Apple II...DISK II...calibration ???????

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Joined: Jan 19 2011
Posts: 31

Hi mates

i have a new..OLD Smile Pravec 82 /apple II+ clone/ with two DISK II drives
i cleaned the HEAD of both of them
but i think /i remember/ must be have some calibration methoods for SPEED and POSITION FIXINF of HEAD /or MOTOR of this drive Smile ?
so.. how was this callibration .. software..for testing ..and ALL is ACCEPTED for HELP ..me Wink

tnx in advance Smile

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Offline
Joined: Dec 13 2005
Posts: 264
Re: Apple II...DISK II...calibration ???????

Hi,
What kind of drives are they? Apple or 3dr party? 3dr party drives may be different then Apple drives to calibrate. Speed adjustment may be the same with a small jewelers screwdriver. A picture of them would help. You might if you careful and know what you are doing and switch them so 1 is 2, and 2 becomes 1. But if you put the wires on wrong well all bets are off. If you can boot one copyII+ has speed adj built into it. You have to use a blank disk because it will destroy any data on the tracks to perform the speed test. Some drives vary more than others.

You have not said what you have tried or what is it doing? You need software that was know to work. Right slot that it was put in, what else did you try to do and the responce tom it. Maybe a PR#6 boot might work.

More info and some pictures may help. But their will other questions once that is given.

Take Care

gsmcten's picture
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Joined: Oct 4 2005
Posts: 2626
Re: Apple II...DISK II...calibration ???????

This information was covered in another post several months ago. You might go to the Apple II forum, plug in "Disk II", or "Calibration" and it might take you right there.

Good Luck Smile

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Steven (gsmcten)

"Apple ][.....It's ALIVE!!!!!"

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Joined: Dec 19 2003
Posts: 832
Re: Apple II...DISK II...calibration ???????

I think a strange error happened with the AppleFritter message routing system as I got a PM from drjones on this topic. Oh well. I still have an answer. I'm going to make a list of the 5.25" floppy disk drive maintenance procedures that I got from SAM's guide that works for me:

1) Disconnect the drive from the computer. Put on an anti-static wrist band to protect the circuitry. Discharge any capacitors safely.

2) Open up the drive housing and clean out any dust, grit, hair, food, etc.

3) Clean the magnetic head by wrapping a cotton ended ear swab (Q-Tip) with a nylon stocking. Dip it in ANHYDROUS alcohol (also know as electronics cleaning alcohol), and clean any residue off of the head(s), swapping in new swabs as the old ones collect residue (dark patches of dust).

4) Check that any rubber drive belts are intact and have decent tension.

5) Speed Calibration Instructions v1.0: For Disk ][ drives there is a black and white pattern on a flywheel in as part of the mechanism. While the disk is spinning at the desired optimal speed, while viewed under an incandescent light bulb from a power source operating at 60 hertz (standard house wiring in the USA) the black and white pattern will appear as a set of stationary lines. Insert a blank disk and close the drive door. Attach the drive to the computer. Find the speed adjustment potentiometer (pot) and with a small screwdriver be ready to adjust it while watching the flywheel pattern. Boot the drive and while it is spinning adjust the pot until the pattern stabilizes. Close it all up. Your drive is now speed calibrated.

-OR-

5) Speed Calibration Instructions v2.0: Duodrive, Apple //c drives, and other Apple brand 5.25" drives that aren't Disk ][ drives are a bit more closed than the Disk ]['s and slightly better engineered so they don't need cleaning or speed calibration as often. They are also a bit more of a hassle to open. On the bottom of the drive there will be a small access hole for inserting a small flat blade screwdriver to access the calibration pot. You will need to have a functioning drive, as well as your semi or non-functioning drive connected to the computer. With the functioning drive, run Copy][+ or any of a number of disk drive utilities that have a built-in drive speed calibrator software feature, and access it. It will ask which drive you want to (speed) test. Tell it and start the test (spinning the drive the whole time). It will report back the speed and indicate if it is within operation range. Adjust the pot until the drive is within the operating range. Your drive is now speed calibrated.

For those with epilepsy or flash photography sensitivity, don't use instruction 5.1, use 5.2. You can use instruction 5.2 for any 5.25" floppy drive type/brand.

Mutant Pie

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Joined: Jan 19 2011
Posts: 31
Re: Apple II...DISK II...calibration ???????

tnx A LOT
.........
one DISK drive is OK now
another is not ..and can't be calibrated Sad
the speed has changed ..on any 10-15 seconds /from 199-200ms..to 70 or 120 or 150 ..and in that moment.. floppy stop reading..correctly Sad
but this can't be fised...by resistor calibration Sad

Offline
Joined: Dec 19 2003
Posts: 832
Re: Apple II...DISK II...calibration ???????

Glad you got one drive going well. With the other one it could be a bunch of different things, but probably is a slipping (old/loose) drive belt, or the motor is starting to go. You could try applying a drop of oil to the ends of the motor shaft where it meets it's housing, or replacing the drive belt, or both.

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Joined: Dec 19 2003
Posts: 832
Re: Apple II...DISK II...calibration ???????

Actually I should make an addendum note to Disk Calibration instruction v5.1. There are TWO SETS of interference patterns on the fly wheel, one for calibrating with light bulbs flashing at 60 hertz, and one flashing at 50 hertz. I think that 50 hertz is used in most of the world, but I'm not sure.

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Joined: Dec 13 2005
Posts: 264
Re: Apple II...DISK II...calibration ???????

