re-align the drive just enough to postpone and expensive
   realignment. Be forewwarned: have an old work disk in the drive when
   you run it, and don't worry if running this program makes your disk
   drive sound like a smoldering Buddy Rich drum solo. It is a noisy
   program, but if you type it in correctly, it won't hurt the drive or
   disk at all.

0 REM REVERSE KNOCK YOUR DRIVE - STEPHEN CHEUNG
10 OPEN 15,8,15,"I"
20 SP=1:FORI=1 TO 100:GOSUB40:NEXT
30 FORI=1 TO 20:SP=-1:GOSUB40:NEXT:PRINT"ALL DONE!":PRINT#15,"I":CLOSE15:END
40 PRINT#15,"M-R"CHR$(0)CHR$(28):GET#15,A$:A=ASC(A$+CHR$(0)):BI=A AND 3
50 BI=BI+SP:BI=BI AND 3
60 R=(A AND 252) OR BI: PRINT#15,"M-W"CHR$(0)CHR$(28)CHR$(1)CHR$(R):RETURN


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    Marko Mkel (Marko.Makela@HUT.FI)

