[Coco] 3.5 drives was drive motors

[Bruce W. Calkins]

As others have touched on, PC drives are jumpered as drive 1 and the cable 
has a twist to swap the drive select 0 and 1 lines between the drive 
connectors.  Some of the now really old 3.5 drives have jumpers of switches 
for drive select with the default setting as drive 1.  Fewer and fewer of 
the newer drives have any drive select settings available.  With those newer 
drives you will need to figure out where the drive select lines are and 
figure out the proper twist to put the correct line in the cable into the 
drive 1 position of the applicable drive.

Also, 720k media is the only reliable choice for the CoCo use, unless you 
have a 26-3022 controller modified for the faster data transfer rates needed 
for the 1.44M media.  On my CoCo systems I have had good luck through the 
years with 1.44M drives using 720k media.

Bruce W.

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----- Original Message ----- 

From: "Lothan"

> Actually, the drives are pin-for-pin identical. The difference is whether 
> the drive has jumpers for drive select or has drive select soldered in 
> place for a PC (in which case it may need some portion of the cable 
> twisted to swap drive select). Way back in the day I had a couple of Teac 
> 3.5-inch drives with drive select jumpers, but (as Gene indicates) these 
> may be as rare as hen's tenth today.
>
> -----Original Message----- 
> From: Bill Pierce

>
> Robert,
> I'm not sure but I think the two connectors are not pin for pin 
> compatible. I seem to remember that you have to switch a couple if not 
> several pins to make it work properly. One of my 3.5 drives (my current 
> drive 0) came configured for the Coco with a case and an internal 5.25 to 
> 3.5 adapter plate with an 34 pin adapter on the plate. A regular Coco 
> drive cable is used, then internally it cables to a 34 pin connection like 
> used on the 3.5 drives. In the cable run, from the internal side of the 
> card edge to the 34 pin, there are several wires crossed to other pins. 
> They are not direct pin for pin connected. I also have a cable that is set 
> up for a 5.25 and a 3.5 drive. In that cable, after leaving the 5.25 
> (drive 0), several wires are split from the ribbon and crossed to 
> different pins for the 34 pin 3.5 connector. I know I'l be corrected if 
> I'm wrong.