I think it might be the read write chip may be bad or server oxidation to the chip. The legs on these socketed chips turn black. Chips have to be taken out and cleaned with Tran-X. If they are soldered in then it does not matter if they are oxidized because they will have a good connection. I kind of doubt the belt slipping. Now some floppy disks do not spin nice in their sleeves. If you have a floppy disk that does not spin well or bad clamping this can cause the problem. That is using disks that do not have the metal hub in the center. Sometimes they fall off with age. Sometimes people use the wrong type of disks. The HD 1.4meg disks do not have hubs. They can slip while Spinning. They may not hold the data long either. You need to use the right kind of 5.25 disk. Which are Double Density with a center metal hub.

Take Care

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Joined: Jan 19 2011
Posts: 31
Re: Apple II...DISK II...calibration ???????

..hmm this read/write chip is oxydated..really ../black legs.../ must find this fluid for cleaning and try to clean legs..
..the belt is ok.. i thing ...
so will keep U guys informed...after trying to clean legs..

tnx a lot for now ! Smile

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Joined: Dec 13 2005
Posts: 264
Re: Apple II...DISK II...calibration ???????

Hi
Tran-X is a Jewelry cleaner. It cleans Gold and sliver, and copper with just dipping it. Removes no metal. Should only need a shot glass full. DO NOT DRINK IT. Remove the the chip and dip it. Rinse it with Isopropol Alcohol. Let drive. MAKE NOTE of WHERE THE NOTCH OR DOT IS ON THE CHIP SO YOU PUT IT IN THE SAME WAY. Your clone might be more like the Franklin Ace on the Drives. If so their may be another adjustment that might help. Would need a picture of the Anolog board of the disk drive.

Would have be back home to compare it to.

It might be easier to just replace the chip. Their is always the possibility that it may be bad. But it might have taken a something else with it.

Do you have any unusual software that came with the clone.Now that would be interesting?

Take Care

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Joined: Jan 19 2011
Posts: 31
Re: Apple II...DISK II...calibration ???????

..will go to any Jewelry master Wink to get some fluid Smile

in bulgaria was maded 2 models /disk II drives/

one is almost 100% copy of orginal Apple drive /el. board too/ the diference is only on 2-3 CHIPs on board

another drive is wery different ....bigger el. board and architecture of lines and chips

must make some pictures .. :0

for software .. i dont think ....we have some unusual softwares... all is cirilyc clones of orginal :0
i remeber one
TALKIN PROGRAM /who speach every typed word.. ? but maybe this is clone to Wink ?

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Joined: Jul 6 2009
Posts: 44
Re: Apple II...DISK II...calibration ???????

Hi

If you understand bulgarian, I can send you an .DSK image of "ZASIKA" - a test program for the IZOT full height drives (model ES5088.02). I think most test will work on any drive.

I also have some test for IMKO2 (the prototype for Pravetz 82, manufactured in small quantity in Bulgarian Academy of Science). They are mostly translated Apple II tests.

Stefan

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Joined: Jan 19 2011
Posts: 31
Re: Apple II...DISK II...calibration ???????

..of corse i know bulgarian Smile

IZOT are well known to me from 198? Smile
and i have Pravec 82 Smile /IMKO 2 is same :0 just BOX is from METAL ...pravec 82 is from plastic Smile

send me all of them :0

georgi.taushanov@gmail.com

i will try to find some bulgaian programs.. but they will be on cyrilic Wink

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Joined: Dec 19 2003
Posts: 832
Re: Apple II...DISK II...calibration ???????

Twilight_Rodent,
Thanks for sharing this great tip! How do you clean the sockets?
Mutant Pie

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Joined: Dec 13 2005
Posts: 264
Re: Apple II...DISK II...calibration ???????

Your are welcome.
I have posted this a few times. Usually you will have more than one chip that is oxdidized. You only want to do one at a time. Do all the ones that go a certain way in the sockets then do the others. It helps if you have another board to look at to see how they even doing one at a time.
Then I would have multiple shot glass full of Isopropl Alcohol set up to clean them in. After 4 or dips I would get rid of the first shot glass of Alcohol, number 2 would now become number one. The last shot glass would be fresh one for awhile. Water might work, but it takes a while to dry. But Alcohol dries quicker and also cleans like water.
Sockets are another story. They do not turn black. But they can become dirty and chrome like surface may oxidize also. Certain chemical contact cleaners with a clean tooth brush should work. Contact cleaners were easy to get when all TV had rotary Tunners. The one you had to manually get and turn to change the stations. Isopropl Alcohol is good too. You want to get the ones whit the higher percent as it has less water and dries quicker. With sockets you would almost have to use compress air, Hair Blow drier and time to let them dry out, because you are never really sure how dry they are. You can never see under them.

Take Care,
George/Geo3/Grent

A2forever's picture
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Joined: Dec 20 2003
Posts: 226
Re: Apple II...DISK II...calibration ???????

You can also use Copy ][ PLUS to set up disk calibration speeds right? I have a moded drive with an adjustment pot on the front of one of my Disk ][ Drives and I can bootup Copy II PLUS and manually set the speed calibration and it works like a charm with Copy II PLUS. Just a thought .

Patrick.
A24ever.

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speedyG's picture
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Joined: Nov 16 2011
Posts: 2413
Re: Apple II...DISK II...calibration ???????

Hello drJones,
its probably a good idea ro visit my name here and look to "track". You will see that i have written basic pages about the DISK II and calibration of drives... there are also a lot of basic explenations and pictures.... just follow the links that that i published there...
sincerely speedyG

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the second part includes less friends but a lot more joy on life....

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Joined: Jan 19 2011
Posts: 31
Re: Apple II...DISK II...calibration ???????

tnx to all Smile
and expecialy to SpeedyG ")
but i forgoten to END this post in MAY 2011 Smile
i already calibrated all Wink

now i have RGB card problem Smile ... /in other post/