Issues Connecting 3.5" floppy to 6128

[Bryce]

Hi Ray, I'm already using the 33-34 jumper on the floppy cable as per the wiki. I really want to get a true ready signal. Call me a perfectionist 

I've ordered a Rom board from Toto so I'll be running Parados on it when It arrives. I prefer to keep my boxes original, so I don't want to replace the AMSDOS rom in my 6128. I have put Parados on my DDI-1 as the ROM was socketed, but I'm still working out the cabling to get the 3.5" on there. I note in @Bryce 's wiki page that an FD1 cannot be used at the same time as a 3.5" drive. I'm hoping that if I make a modified cable for the DDI-1, do the mod to power it from the CPC and disconnect the power supply jumper from within the FD1, I might be able to swing that.

Or maybe I just get another 6128 to mod so I can have best of both worlds.... Decisions Decisions 

Wayne.

That's not quite correct. I really need to clarify that page because it's confusing. You can connect a 3.5 and FD-1 at the same time, however, only with the 3in as A: and the 3.5in as B:. My mod allows you to use a 3.5in drive as A:, but then you can't connect a 3in drive.
(Does that make sense??)

Bryce.

[opticpow]

That's not quite correct. I really need to clarify that page because it's confusing. You can connect a 3.5 and FD-1 at the same time, however, only with the 3in as A: and the 3.5in as B:. My mod allows you to use a 3.5in drive as A:, but then you can't connect a 3in drive.
(Does that make sense??)

Bryce.

Ah ok, that's cool, I'm only wanting to use the 3.5" as B at this stage.

Wayne.

[Bryce]

Then you don't need to mod anything, just connect the FD-1 to the connector at the end of the flat cable and the 3.5in drive to the connector nearest the DDI-1.

Bryce.

[TFM]

It looks like he is using the Disk change switch to set pin 34 ?

Yes, it looks like. And the problem is, that this doesn't work with write protected discs. (And it's not delayed enough).

[opticpow]

Then you don't need to mod anything, just connect the FD-1 to the connector at the end of the flat cable and the 3.5in drive to the connector nearest the DDI-1.

Bryce.

Thanks Bryce, that's good to know. I've gone the long way around to discovering that I can just plug it in as is  (baring the stupid almost but not quite standard 34 way IDC connector. Thanks Amstrad  )

Edit: Do I not need to worry about the +5v supply on some on the ground connectors?

[Audronic]

Hi Wayne


For an external drive 1 (B) added to a  6128
The cable that i use is just a straight 34 Pin cable wired 1-1 34-34 connected to an external floppy configured as drive 1 (B).
Power is provided in my case from an old PC power supply.


Good luck      Ray

[Bryce]

Thanks Bryce, that's good to know. I've gone the long way around to discovering that I can just plug it in as is  (baring the stupid almost but not quite standard 34 way IDC connector. Thanks Amstrad  )

Edit: Do I not need to worry about the +5v supply on some on the ground connectors?

The IDC connector nearest the DDI-1 has these pins removed so that the 5V from the FD-1 only goes to the DDI-1.

Bryce.

[CraigsBar]

OK. So the Samsung SFD 321b has just become my favourite all round floppy.

Just modded one for combination use with a JustCPC 128k and a bare board a600. Mods as follows mean it is now 100% compatible with both boards....

1. Move the 0 ohm resistor from DC to RDY as before.
2. Remove the DS1 solder blob, and create the DS0 one.

This is now a CPC A: drive, all good. But the Amiga expects DC on pin 2 so....

3. Add a jumper wire between the DC point that is *not* connected to pin 34 and pin 2.

All done? You now have a CPC/Amiga A:/DF0 drive that can be swapped between systems as needed.

Thank you Samsung for the nice modable PCB on these drives.

[Audronic]

@CraigsBar
Well done.
Do you have a photo of the finished Board.
Thanks   Ray

[CraigsBar]

It's recased at the moment. I'll strip it and photograph it tomorrow, OK?

[Audronic]

@CraigsBar

To save you uncasing .

Edit:-   Solved.  Top Connection.


Ray

[CraigsBar]

@CraigsBar

To save you uncasing .

Edit:-   Solved.  Top Connection.


Ray

Yep, top one

It works a treat

[Audronic]

@CraigsBar
I was just looking at the Manual for the drive and PIN2
? Did you remove The "" OPA "" Link on the Board ? ?

Link to Manual:-
oem manual sfd-321b - techtravels.org

Link to an Other Modification for Amiga

http://jope.fi/drives/sfd321b/
-====================--

5.3.1 Density Select
This siganl is used to distinguish between 1.6MB and 2MB Mode.
The interface pin No.2 can be used as Density Select Input signal by attaching 0 Ω resistor onto "OPA" short plug when the High density media is inserted. The "HIGH" level designates 2MB Mode and the "LOW" level designates 1.6MB Mode. FDD can tell whether the inserted media is high or Low density by checking the signal coming from mechanical switch which detects the density selecting hole on the media.

2 Mode
(2.0 / 1.0MB) (Non-connection of "OPA")

Automatic Switching
2.0MB : If High density media is inserted. 1.0MB : If Low density media is inserted.
      

3 Mode (2.0 / 1.6 / 1.0MB) (Connection of "OPA") Automatic Switching with "Density Select" 2.0MB : If High density media is inserted with "Density Select" is "HIGH". 1.6MB : If High density media is inserted with "Density Select" is "LOW". 1.0MB : If Low density media is inserted "Density Select" is not available. Ray

[CraigsBar]

Fortunately all the SFD 321b drives I have modded so far have had a density sensor still in place so as long as I use 720k discs (or cover the hole) the the drive works on the amiga with just these 3 mods

[Audronic]

@CraigsBar


Thanks


Ray

[Audronic]

Sony MPF920 Floppy Drive Update 25-09-2016


For an Amstrad CPC series machine

This mod works with CPM (Eject Disks)
Correct operation of the Ready signal on Pin 34

Ray