Re: Help with //e-- disk drives

[Rubywand <rubywand@swbell.net>]

Andrew Lynch writes ...
> 
> I have an Apple //e and it wont work.  When i turn it on, all it does is go
> to the disk drive but it wont read the disk.  The disk work and it was
> working fine when it just stoped working.  Can anyone help me!

     Three fairly common causes for a 5.25" diskette 'suddenly not
booting' are Dirty R/W head, Diskette is messed up, and Drive Speed
needs adjustment.


Cleaning
     
     Cleaning your drive is a 'good try' fix, especially if it has been
a long time since the last cleaning. The easiest way to clean a drive's
R/W head(s) is with a Cleaner Diskette. This is a diskette with a paper
disk such as the 5.25" and 3.5 Cleaner Diskettes available in Radio
Shack's Disk Drive Head Cleaner Kits. These kits usually include
"Cleaning Fluid" (isopropyl alcohol), too.

     The 5.25" Cleaner Diskette has panels you pop out to expose the
cleaning surface. Apple II 5.25" drives have a single head which
contacts the disk from the bottom and a pressure pad which presses
against the top side. So, pop out the panel on the bottom side of the
Cleaner Diskette and leave the top panel in place. When cleaning, insert
the diskette with the bottom side facing down. This lets the paper disk
rub against the head and avoids wear on the pressure pad.

     The 3.5" diskette has a small plastic panel you can snap out for
cleaning two-head drives. Since the standard 3.5" 800k Apple II drive
has two heads, snap out the panel so that both the top and bottom heads
get wiped.

     To clean your drive head(s), you sqirt a few drops of Cleaning
Fluid onto the Cleaner Diskette disk, insert it into the drive, and get
the disk spinning for 20 seconds. (Booting the Cleaner Diskette is one
way to get it spinning. If DOS or ProDOS is installed, doing a CATALOG
is another way. For example: CATALOG,S6,D2 would get your 5.25" Drive 2
spinning.)

     If you think it has been several months since the drive was last
cleaned, repeat the procedure-- i.e remove the Cleaner Diskette, add
more fluid, etc.. As a rule, do not let the disk spin more than 20
seconds for any cleaning cycle. This is especially a concern with 3.5"
drives where the heads are mounted on springs and much more subject to
snagging and being pulled out of alignment. 


Messed up Diskette

     Once you are sure your drive heads (like on Drive 1 and Drive 2)
have been cleaned, try booting other game, etc. diskettes. If they boot
okay, the odds are good that a diskette which no longer boots is messed
up. Even so, a drive speed check and adjustment is worth a try.


5.25" Drive Speed Adjustment. 

     If you notice that some 5.25" diskettes-- especially commercial
game original diskettes-- do not boot as they should, you may need to
adjust your drive speed. (Many original game diskettes use copy
protection schemes which make the diskettes especially speed sensative.)

     If your drive is a Disk ][ and does not have the external 'Speed
Knob' mod, look for a small hole on the lower right side near the back--
some owners add this hole to allow easy access to the Speed Adjustment
mini-pot screw. If there is no hole, you will need to remove the case.
(Remove bolts on bottom and slide out the drive through the front.)  

     On the 5.25" Apple 'Platinum Drive', the Speed Adjustment is
accessed through a small hole on the bottom of the drive near the front
on the right side. Non-Apple 5.25" drives may place the Speed Adjustment
almost anywhere. Look for a small hole through which you can see a screw
head. If you don't fine one, remove the case and look for a mini-pot
labeled "Speed" or something similar.

     The most popular speed adjustment software utility is, probably,
dear old Copy II Plus. From the menu, just select "Verify", then "Drive
Speed". Put a blank or 'scratch' diskette into the drive you want to
adjust and, turning the Speed Knob (or min-pot shaft) use Copy II's
numeric speed display to zero-in on the 'magic' 200ms. number. (Standard
Disk ][ rotation speed is 300 rpm, which comes out to be 0.2 seconds per
revolution.)

     Other speed adjustment utilities show an rpm number or a hires
pointer. Whatever, all speed check routines need to read AND write; so,
you will usually need a "scratch diskette" which you do not mind having
over-written.


     Cleaning and adjusting drive speed will fix many 'disk won't boot'
problems.



Rubywand