Here is some help for all you guys that want a decent drive to put 
into your ATARI; either to replace a broken drive or as an after 
market item to replace your current ATARI drive.

You can put a nice bullet-proof TEAC drive in you computer even 
cheaper than you or your dealer can buy an ATARI drive.  Your cost 
will be only $57.00 give or take a buck or two plus the shipping 
if you mail order.

You can order these little beauties from several outlets listed in 
Computer Shopper or Byte or about any IBM oriented magazine.  Shop 
the adds a little you should not have to pay more the $55 to $60.  
Ask specifically for a TEAC 720K floppy drive (model FD235F if you 
really want to impress the salesman).

When you receive the drive all you have to do is pull the RDY 
jumper from the drive and move the drive select jumper from D1 to 
D0 (FIGURE 1).  Then you turn the drive over, heat up the old 
soldering iron and lift the inner tab on the high density select 
sensor box in the front left corner (check out the IMG diagrams 
with this file on where to find these).

Now pop this drive into your 1040 or MEGA and fly.  On a 1040 you 
will have to flip the ribbon header over when you plug it to the 
drive.  If you do plug in the drive and it doesn't work don't blow 
your kool.  Just flip the cable over and try it again.  It will 
go.

The only thing you have to be concerned about is that you do not 
cross plug the power connector.  The TEAC drive only requires 5 
volts to run.  Not an entire hydro generating facility like the 
ATARI drives.  If you want to be really safe clip the 12 volt line 
on the ATARI drive plug.  That's the BLUE wire (you may want to 
check this with a meter to make sure... some computers may have a 
different color code... it is the outboard pin, farthest left 
looking at the back end of the drive) going to your drive that 
will keep the volt killers away.

You will have to either put spacers under the drive in the older 
1040's to bring these beauties up to height or do what I do.  Just 
remove some of the plastic stock from the lower portion of the 
case.  Cut a rectangle out with the bottom edge at about the 
bottom of where the old drive button was.

A little side note... these drives will step out to 83 tracks with 
no problem.  And if you have a hard drive that you boot from then 
you know how annoying it is when the drive A light stays on all 
the time.  The TEAC drive activity light turns off on its own.

There you have it. Have fun.  Course if you screw up doing this I 
will disavow any knowledge of your actions Mr. Phelps.  That's my 
disclaimer line.  You should feel quite comfortable though.  I 
have installed these drives in ALL of my machines and sold them to 
a bunch of others and have yet to have one fail (OK, I had one 
factory defect) but the rest are running like champs.

If you want to do this to your machine or have any questions feel 
free to call and I'll give you all the technical and moral support 
you need.

These babies work just as good as "B" drives too.  The drive 
jumper stays in the same place "D0".  The secret is in getting the 
wiring right and following all the pin-outs properly (FIGURE 2).  
I have done a couple of the ATARI case conversions and I wish I 
could say just plug them in or give you an easy conversion diagram 
but... time for sarcasm... ATARI is consistently inconsistent with 
their SF354 and SF315 drive layouts.

What I do is to go to my VCR shelf and rob one of the plastic 
cases from my least favorite tape (never from my porn collection, 
that is sacred) Then I cut a window out of one end with my trusty 
knife (dremel tools work, but they tend to melt plastic at high 
RPM) the size of the front of the drive... you know so the button, 
LED and all that is visible and easily operated (FIGURE 3).  Cut 
out those little round things that go in the tape wheels too.  
Make a paper template of the bottom of your drive to help you 
guess where the holes should be drilled in the VCR case to bolt it 
down (I never seem to get these right on the first try... good 
thing VCR cases are cheap).

Next I dig out one of my 6 ft. ATARI drive cables and wack that 
thing in half.  When you buy your drive you will get an adapter 
for IBM edge connectors with it.  Solder the appropriate wires to 
the appropriate connections on the edge card.  Use that diagram in 
my file for the appropriate connections (FIGURE 2).  An OHM meter 
helps this along.

You should also receive a power plug that converts the big IBM 
plug to a little plug for your drive.  Clip off the big plug.  Now 
go find a wasted ATARI mouse and cut the cord off of it.  If you 
don't have one then find a female 9 pin D-connector, about 2 ft. 
of stereo wire and wire pin 7 to the 5 volt (red) and pin 8 to the 
ground (black) of your IBM micro power plug (FIGURE 4).  (You may 
have a joystick cord that might work but check it first.  Most 
joysticks do not have pin 7 connected since most do not require 5 
volts to run.)

Now cut two slots in the back of the VCR case.  One just large 
enough for the drive cord and one just large enough for the power 
cord... oh, I forgot to tell you that was what you were making in 
the previous paragraph.  Get a bunch of you favorite elastics and 
wrap them around your power and drive cords at a point just inside 
the VCR case.  This will make a collar so the cords won't jerk out 
of the case if somebody (rug rat kids) pulls on them.

Now plug the drive plug into your outboard computer plug and the 
D-connector into your joystick port and test the drive.  Hopefully 
everything works.  If it does just squirt a little hot glue on the 
top of the drive and close the lid.  This will hold the lid shut, 
but it isn't so permanent that you can't get back in if you need 
to.

This works great for my STACY and it eliminates the extra power 
pack.  If you don't like using up a joystick port I have tapped 
connectors from the ST power supply direct to a plug which I mount 
on the back of the 1040 computer... still better than an extra 
power pack.

I did do one 1040 where I piggy backed two of these drives in.  It 
worked (thank you Lord) but it wasn't as fun as I thought in would 
be.  I recommend it only for sado-masochist.

If you mount one of these in an SF314 or SF354 the next best thing 
to do is to cut all traces from the in-bound plug on the drive's 
power/logic board.  The TEAC will not use any of ATARI's pre-drive 
circuitry.  It will just screw it up.  Now jump the appropriate 
connections to the header plug on the logic board (the header plug 
should also be isolated from ATARI's logic board.  Then make sure 
ATARI's power plug is correct.  Remember, 12 volts will kill a 
TEAC.

I wished I could be more specific about the ATARI external 
conversion, but I've seen so many different boards in them I'd 
have to write a dozen different schematics.  I've done several and 
they take longer that the first method I told you about.  However 
if you feel uncomfortable about trying one I would be glad to do 
it for you for $20.00 including the shipping.  Just send the 
board, not the whole drive.

Hope this helps a little.  Have fun with it.

Brad Bradley
Box 20
Manti, Utah  84642
(801)835-8441
Email:  BBRADLEY

PS:  If you put one of these in and it works, well, if you want to 
chip $5.00 for the info I won't be offended.  This is for you to 
enjoy your ATARI as much as possible.