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CBM 8050 DUAL DRIVE NOT WORKING

When you were trying the directory (in the video) I didn’t see the drive select lamp illuminating?

Also, the centre lamp goes red...

DS/DD disks should be OK.

You should see two green lights. The centre green lamp (between the two drives) and on the selected disk itself.

Dave
 
daver2 said:
When you were trying the directory (in the video) I didn’t see the drive select lamp illuminating?
Click to expand...
yes, led on drive unity stay off during directory mode...when i try formatting a disk, led is green!
 
>>> led on drive unit stays off during directory mode.

That’s clearly not correct. You still have some issues with the 8050 disk unit.

Dave
 
No great ideas from me yet but I'm watching this thread very closely as I have just picked up an 8050 (and a working 8032) with seemingly with the same current problem - drive powers up, passes internal self test but does not carry our commands from the PET. Status light seems to flicker with command comms but goes into a red fail state for each command. The drive heads don't seem to be moving on mine.
Need to get my other 8050 (was working) from storage to compare the two - and probably swap parts to narrow the problem down on this 'new' one.

Won't distract from this current investigation unless I have a light bulb moment for you....please carry on !
 
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So, what I am thinking is that the IEEE488 buffers in the disk drive could be faulty.

We can manually drive the signals from the PET to the IEEE bus to see what happens in the disk drive. But this will need some thought.

Dave
 
daver2 said:
So, what I am thinking is that the IEEE488 buffers in the disk drive could be faulty.

We can manually drive the signals from the PET to the IEEE bus to see what happens in the disk drive. But this will need some thought.

Dave
Click to expand...
Great! which integrated are the buffers?
 
zippysticks said:
No great ideas from me yet but I'm watching this thread very closely as I have just picked up an 8050 (and a working 8032) with seemingly with the same current problem - drive powers up, passes internal self test but does not carry our commands from the PET. Status light seems to flicker with command comms but goes into a red fail state for each command. The drive heads don't seem to be moving on mine.
Need to get my other 8050 (was working) from storage to compare the two - and probably swap parts to narrow the problem down on this 'new' one.

Won't distract from this current investigation unless I have a light bulb moment for you....please carry on !
Click to expand...
Hi! You can have bad 6530 (Rriot) maybe..... Do you have original or replacement RRIOT?
 
daver2 said:
So, what I am thinking is that the IEEE488 buffers in the disk drive could be faulty.

We can manually drive the signals from the PET to the IEEE bus to see what happens in the disk drive. But this will need some thought.

Dave
Click to expand...
Hi Dave do you speak about 3446 ics?? Thanks!
 
Correct, the MC3446's at UB1, UB2 and UD2.

The problem is that you are having to test them with the 6502 UN1 'live'. I am just wondering about removing some chips (e.g. UN1, UC1 and UE1 - the source and destination of the IEEE signals from the MC3446 buffers) to permit them to be fully tested from the PET itself.

Dave
 
daver2 said:
Correct, the MC3446's at UB1, UB2 and UD2.

The problem is that you are having to test them with the 6502 UN1 'live'. I am just wondering about removing some chips (e.g. UN1, UC1 and UE1 - the source and destination of the IEEE signals from the MC3446 buffers) to permit them to be fully tested from the PET itself.

Dave
Click to expand...
Ok what can i do to test these 3446??

I try to read directory with dual drive s' case open and i can see that floppy turn but the step-step motor doesn't move....
If i try to format, floppy disc turn and step-step motor it moves one step at a time!
 
Dave_C78 said:
Ok what can i do to test these 3446??

I try to read directory with dual drive s' case open and i can see that floppy turn but the step-step motor doesn't move....
If i try to format, floppy disc turn and step-step motor it moves one step at a time!
Click to expand...
That suggests its trying to format, but not managing to do it successfully so that when you try to read it, it cant

So, you format and the light remains green, then when you try to get a directory, the light goes red ? what error does the PET give.

The drives might need a head clean. or the floppy itself is defective.
 
Gary C said:
That suggests its trying to format, but not managing to do it successfully so that when you try to read it, it cant

So, you format and the light remains green, then when you try to get a directory, the light goes red ? what error does the PET give.

The drives might need a head clean. or the floppy itself is defective.
Click to expand...
Hi! When i try to read a directory, the center led flashing red/and green fast for 2 or 3 seconds and after come red....the led on drive unit stay off (d0 and d1).
 
The MOTOR ON signal (if memory serves me correctly) is separate to the DRIVE SELECT (indicated by the LED on the drive itself).

If the motor spins, but the disk drive LED doesn't come on - the disk drive will not respond to input signals from the controller electronics and will also not drive any output signals to the controller electronics. As far as the controller electronics are concerned, the disk drive is non responsive (hence the error).

The drive/PET maintains extended error information that can be read to indicate further details regarding the error that was observed. I can't quite remember how to access that at the moment (I am at work). However, if the drive LED doesn't actually illuminate, this will be 'odds on' for being an unresponsive drive, no index pulse detected or something similar.

You need to identify why the drive LED does not come on.

However, you have demonstrated it is not the LED, or the port bit driving the LED, that is at fault - because (under certain circumstances) the drive LED actually illuminates.

Dave
 
Hi Dave!
Yes when i try to format a disk, led on unit drive come green...
But we are sure that this led must stay green when i read directory? (in normal conditions)
Thanks
 
>>> But we are sure that this led must stay green when i read directory? (in normal conditions)

Absolutely, 100%... Unless it doesn't :)! Perhaps someone could check.

Does the motor spin when you try to read the directory? If it does, the control electronics are trying to read from the drive - and the only way that the disk drive will respond is if the LED is illuminated.

Dave
 
daver2 said:
Does the motor spin when you try to read the directory? If it does, the control electronics are trying to read from the drive - and the only way that the disk drive will respond is if the LED is illuminated.
Click to expand...
Yes motor spins but head doesn't move :( Im always more desperate for this bad Floppy :(
 
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