exxos's Atari, Amiga & retro forum

Hello
I use a Atari Mega ST 1 with Heron 4MB Ram and want to install the 1,44 floppy mod
Board Nr 103277 Rev 2.2

But this 1,44 floppy board is not running
With the board they don't show any fdd drive A or B icon on the desktop
Only hdd is shown

Normal ,without the 1,44 floppy board, all is running with 720kb

I put the wire from floppy Board P1 to Mainboard W1 Pin1 and floppy Board P2 to Mainboard W1 Pin3.
Onto the Board I install the WD1772 02-02 89 and the Floppy Gal.

That's all.


Sony MPF920 Z/121:
Also I change the FDD Sony JC30 to SEL 0
What is with the red cable on the fdd. See foto



I find a missed smd 805 1KOhm resistor and put a normal 1K resistor on the place.
This I change to an smd resistor if I become a new one

thank you

But what have you done with the red floppy drive cable? Have you plugged the floppy ribbon cable upside down as its required for 1.44 drives. Nothing is connected to D0 D1 either..

Did you read the install instructions?

https://www.exxosforum.co.uk/atari/last ... /index.htm

I put it upside down in Floppy conector
Pin2 from Atari is Pin2 on floppy
The red cable from floppy where i have to make it on Floppy Board?

The Red wire at the Sony Floppy on the HD/DD switch select 720 or 1,4MB mode ...

You haven't soldered the correct motherboard pins either. It's labeled on the PCB P1 P2.. You soldered P1 P3... Its best to solder per instructions as it makes things unnecessarily complicated otherwise.

You can test 720k mode by soldering over D0 D1..

Ok tomorrow i do it
P3 auf P2

Then a solder bridge over d0 and one over d1
Is that ok?

bbisi wrote: 09 Jul 2025 19:53 Then a solder bridge over d0 and one over d1
Is that ok?

Yes, the basically makes the board "transparent" so it should work as normal with 720K (and your original drive) the 1.44 can also work, but only with 720K.

Yes I do it, but nothing happens
See the fotos
Soldering bridge d1
Soldering bridge d0
W1 brown cable from pad 3 to pad 2

Well you shouldn't have the red wire soldered to the floppy drive AND D0,D1 soldered at the same time..

But really you should be working.. Either you have a bad connection somewhere, maybe on the 1772 or floppy cable or your drive isn't working, or you have cable upside down or something like that. Normally no drives on desktop is cable plugged in wrong, (the floppy light stays on all the time) Did you check ?

Does the drive you are using work without the 1.44 module ?

Hi


I cut the red wire. Only the two wires to W1 are on the 1772 board at P1 and p2.
Also the soldering bridges DS0 + DS1

Either you have a bad connection somewhere, maybe on the 1772. - I test it today. I think so
Floppy cable or your drive is ok. - Without the 1,44 floppy board it is running with the old 720 and 1,44 er floppy
You have cable upside down . No the cable is correct P1 red marked is Floppy Pin 1

Normally no drives on desktop is cable plugged in wrong, (the floppy light stays on all the time) Did you check ? It is not always on

Does the drive you are using work without the 1.44 module ? - Yes the 720kb original drive is running. The 1,44 Sony MPF920 is also running in 720kb mode

I order a new 1,44 board with gal. Then we see