Clarifications on the normal operation of the Apple Disk disk ][

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Clarifications on the normal operation of the Apple Disk disk ][

 

I having ascertained that my drive seems to work fine, I expose the following:When the computer is turned on, the drive initializes, remains with the red LED on and the engine running waiting for a (bootable) disk to be inserted. This status seems normal. After pressing the CTRL+RESET keys with consequent appearance of the cursor in the lower left part of the screen, the drive motor should stop and the red LED should switch off, but this does not happen. Even after inserting the floppy disk and successfully loading the program this does not happen. Is there anything abnormal or is it normal?

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No this is not normal. Ther

No this is not normal. The LED and motor should turn off after one second when the drive is no longer being accessed. There is a NE566 timer on the controller card that does this.

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jeffmazur wrote:No this is
jeffmazur wrote:

No this is not normal. The LED and motor should turn off after one second when the drive is no longer being accessed. There is a NE566 timer on the controller card that does this.

 

So the NE556 IC is not working fine?

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GianDO wrote:jeffmazur wrote
GianDO wrote:
jeffmazur wrote:

No this is not normal. The LED and motor should turn off after one second when the drive is no longer being accessed. There is a NE566 timer on the controller card that does this.

 

So the NE556 IC is not working fine?

 

 

I replaced NE556, but nothing changed

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GianDO wrote:I replaced NE556
GianDO wrote:
I replaced NE556, but nothing changed

 

 The next thing to check on the controller card would be the LS132 and the LS259. Otherwise, it could be the ULN2003 inside the drive itself. If you have another drive or controller card, that would narrow it down quite quickly.

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GianDO wrote:GianDO wrote
GianDO wrote:
GianDO wrote:
jeffmazur wrote:

No this is not normal. The LED and motor should turn off after one second when the drive is no longer being accessed. There is a NE566 timer on the controller card that does this.

 

So the NE556 IC is not working fine?

 

 

 

I don't know if that was super easy for you or not, but I think it would have been easiest to check the chip's output rather than swapping the chip.

 

Do you have any other hardware (card or drive) that you could swap for testing? How about a scope or logic analyzer? There are a couple things you could check but would be best to rule out either the controller or the drive.There's also a SAMS ComputerFacts Disk Drive Apple II book that may be helpful if you need to troubleshoot the drive.

 

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jeffmazur wrote:GianDO wrote
jeffmazur wrote:
GianDO wrote:
I replaced NE556, but nothing changed

 

 The next thing to check on the controller card would be the LS132 and the LS259. Otherwise, it could be the ULN2003 inside the drive itself. If you have another d

 

jeff d wrote:
GianDO wrote:
GianDO wrote:
jeffmazur wrote:

No this is not normal. The LED and motor should turn off after one second when the drive is no longer being accessed. There is a NE566 timer on the controller card that does this.

 

So the NE556 IC is not working fine?

 

 

I connected other units that I had available and the problem was the same. So the problem was not with the Apple DIsk II drive, but with the controller.So I replaced the IC 74LS132 as suggested and the problem was solved. Thank you.

 

 

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