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f1lm
July 28th, 2011, 05:24 PM
I just grabbed myself a Kaypro II, knowing of some disk problems. I figured it'd be an easy fix but I'm being disproven. I can't seem to figure out what's wrong with it.

It won't take any of the numerous CP/M disks I'm putting in it, just saying it can't read it, and I'm afraid it might be eating up the disks.

I can't describe the problem all that well, as I don't know what relevant details I should include, but if there's more details you guys need I'll do my best to provide the information.

Currently I'm thinking of taking the FDDs and swapping drive B with drive A, but my first test of simply unplugging drive A and putting its plug into Drive B didn't work as expected.

Anyone have some ideas? I'm a newbie to CP/M, and I'm sorry if this is the wrong forum.

tezza
July 28th, 2011, 07:27 PM
I just grabbed myself a Kaypro II, knowing of some disk problems. I figured it'd be an easy fix but I'm being disproven. I can't seem to figure out what's wrong with it.

It won't take any of the numerous CP/M disks I'm putting in it, just saying it can't read it, and I'm afraid it might be eating up the disks.

I can't describe the problem all that well, as I don't know what relevant details I should include, but if there's more details you guys need I'll do my best to provide the information.

Currently I'm thinking of taking the FDDs and swapping drive B with drive A, but my first test of simply unplugging drive A and putting its plug into Drive B didn't work as expected.

Anyone have some ideas? I'm a newbie to CP/M, and I'm sorry if this is the wrong forum.

Floppy reading problems have been discussed numerous times on the forum. Essentially it's a case of:

Disks are bad (degraded disks can leave deposits on the heads and scratch other disks)
Drive heads are dirty (clean em)
Drive speed is wrong (remove drive and check with the strobe patterns on the flywheel)
Problems with the cable (check for broken pins etc.)
Drive alignment is out (less likely than the problems above. Alignment is more difficult to fix than the other above but not impossible)
Problems with the drive electronics (possible, but check the above first)
Problems with the drive controller
With the Kaypro II you will have to do more than just swap cables. On the drive there will be a jumper specifying the drive number. This will need to be changed around (the lowest number for drive A, and the next highest one for drive B). There is usually a resistor that will need to swapped also (often it is blue and looks like an IC). It should be on the drive at the end of the drive cable (normally drive A).

Hope this helps.

Tez

pavery
July 29th, 2011, 01:55 PM
... just saying it can't read it, and I'm afraid it might be eating up the disks.


Specifically what is the screen displaying?

Scenario 1: Drive A spinning, sits at "Please place your Diskette in Drive A"
FDC is not receiving data. Disk may be unformatted or Data Separator fault? If D/S fault, disk may have been corrupted. Verify disk.

Scenario 2: "I cannot read your diskette."
Data is reaching FDC ok. Likely causes: Diskette is not a system disk or system disk is damaged.

Philip

GADFRAN
July 29th, 2011, 04:14 PM
Thanks Tez !

He needs to explore this site more for more info !

Then get back with better questions.

Frank

gubbish
August 1st, 2011, 10:24 PM
Hi,

I just got a kaypro 2 myself and also have some FDD issues.
This particular Kaypro just says "KAYPRO" on the side and not kaypro 2, but there is a Kaypro 2 sticker on the back.
It has 2 vertically mounted FDDs.
Specifically, here's what happens.
Turn on the computer, and the Kaypro message appears on the screen. Drive B spins, then Drive A and stays on drive A.
When I insert a Kaypro CP/M boot disk created with Imagedisk on a 360k drive, when I close the drive lever, it does not stay closed and immediately ejects the disk. As soon as I turn the lever to a certain angle, a message appears that says "No operating system present on this disk". But it does not appear to be reading the disk at all, the moment the lever is turned the message appears. And the lever will not stay closed, it immediately springs back and ejects the disk.
Has anyone seen this behavior before? Seems like there might be a mechanical problem in the drive. Perhaps some locking mechanism needs to be cleaned inside the drive. Thanks..

Chuck(G)
August 1st, 2011, 10:45 PM
Kaypro 2 != Kaypro II.

And yes, it sounds like a mechanical problem. The Kaypro II usually uses FH drives; the much later Kaypro 2 uses HH drives.

gubbish
August 1st, 2011, 11:06 PM
This one does have HH drives. Next opportunity I will open the Kaypro up and take a peek at the drives to see if I can find anything obvious.

atod
August 2nd, 2011, 03:57 AM
If I suspect a drive problem on a system like this, the first things I do is swap the drives. A becomes B and B becomes A. Usually drive B sees less use and therefore should be in better condition. On the Kaypro, you pretty much have to get a screwdriver and pull the whole thing apart to get at the drives. Then like another poster replied, change the "drive select" jumpers, essentially swapping the jumper config between the two drives. You will need to find the manual for these drives online to figure out where these jumpers are. You will also need to move a "resistor pack" from drive A to drive B (which will now become A). It looks like a IC and is usually white.

My Kaypro II had a mechanical problem with the drive lever. Someone was kind enough to send me a replacement plastic lever. I tried fixing that lever with MEK solvent to weld the plastic, however it didn't hold. I'm wondering if it's made out of Nylon. If you can't find the lever you may want to search craigslist for an old IBM 5150 PC and steal it's drives.




