Floppy controllers was Re: [Color Computer] [Coco]Re: Transfer utilities

[Robert Gault]

Too many variables mangled together here. Let's try to take one thing at 
a time.

Old controllers that use the 1793 chip, require +-12v lines. The Coco3 
does not have +-12v on the cartridge slot. Oh my, what to do! Two simple 
solutions are either use a Multipack or add a small perf board with + 
and - 12v regulators inside the Coco3 and wire the outputs to the 
cartridge slot. Connector 1 (top side) should be -12v, connector 2 
(bottom side) +12v. A perfect place to tap for power is the connection 
of D14 and C63 where there should be about 18v DC generated from the 
voltage doubler powering the RF modulator.

And speaking of hardware mods, while doing the above also consider 
cutting a hole under the keyboard to accommodate a box fan. A Tandy 12v 
0.15amp #273-243 works nicely and will keep your Coco memory running 
cool. Pull air in through the bottom and out through the top of the 
Coco. Really helps when 512K or more memory is installed.

For best results on any Coco floppy drive system, there should not be 
any missing wires or connectors on the ribbon cable. Drive number 
control should be handled by dip switches on the drive circuit board.

Glen VanDenBiggelaar wrote:

> 
> Oh, no I am treading into that "area" again over the 3.5 drives.
> I have been reading these list for a year now and no one wants to really 
> tackle that subject. Some sites say you can upgrade the  26-3022 
> controller to work with a 3.5" drive while others have said any 
> controller will work. I have tried a FD500 and 502 and neither seem to 
> see it (I have all the RS controllers kicking around -except the 501). 
> It looks like the Distro 2 can use it, but so far no one has said what 
> they are using for a controller and if it has been modified. This seems 
> to be the biggest "secret" of the CoCo, one that I have not been able to 
> see a clear answer in the last year anyway. My J&M systems controller 
> does not seem compatible with my FD502 drive because of a "Tooth" in the 
> cable that I cant seem to remove (not for lack of trying). When I 
> switched to an FD 500 drive, my CoCo 3 doesn't respond (I assume it 
> needs a multi-pak for the FD 500).
> -Glen
> 
> 
>