Floppy header pinout - loose pin

Problems with your machine in general.
spiny
Posts: 25
Joined: Tue Aug 22, 2017 5:29 pm
Location: Bristol, UK
Contact:

Floppy header pinout - loose pin

Post by spiny » Wed Aug 23, 2017 8:35 am

Hi Guys,

I'm working on one of my FMs and while I was checking it over last night I noticed that on the floppy header I added a few years back, there is a loose pin. it has been pushed through the board a little and on closer investigation, I can push and pull it through the board with tweezers.

It -appears- to be pin 16 'motor b enable'

is this a pin thats actually used on the ST ? there doesn't seem to be a solder pad or trace running to on the bottom of the board, but I'd like to know if it's going to stop the drive a working before I start cutting chips off :)

will grab some pics this evening.

cheers :)

User avatar
exxos
Site Admin
Site Admin
Posts: 4048
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Floppy header pinout - loose pin

Post by exxos » Wed Aug 23, 2017 9:20 am

spiny wrote:
Wed Aug 23, 2017 8:35 am

is this a pin thats actually used on the ST ? there doesn't seem to be a solder pad or trace running to on the bottom of the board, but I'd like to know if it's going to stop the drive a working before I start cutting chips off :)
"Motor On" is exactly that. It turns the floppy drive motor on (makes the floppy spin).

I actually use that signal on my V6 floppy kit as some AND type logic to enable 16mhz mode.

The copper track may well be on the top of the board. Resoldering likely going to be a issue if it is under plastic. Assuming the via is not damaged, you could try placing some flux on the pin and trying to resolder it, see if the solder will "suck" back into the hole and solder the pin back.

Either that , or see if you can remove the plastic and resolder from the top. If the track is damaged, then you will have to solder a wire to the pin to reconnect the motor on signal.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

spiny
Posts: 25
Joined: Tue Aug 22, 2017 5:29 pm
Location: Bristol, UK
Contact:

Re: Floppy header pinout - loose pin

Post by spiny » Wed Aug 23, 2017 10:13 am

bums.

I'll try a careful re-flow from underneath first.

still, the more I solder, hopefully the better I will get :)

User avatar
exxos
Site Admin
Site Admin
Posts: 4048
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Floppy header pinout - loose pin

Post by exxos » Wed Aug 23, 2017 10:16 am

spiny wrote:
Wed Aug 23, 2017 10:13 am
bums.

I'll try a careful re-flow from underneath first.

still, the more I solder, hopefully the better I will get :)
At least you are trying, which is more than can be said for a lot of people :)

Let us know how you get on :)
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

spiny
Posts: 25
Joined: Tue Aug 22, 2017 5:29 pm
Location: Bristol, UK
Contact:

Re: Floppy header pinout - loose pin

Post by spiny » Wed Aug 23, 2017 11:36 am

but just to confirm, pin 16 is motor B enable, not motor A (pin 10 seems to be motor A) , so will having it N/C just mean that if I connect a Dribe B, it won't spin up ? if thats the case, i'll leave it as it is, rather than potentially screw it all up even more.

User avatar
exxos
Site Admin
Site Admin
Posts: 4048
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Floppy header pinout - loose pin

Post by exxos » Wed Aug 23, 2017 12:28 pm

spiny wrote:
Wed Aug 23, 2017 11:36 am
but just to confirm, pin 16 is motor B enable, not motor A (pin 10 seems to be motor A) , so will having it N/C just mean that if I connect a Dribe B, it won't spin up ? if thats the case, i'll leave it as it is, rather than potentially screw it all up even more.
I'm not at home right now to check' but IIRC motor A&B are the same signal.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

User avatar
rpineau
Site Admin
Site Admin
Posts: 360
Joined: Thu Aug 17, 2017 6:08 pm
Location: USA
Contact:

Re: Floppy header pinout - loose pin

Post by rpineau » Wed Aug 23, 2017 5:53 pm

I took a quick look at the schematics and pin 16 is Motor On. Both the internal connector and the external floppy plug are connected to that pin on the mother board (going through a 74LS06 gate) from the FDC pin 20. So they are the same signal.
If the track is broken you might be able to run a small wire from the ferrite beads that is between the connector and the 74LS06 (U14 on the 1040 STFM schematics) pin 8. The schematics is hard to read but it looks like its the filter bead 224.
Rodolphe
Working ones : MegaSTE (68020) / TT030 / Falcon with AB040 & Eclipse / 1040STF
Need testing : Falcon with CT2

spiny
Posts: 25
Joined: Tue Aug 22, 2017 5:29 pm
Location: Bristol, UK
Contact:

Re: Floppy header pinout - loose pin

Post by spiny » Wed Aug 23, 2017 9:36 pm

pics, as promised:
2017-08-23 21.29.41.jpg
2017-08-23 21.29.41.jpg (2.97 MiB) Viewed 865 times
2017-08-23 21.30.08.jpg
2017-08-23 21.30.08.jpg (3.3 MiB) Viewed 865 times
the pin i'm pointing a scalpel at is the loose one in the top view, hopefully it's more obvious which pin it is on the bottom view :)

spiny
Posts: 25
Joined: Tue Aug 22, 2017 5:29 pm
Location: Bristol, UK
Contact:

Re: Floppy header pinout - loose pin

Post by spiny » Wed Aug 23, 2017 9:37 pm

note: the extra wire on the WD is where i've removed an old HD/DD switcher board.

User avatar
exxos
Site Admin
Site Admin
Posts: 4048
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: Floppy header pinout - loose pin

Post by exxos » Wed Aug 23, 2017 10:14 pm

Likely is PCB track running on the top. Try to resolder as I suggested, Check with a meter the connection as Rodolphe suggested. If track is broken, then you will have to wire link it back up.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

Post Reply