Help! Somehow NAK 2 drives.

[Bikerbob]

Hello all, not sure how I managed to do this.. but 2 drives now will not read.

 

1050.. which is the one I had for the longest time..

and an 810 which I got not too long ago..

 

I did download field service manuals, but most of that seems to be scope work.. and I have no scope..

 

Unless I have a power supply that could be damaging the drives, I have no idea what could be doing it..

 

They power, they seek and try and read, but get boot error or just wont read period.. and they both went at about the same time.. so its weird.

 

James

[Bryan]

I assume you've cleaned the heads?

 

A failing floppy can mess up your heads the instant you try to read it.

[Bikerbob]

Have not got there yet... I will do that tonight.. just ISOALCOHOL on a Cotton Swab?

 

James

[Bryan]

Yes. If you lift up the pressure pad, you'll see the top of the head. It should look similar to the picture, but extra brown marks on it are oxides from the disk. Gently scrub them off with the Q-tip/alcohol, and then go over it once with a dry one to make sure you removed all the liquid.

 

[Roydea6]

http://www.cpr-savers.com/assets/images/prodimages/M-314.jpg

 

 

Make it better than 70%

 

 

[ijor]

In my experience, you don't have to be very gentle when cleaning the head. As a matter of fact, sometimes you must be not gentle and use something like gauze pads, not qtips, applying some pressure on the head.

[Bikerbob]

Yeah I have the good stuff 99% ..

 

Fingers crossed.. jezz this is frustrating.

 

James

[Bikerbob]

Well.. not good news so far. The 810 worked once after cleaning.. and seem to read fine.. next boot.. back to the way it was.

The 1050 nothing better so far. I cleaned but nothing.

I tested all power supplies all give me 11.16v (rated at 9v ac)

SIO trick did not work on either.

I think its a head.. reading issue.. everything else seems to work fine.. spinning.. seeking.. power up .. but not reading.

James

[Rybags]

1050 gives the easiest indication as to whether it's a firmware/logic board issue or bad media or heads.

Just start the computer with the drive on with no disk and not closed. You should then get sets of 3 rapid beeps with each Boot Error message.

 

Either drive if you close it without a disk inserted should attempt seek operations if you attempt to boot it.

[Mclaneinc]

Greased the rails?

[Brentarian]

Have you checked the RPMs? I've never had a problem with 1050s RPM<>288, but have had to make RPM adjustments a few times on an 810 since the mid-eighties. Back then I didn't have any software that would show RPMs so it was a matter of turning the screw until it read a commercial disk. ?

 

http://www.page6.org/archive/issue_25/page_54.htm

[Bikerbob]

Have you checked the RPMs? I've never had a problem with 1050s RPM<>288, but have had to make RPM adjustments a few times on an 810 since the mid-eighties. Back then I didn't have any software that would show RPMs so it was a matter of turning the screw until it read a commercial disk.

 

http://www.page6.org/archive/issue_25/page_54.htm

 

Yes I remember this program.. but will this work if I boot from another drive and then hook up the bad drive ? if I can get the speed check program to read at least the RPM.. that should tell me communications are working.. if I cannot get the program to see the disk to check the speed.. hmmm where does that leave me??

[Bikerbob]

1050 gives the easiest indication as to whether it's a firmware/logic board issue or bad media or heads.

Just start the computer with the drive on with no disk and not closed. You should then get sets of 3 rapid beeps with each Boot Error message.

 

Either drive if you close it without a disk inserted should attempt seek operations if you attempt to boot it.

 

Rybags, I will listen for this.. but.. what are the other possible conditions.. 3 rapid beeps with each boot means good? if I get some other sounds.. what does that mean??

 

I tend to get that sound that sounds like really bad gas(the drive... jezzz people).. what does that mean??

 

James

[Rybags]

Relaxed fart sound generally means the computer is trying to talk to a device that's not present or the device just isn't responding.

 

The forced fart (or nose blow) - in fact your thread title has the clue. That is a device responding to a command by sending back NAK - negative acknowledgement. Either a bad command is being received or the device has a problem.

[Bryan]

He said "they seek and try to read" so I'm guessing it's either a head problem, the FDC, or the analog front end.

 

Also, if the 810 read once after cleaning then I'm still suspicious of the disks. Once that coating goes...

[AtariGeezer]

Possibly a dirt particle on the floppy that was used, causing it to scratch the heads of both drives?

[Bikerbob]

Ok, so this morning I started with the 810 and just went through disks.. it could read some... but not well.. on some disks I could even manage to load a game with some sputtering and retries etc.. but eventually it would load.. but other disks nothing.

