Fitting of a 34 pin standard FDD socket to an Atari ST
Posted: Sun Aug 27, 2017 11:27 am
Hello all
Having been getting along well with the a number of upgrades to my STE, I was constantly finding that the floppy connector/cable was a pain, flapping around as I moved the mainboard to and fro.
So I decided to go ahead and replace the fitted IDC connector with a socket and cable from a standard PC.
Here's an old PC mainboard, ready for removal of FDD socket, the white one in the foreground. Tools used were a temperature controlled soldering iron, liquid flux, 1.5mm solder wick, small forceps, small side cutters, large illuminated magnifier and bravery! Don't worry, the PC was dead
First I prised the plastic part of the socket off carefully to avoid damage.
With the plastic part removed, I was ready to remove the pins, now easily visible.
Using the soldering iron at about 360 degrees C I heated each pin until it could be pulled out with the forceps.Half the pins are out in this shot.
With all of the pins in a small receptacle for safe keeping, plug a foppy cable into the pin less socket. Now push the pins in from the bottom until they stop in the plug, leaving just about 3 or 4 mm proud, that will push into the STE mainboard. Remove the plug from the socket when done.
The fully reassembled socket. You could probably buy one online, I chose this method as I had a sacrificial PC.
To remove the top clip on the ST FDD plug, push a small screwdriver into the end and lever. Do this at both ends. Don't worry if it breaks, you won't need it again!
Heres the top clip removed.
Now simply peel off the old cable.
Ready to remove. Start activating bravery here!!
I also marked the end where the stripe was for reference, but in a normal ST, the stripe will be towards the front. Bravery to level 2.
Bravery should now be at level 3. TAKE YOUR TIME ON THIS PART. Using side cutters, clip away as much of the plastic as you can. Be VERY careful to not damage the tracks on the mainboard. I'd suggest putting a layer or two of tape around the old socket to protect the board. Slowly and carefully chip the plastic away using the side cutters. As each pin is revealed, use the soldering iron to heat it until the pin becomes loose, and using the forceps (Or small pliers if you prefer), pull it from the board. If you encounter any resistance, stop, it is essential you don't damage the vias. Allow to cool, then reheat to avoid too much heat in one spot, and try again. For me, this was more difficult than removing the PLCC socket for the booster!!
Once completed, I used solder wick dipped in flux to desolder the holes. I was halfway done desoldering at this point.
With the holes cleared, I checked to ensure there were no solder bridges as a result of the desoldering, and inserted the socket with the keyway facing towards the right of the STE. Check all the pins protrude about 1-1.5mm on the reverse side and solder in place. Bravery can now be set to normal levels.
Lastly, I took the floppy cable, also from the old PC, and cut it to remove the 5 1/4" drive connector, and the connector the other side of the twist.
The cable after cutting. This left me with two 3 1/2" connectors on an untwisted 8" length of ribbon cable. One connector had a key, one did not. The cable I used is to the left.
Here we can see the keyless connector. The red wire represents pin 1, which we marked earlier. In the background is the socket awaiting the cable.
Cable plugged in, red wire to the front of the machine. Because this connector is keyless, it is reversible if you intend to fit a 1.44Mb floppy mod and need to twist the cable.
In case for any reason in the future there's any problem with the images, here's the original facebook post:
https://www.facebook.com/photo.php?fbid ... =3&theater
I hope this is of use to all those of you out there are looking for mods to enhance your ST/STe.
If you do decide to attempt this, don't rush, as the connector is a sod to remove. I've done this successfully, and I hope you will too, but as with any complex task on 20+ year old PCBs, there is always the risk of damage, so attempt at your own risk.
Having been getting along well with the a number of upgrades to my STE, I was constantly finding that the floppy connector/cable was a pain, flapping around as I moved the mainboard to and fro.
So I decided to go ahead and replace the fitted IDC connector with a socket and cable from a standard PC.
Here's an old PC mainboard, ready for removal of FDD socket, the white one in the foreground. Tools used were a temperature controlled soldering iron, liquid flux, 1.5mm solder wick, small forceps, small side cutters, large illuminated magnifier and bravery! Don't worry, the PC was dead
- donor.jpg (274.89 KiB) Viewed 10220 times
First I prised the plastic part of the socket off carefully to avoid damage.
