[Coco] Floppy drive setup HELP!

[Frank Swygert]

I recall a little about 5.25" floppies though I haven't messed with one (or a physical CoCo) in years! But I built all my floppy systems from scratch. 

If the cable is plugged onto the drive upside down the drive light will come on and the motor will run continuously. So it should be obvious if that's the problem. Even if you think it's not, flip the connector over. Try both drives on the same connector first, one at a time. It doesn't matter which connector is on a drive, it will still work. If the connectors have all teeth the drive will work as jumpered, if missing teeth it will work as the position in the cable -- first connector is drive 0, second one drive 1. Just issue a "dir" command for the cable position if missing teeth. Both drives need to be tested for both positions though. 

Some drives have termination resistor one one drive, some use a "distributed termination" with a smaller termination resistor on each. If you have an older drive in the D0 position look for a termination resistor. It will be an in-line pin item with 5-6 legs, either in a socket or with a jumper nearby. You may need to remove it from the first drive, and install/activate on the second. I seem to recall some floppies being set up this way, though it's most common on a SCSI buss. 

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Date: Tue, 13 Jan 2009 17:00:53 -0500
From: Gene Heskett <gene.heskett at verizon.net>

>I just looked at my 26-3029, FD-501 and FD-502.  They all have the key
>slot on the controller board. I no longer have any of the original
>cables supplied by Radio Shack so I can't say if the cable connectors
>were keyed or not.
>

Which prompted me to go play rat terrier in the basement for about 10 minutes.  
A 26-3022 does have the slot, Tony's 4n1 has the slot, 2 J&M's don't, and I 
wasn't able to find either the HDI or the short pack from the EDISK I built.

And like you, no original cables so I can't further declaim.  All of mine are 
keyless.  And I sit corrected.  My apologies.

But that does take us back to one of the drives is plugged in upside down 
doesn't it?

-- 
Frank Swygert
Publisher, "American Motors Cars" 
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