Hi,

I just got a kaypro 2 myself and also have some FDD issues.
This particular Kaypro just says "KAYPRO" on the side and not kaypro 2, but there is a Kaypro 2 sticker on the back.
It has 2 vertically mounted FDDs.
Specifically, here's what happens.
Turn on the computer, and the Kaypro message appears on the screen. Drive B spins, then Drive A and stays on drive A.
When I insert a Kaypro CP/M boot disk created with Imagedisk on a 360k drive, when I close the drive lever, it does not stay closed and immediately ejects the disk. As soon as I turn the lever to a certain angle, a message appears that says "No operating system present on this disk". But it does not appear to be reading the disk at all, the moment the lever is turned the message appears. And the lever will not stay closed, it immediately springs back and ejects the disk.
Has anyone seen this behavior before? Seems like there might be a mechanical problem in the drive. Perhaps some locking mechanism needs to be cleaned inside the drive. Thanks..

dabone
August 2nd, 2011, 06:46 AM
If you are just changing the drive id jumper, why would you move the resistor pack? It should stay on the last drive on the cable correct? So if you swapped the drive 0 and drive 1 jumpers, but left the cable the same, the resistor pack wouldn't move. (If you swapped the drives, and cable placement then yes the pack would need to be moved)

Later,
dabone

Chuck(G)
August 2nd, 2011, 08:22 AM
If you are just changing the drive id jumper, why would you move the resistor pack? It should stay on the last drive on the cable correct? So if you swapped the drive 0 and drive 1 jumpers, but left the cable the same, the resistor pack wouldn't move. (If you swapped the drives, and cable placement then yes the pack would need to be moved)

Given the slow speeds of floppy logic and the short cables used to connect floppies to the controller, the position (and, within limits, the value) of the termination resistors doesn't matter much--what is important is that the drive chain be terminated with a pullup on controller output lines. Any value from 1K to 150 ohms is usually acceptable--and if you use, say, 470 ohm termination packs, both drives can have them without harming anything.

You have to remember that the termination scheme originally came from the need to have the drives separated by a couple of meters from the controller. Make those lines long enough and you'll eventually get ringing problems. But that just doesn't happen with computers made after, say, 1980.

gubbish
August 2nd, 2011, 07:14 PM
I do have a 5150 with working floppy drives, so I could try one out to see if it works. I also have a half height IBM qumetrak 360 drive which is currently in a pentium tower, to create floppy images. I read through the Kaypro technical manual and looked at the various drives that were used, and how to add the terminator resistor. Any idea how I would do this with one of these IBM drives, if it's possible?

Chuck(G)
August 2nd, 2011, 07:39 PM
All of those you mentioned have space for a terminator.

MikeS
August 3rd, 2011, 11:31 AM
All of those you mentioned have space for a terminator.Just leave the drive with the terminator at the end of the cable and replace the one in the middle (preferably without a terminator), swapping DS if/as necessary

gubbish
August 3rd, 2011, 12:00 PM
Thanks for the info.
Made some progress on this, thanks to the appearance of another Kaypro 2 on my local craigslist, which I snapped up.
The second Kp2 was not immediately functional, and made a periodic chirp type noise which happened about twice a second.

Opened up Kp2.1 and Kp2.2, and took a look at the always-ejecting drives of Kp2.1. A small plastic piece which pushed the top part of the drive mechanism down onto the floppy was slightly cracked, and was at a slight angle. Looks like friction of this piece against the metal was supposed to keep it in place against the force of a spring pulling it back up. The crack and angle of the piece was keeping it from holding the drive mechanism in place and the force of the spring was just pushing it back up right away. I was able to push this piece slightly, rotating it about the metal rod on which it was mounted. I put a few drops of glue into the cracked bit. So far it is holding and the drive can stay closed, but we'll see.

In any case, with Kp2.2 I got some original Kaypro disks, so I had some original CP/M disks to try just in case my disk image was bad.
I decided to try replacing drive A in Kp2.1 with a half-height IBM Qumetrak drive. I changed the jumper to DS0 on that drive, and kept drive B (with the terminator pak) connected. Then I tried to boot from the CP/M disk image I had made earlier. The behavior was the same as I had observed before - the moment I put the lever down on the qumetrak, the message "No operating system on this disk" appeared on the screen and the drive stopped spinning.
Trying this with one of the original CP/M disks, now when I put the lever down, the drive head immediately moved all the way forward and started clacking loudly. It looked like the motor was trying to push the head forward and running against the physical stop of the drive.

So now I had seen the machine fail to boot from what I knew was a working drive. I next removed the mainboard from Kp2.2 and tried connecting it to the hardware from Kp2.1. Using the same CP/M disk, I turned the machine on and it came right up to the CP/M prompt!
Removed the qumetrak and connected the original drive from Kp2.1. Still booted right to CP/M.
I could copy the CP/M disk to a new disk in drive B, so it looked like Kp2.1's drives were working except for the mechanical fault in the plunger piece.

So it looks like there may be an issue on the mainboard of Kp2.1. And I thought that the original problem with Kp2.2 sounded like a power supply fault (no boot, no drive activity, only a 2hz clicking sound). I took the power supply board from Kp2.1, put it into Kp2.2, and restored the original mainboard of Kp2.2. And it worked, both drives seem fine.

I also discovered that I had not created the CP/M disk image properly. After putting the qumetrak back in the pentium machine, I ran imagedisk again and more carefully set the settings to single sided, single stepping, and ran it again. This time the CP/M disk image booted properly.

So now, Kp2.2 is working with a replacement PS. And it looks like the floppies from Kp2.1 are working, but there is likely an issue on the mainboard which keeps it from booting. I'm guessing that there may be a fault with the drive controller part of the mainboard. I don't have much knowledge of Kaypros so I'm not sure what that entails. And in order to get Kp2.1 working, I will need to fix the broken PS or replace it. Seems possible to use a more modern PS unit instead.

Sorry for the long winded description, but just happy to have a working Kaypro!

atod
August 3rd, 2011, 02:08 PM
Do you have an Imagedisk PC to connect the Kaypro drives to? That way, you can validate they work in DOS without depending on the unknown condition Kaypro components.