- donor2.jpg (151.72 KiB) Viewed 10220 times
With the plastic part removed, I was ready to remove the pins, now easily visible.
- donor3.jpg (215.27 KiB) Viewed 10220 times
Using the soldering iron at about 360 degrees C I heated each pin until it could be pulled out with the forceps.Half the pins are out in this shot.
- donor4.jpg (244.8 KiB) Viewed 10220 times
With all of the pins in a small receptacle for safe keeping, plug a foppy cable into the pin less socket. Now push the pins in from the bottom until they stop in the plug, leaving just about 3 or 4 mm proud, that will push into the STE mainboard. Remove the plug from the socket when done.
- socket.jpg (134.83 KiB) Viewed 10220 times
The fully reassembled socket. You could probably buy one online, I chose this method as I had a sacrificial PC.
- socketready.jpg (64.17 KiB) Viewed 10220 times
To remove the top clip on the ST FDD plug, push a small screwdriver into the end and lever. Do this at both ends. Don't worry if it breaks, you won't need it again!
- clipoff.jpg (301.13 KiB) Viewed 10220 times
Heres the top clip removed.
- clipoff2.jpg (341.54 KiB) Viewed 10220 times
Now simply peel off the old cable.
- peel.jpg (360.37 KiB) Viewed 10220 times
Ready to remove. Start activating bravery here!!
- ready.jpg (374.07 KiB) Viewed 10220 times
I also marked the end where the stripe was for reference, but in a normal ST, the stripe will be towards the front. Bravery to level 2.
- mark.jpg (373.59 KiB) Viewed 10220 times
Bravery should now be at level 3. TAKE YOUR TIME ON THIS PART. Using side cutters, clip away as much of the plastic as you can. Be VERY careful to not damage the tracks on the mainboard. I'd suggest putting a layer or two of tape around the old socket to protect the board. Slowly and carefully chip the plastic away using the side cutters. As each pin is revealed, use the soldering iron to heat it until the pin becomes loose, and using the forceps (Or small pliers if you prefer), pull it from the board. If you encounter any resistance, stop, it is essential you don't damage the vias. Allow to cool, then reheat to avoid too much heat in one spot, and try again. For me, this was more difficult than removing the PLCC socket for the booster!!
- remove.jpg (141.35 KiB) Viewed 10220 times
Once completed, I used solder wick dipped in flux to desolder the holes. I was halfway done desoldering at this point.
- desoldering.jpg (155.84 KiB) Viewed 10220 times
With the holes cleared, I checked to ensure there were no solder bridges as a result of the desoldering, and inserted the socket with the keyway facing towards the right of the STE. Check all the pins protrude about 1-1.5mm on the reverse side and solder in place. Bravery can now be set to normal levels.
- fitted.jpg (135.72 KiB) Viewed 10220 times
Lastly, I took the floppy cable, also from the old PC, and cut it to remove the 5 1/4" drive connector, and the connector the other side of the twist.
- cable.jpg (237.75 KiB) Viewed 10220 times
The cable after cutting. This left me with two 3 1/2" connectors on an untwisted 8" length of ribbon cable. One connector had a key, one did not. The cable I used is to the left.
- cable1.jpg (246.16 KiB) Viewed 10220 times
Here we can see the keyless connector. The red wire represents pin 1, which we marked earlier. In the background is the socket awaiting the cable.
- nearlythere.jpg (206.68 KiB) Viewed 10220 times
Cable plugged in, red wire to the front of the machine. Because this connector is keyless, it is reversible if you intend to fit a 1.44Mb floppy mod and need to twist the cable.
- done.jpg (323.05 KiB) Viewed 10220 times
In case for any reason in the future there's any problem with the images, here's the original facebook post:
https://www.facebook.com/photo.php?fbid ... =3&theater
I hope this is of use to all those of you out there are looking for mods to enhance your ST/STe.
If you do decide to attempt this, don't rush, as the connector is a sod to remove. I've done this successfully, and I hope you will too, but as with any complex task on 20+ year old PCBs, there is always the risk of damage, so attempt at your own risk.
