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CBM 8050 DUAL DRIVE NOT WORKING

If the drive LED does not come on - the head will not move because the disk drive has not been selected (it thinks).

All the problems are tied together.

I suspect the fault is on the logic board somewhere - not necessarily the disk drives.

Dave
 
If the drive LED does not come on - the head will not move because the disk drive has not been selected (it thinks).

All the problems are tied together.

I suspect the fault is on the logic board somewhere - not necessarily the disk drives.

Dave
Yes....can i try to buy new 3446??
 
Why do you want to buy one, we can test them 'in-situ' if we come up with the right procedure.

I am just a bit too busy at the moment. I have some leave on the 1st April - so I should have some more time then...

Dave
 
Why do you want to buy one, we can test them 'in-situ' if we come up with the right procedure.

I am just a bit too busy at the moment. I have some leave on the 1st April - so I should have some more time then...

Dave
Im sorry that you're too busy in this moment :(
Maybe can i try 3446 ic pins with logic probe during "Directory" command???
 
>>> Im sorry that you're too busy in this moment.

Don’t be, I get paid well for it!

Can you monitor UB2 pin 4 with your logic probe please and post back what the logic value is.

Next, can you enter the following three commands on the PET whilst monitoring UB2 pin 4 and post back the logical value is after each POKE command please.

poke 59456,4
poke 59456,0
poke 59456,4

These immediate mode commands should toggle the state of the IEEE pin /ATN from the PET to the 8050 and you should observe this change of state on UB2 pin 4 of the 8050.

We can then try the data bus from the PET to the 8050 next if this signal is OK.

Dave
 
Thanks!
UB2 PIN 4 normal status: PULSE

After POKE 59456,4: PULSE
After POKE 59456,0: PULSE
After POKE 59456,4: PULSE
 
That’s what I feared, the PET is manipulating the IEEE port whilst it is in ‘command’ mode.

My initial idea won’t work then!

Can you write a simple program instead:

10 poke 59456,4
20 input a$
30 poke 59456,0
40 input a$
50 poke 59456,4
60 input a$

Run the program and monitor the state of UB2 pin 4. Just a thought, you are checking UB4 on the 8050 disk drive aren’t you and not the PET?!

The PET should be waiting for input. Press the Return key and monitor the state of UB2 pin 4 again.

Press the Return key again and monitor the state of UB2 pin 4 again.

Dave
 
Strange situation!
Now i turn on Cbm and Floppy, i rechecked UB2 pin4 (always on dual drive) and i have low signal...also if i run program.. :(
 
Are you pressing the RETURN key on the PET as well to move the program on?

There is an input statement to wait for you to press the RETURN key...

Dave
 
Don't be desperate. daver2 can help you fix any problem.

Also if it turns out there is something expensively wrong with your 8050, you can always get this to solve all your disk storage wants:

https://www.thefuturewas8bit.com/sd2pet-future.html

Also bitfixer.com is almost out with an improved version of PETDisk MAX that uses wifi. Either transfer PET programs from the internet right into your PET or use the standard SD card method like the other disk emulators.

So hang in there.
-dave_m
 
Hi Daver2,
i tryied to tips this little Basic program (as ing. @iz8dwf in other post) but i don't understand error message :(
 

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Well, the first error report implies that something did go wrong with the IEEE protocol (possibly) if it is saying there is no filename. This could also be due to a RAM fault also.

The second error report implies a read error from the disk drive itself.

When you were performing these tests, did you note down whether the drive LED was illuminated or not?

Dave
 
Well, the first error report implies that something did go wrong with the IEEE protocol (possibly) if it is saying there is no filename. This could also be due to a RAM fault also.

The second error report implies a read error from the disk drive itself.

When you were performing these tests, did you note down whether the drive LED was illuminated or not?

Dave
Yes always green led, i re tryied now and i see this on screen:
 

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Great news!!!
I taked other floppies in my cellar and i tryied other 5 disks....the last disk that i used (3m dd) works!!!!
Format ok and dir ok ;)
 

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