Help with Apple IIc floppy.

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Help with Apple IIc floppy.

Hey all.

I recently got myself an Apple IIc, haven't used one since my early school days, but have always been wanting to get my hands on one.
For the last few days I've been trying to figure out what's up with the floppy drive... I'm hoping if I describe what's going on, someone with more knowledge can point me in the right direction.

The drive does work in some regards, but can't seem to read anything. For starters, when the computer it first turned on, either one of two things will happen. The drive will wake up, spin a second or so, and I get a "Check drive" message. Or, it will sit and spin indefinitely, not showing any message. Not sure which is the normal behavior.

When I boot up EsDOS with ADTPro, running 'INIT HELLO' causes the drive to go into the same infinite spin it does on bootup sometimes. I've let it sit for over 30 minutes, the read/write head never moving from the start of the disk. Now... I'm pretty sure the mechanics of the drive are okay. The disc does spin, and the read/write head does move.. when I first turn the machine on, it will move back to the start of the disk, and in one particular case (perhaps the init hello, don't recall) it will move forward a bit, then move back.. so it does seem to be able to move both ways. But when trying to actually read data, it never budges.

Suspecting it was the read/write electronics vs mechanics, I unplugged the header that goes from the floppy's read/write circuit to the head.. and the drive behaves exactly the same as when it's connected. After reading over the floppy information on 'APPLEBOX'? I decided to get a new MC3470N to replace the one on the board... currently waiting for that.

I also tried running some of the disk diagnostic stuff I was able to find, (ran via VSDRive/ADTpro), and they all behaved the same as INIT, hanging indefinitely as soon as it started, without the read head moving.

So yeah, I think I've rambled enough to cover what I've poked... any tips, suggestions, etc would be great.:)

Thanks!

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Re: Help with Apple IIc floppy.

Hello MrSiggler,
welcome at the board......
your guess is partially correct - but not complete.....:
it might be either the read or the write circits that are affected
therefor if you want to stay at the safe side - it´s recommended not only to
change the MC3470 but also the CA3146 and the 74LS125.
sincerely
speedyG

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Re: Help with Apple IIc floppy.

Many thanks. I've gone ahead and ordered those two chips as well Smile

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Re: Help with Apple IIc floppy.

I'm thinking... Clean the read/write head...

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Re: Help with Apple IIc floppy.

I recently restored a //c and even though I had thoroughly cleaned the head, I was still having issues. I happened to give the head one more pass with the isopropyl and it came good, so it's worth cleaning that sucker thoroughly to completely rule it out.

Could be something else wrong here though.

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Re: Help with Apple IIc floppy.

I have to agree with everyone, but the rule
"Cleanliness is next to Godliness" ranks high on the
IIc drives. A good cleaning is the first choice for these machines.

It has worked many times for me.

And Welcome to Applefritter!

Steven Smile

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Re: Help with Apple IIc floppy.

Thanks guys, but I cleaned the head with isopropyl several times, I just forgot to mention that Wink

How I wish shipping from China wasn't so sloooow.... lol

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Re: Help with Apple IIc floppy.


How I wish shipping from China wasn't so sloooow.... lol

Which country are you located ?

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Re: Help with Apple IIc floppy.

I'm in Canada. The chips I ordered are from USA and the Netherlands, but I wanted to put them all into sockets, which are from China, which usually means a months wait Wink

speedyG's picture
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Re: Help with Apple IIc floppy.

so patience is demanded.....
just asked to see if i could refer to alternate sources....
but USA to Canada and Netherlands to Canada is only a week delay....
In case you search next time for sockets or other stuff:
http://www.jameco.com/webapp/wcs/stores/servlet/StoreCatalogDisplay?storeId=10001&catalogId=10001&langId=-1&rfr=1
thats one of the most common suppliers in the US for internet shopping of such items...

sincerely
speedyG

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Re: Help with Apple IIc floppy.

Jameco...

The friend of Apple II repairers. LOL

Steven Smile

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Re: Help with Apple IIc floppy.

Ah, thanks Smile Next time I need parts like this, I'll check Jameco before eBay.. Wink

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Re: Help with Apple IIc floppy.

Hey again!

I got all the parts, and tried various combinations of the ICs to see which if any fixed the problem..
Looks like the problem was the 74LS125, the other two original ICs(CA3146/MC3470) are still good. I was able to INIT a few disks, and using ADTPro create a few bootable disks!
Many thanks for the help Smile

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