 

Now on good drives those disks work fine.

 

I am wondering on the 810 about RPM.. that could reason why some disks read some stuff and other dont.. depending on the RPM when it was formated correct?

 

I cannot find the pot on the 810 to adjust RPM.. the software that can read RPM.. can I boot it from one drive and check another??

 

James

[Brentarian]

I'd have to open my 810 and take a pic in order to show you exactly where. I may be able to do that tonight if somebody else doesn't chime in.

In 1985 I had the exact same scenario with some disks working and some not. I didnt even realize there was a problem until I purchased a 1050 and noticed that it could not read any disks created and used on my 810. Fortunately a friend came over and with a small turn of the screwdriver set the RPM speed back to 288. But I then had another problem. There were at least 20 disks that been formatted and written to while the 810's RPM setting was wrong. Now with the 810 fixed, it couldn't read those 20 disks. I had to set the RPM back to the wrong value in order to read them and make a backup on the 1050.

SpartaDOS X has an RPM program built in. It should be accurate enough for testing the 810. I believe all you do is type RPM at the prompt.

 

[Bryan]

However, you cannot check speed until the drive works (without a strobe, that is).

[Rybags]

I wonder, could you do an alternate quick & easy RPM test:

 

. get a donor floppy, remove from it's jacket. Draw a straight line from centre to an outer point on the surface.

. insert into drive with top cover removed, take video with a camera set to known framerate (pref PAL/25 fps). A few seconds should be plenty.

. measure angular difference over a few sets of adjacent frames, do the maths to get RPM.

[1050]

As I've noted before like a broken record perhaps, you might try a shot of WD-40 inside the drive selector switches and work them while still wet 20 or 30 times. It is a returning issue here and does make the the drive think it's another number within the command sent, ACK, and complete action modes. All manner of errors and noises including just plain dead are possible when this a problem. Won't cost much to try, so just do it and be done with it already.

[Bryan]

Here's my quick analysis of everything so far.

 

1. It sounds like the drives are working at the controller level. They turn on, they spin, they stop, they spin again when you try to access them. They're just not reading. This means 90% of the drive is working.

 

2. They were both recently reading. This means the speed is probably not an issue unless you noticed a distinct difference in how the motor and spinning disk sound.

 

3. They both went bad at the same time. This usually means an old floppy disk is dirtying the head. The head must be 100% clean to work (see pic of an actual 1050 head). If it's dirty, you'll probably see other marks on it other than the black lines shown.

 

You also said the drives seek so I think it's narrowed down to just a few things. Unfortunately, the analog section is mostly soldered in. You can pretty easily swap a FDC though.

[Bryan]

As I've noted before like a broken record perhaps, you might try a shot of WD-40 inside the drive selector switches and work them while still wet 20 or 30 times. It is a returning issue here and does make the the drive think it's another number within the command sent, ACK, and complete action modes. All manner of errors and noises including just plain dead are possible when this a problem. Won't cost much to try, so just do it and be done with it already.

If the drive turns on and tries to run when you access it, then the selector switches are working (the drive knows its ID and is responding to it). If it doesn't respond at all, then the switches might be bad. I'd suspect the PIA first, though.

[Bikerbob]

I wonder, could you do an alternate quick & easy RPM test:

 

. get a donor floppy, remove from it's jacket. Draw a straight line from centre to an outer point on the surface.

. insert into drive with top cover removed, take video with a camera set to known framerate (pref PAL/25 fps). A few seconds should be plenty.

. measure angular difference over a few sets of adjacent frames, do the maths to get RPM.

 

I am serious! Were you being funny? quick & easy? LOL Rybags.. nothing quick and easy there..

 

I asked in another thread.. what about finding dumps of the Diag. carts.. programming a eprom put it in an old Basic board/cart.. would that work??

 

James

Edited June 1, 2016 by Bikerbob

[Rybags]

I was being serious. 288 RPM means the surface does just under 5 revolutions in a second.

That's pretty easy for a cheap video camera like a phone uses to capture.

You could put a piece of paper behind the rotating disk with 90 degrees worth of angles at 5 degree spacings.

288 RPM gives 69.12 degrees of rotation between frames at 25 FPS.

The way to guage speed woud be to go in increments of 52 frames. In that amount of time the rotation should equate to 3,594.24 degrees, in other words a little under 10 rotations.

When you're at 5.76 degrees behind the first frame, you'll be spot on.

At that time duration, the difference between 288 and 289 RPM is about 12 degrees so you'll have a reasonable amount of precision in the measurement.