Using an internal Gotek and an external disk drive

[sandord]

I've got an internal Gotek installed in my STE as a replacement for the original disk drive and it works great.

Today I wanted to write to a real floppy disk so I thought I'd connect my external disk drive (SF314).

But so it seems, the Gotek hijacks the signal and completely leaves the external drive in the void.

I've come to understand that this may have something to do with the fact that the ST has only one Motor-On signal for both drives and the Gotek doesn't know about this peculiar (non-standard) fact and therefore responds to the B drive request as well.

Mind you, I'm not interested in booting from the external drive and I also don't mind not being able to use both at the time. The latter is because I have an UltraSatan so I can copy files from my SD card to the external drive. I just want to be able to write files to a floppy disk :)

Now I've been thinking to install a switch that optionally interrupts the Montor-On signal to the Gotek, so that the external drive can behave like normal. Would this be enough or do I need to block more signals for the Gotek to get out of the way?

[exxos]

It be pretty bad design if gotek was only responding to MON signal. Drives shouldn't care about it and be using the drive select signals to select A or B.

Lookin at some images there's a load of jumpers?


https://lepszyserwis.pl/wp-content/uplo ... matics.png

[rubber_jonnie]

I've got an internal Gotek installed in my STE as a replacement for the original disk drive and it works great.

Today I wanted to write to a real floppy disk so I thought I'd connect my external disk drive (SF314).

But so it seems, the Gotek hijacks the signal and completely leaves the external drive in the void.

I've come to understand that this may have something to do with the fact that the ST has only one Motor-On signal for both drives and the Gotek doesn't know about this peculiar (non-standard) fact and therefore responds to the B drive request as well.

Mind you, I'm not interested in booting from the external drive and I also don't mind not being able to use both at the time. The latter is because I have an UltraSatan so I can copy files from my SD card to the external drive. I just want to be able to write files to a floppy disk :)

Now I've been thinking to install a switch that optionally interrupts the Montor-On signal to the Gotek, so that the external drive can behave like normal. Would this be enough or do I need to block more signals for the Gotek to get out of the way?

I'd check your Gotek jumpers, all that should be installed is the S0 jumper and nothing else.

I've done exactly this with an internal Gotek with just S0 installed and an external floppy (It wasn't an SF314, but it shouldn't matter) and had no issues at all.

I've also done it the other way around with an external Gotek and internal floppy, no issues at all.

[sandord]

Thanks guys.

It's great to know that it should normally just work.

The only jumper that is set on my Gotek is M0 so that shouldn't be the problem (Al my Goteks are configured this way).

Further testing showed that when I place a normal floppy drive inside the machine (STE), the external drive still doesn't work.

When I connect the external drive to my other STE, which also has a Gotek, the external drive does also does not work.

But when I connect the external drive to an ST that has no Gotek (just the standard floppy drive), the external drive DOES work.

I also have an ST with a Gotek installed. When I get home, I'll try that one as well.

I'm still a bit confused as it seems that the STE itself might be a problem since the drive doesn't work even without a Gotek in play.

Isn't it nice when multiple issues start muddling the pool :o

[rubber_jonnie]

Thanks guys.

It's great to know that it should normally just work.

The only jumper that is set on my Gotek is M0 so that shouldn't be the problem (Al my Goteks are configured this way).

Further testing showed that when I place a normal floppy drive inside the machine (STE), the external drive still doesn't work.

When I connect the external drive to my other STE, which also has a Gotek, the external drive does also does not work.

But when I connect the external drive to an ST that has no Gotek (just the standard floppy drive), the external drive DOES work.

I also have an ST with a Gotek installed. When I get home, I'll try that one as well.

I'm still a bit confused as it seems that the STE itself might be a problem since the drive doesn't work even without a Gotek in play.

Isn't it nice when multiple issues start muddling the pool :o

M0 is incorrect it should be S0 only for the ST. M is for Motor S is for drive ID.

[sandord]

Oh god, I meant to say S0. Sorry for the confusion!

I'm not at home at the moment so I had to (tried to) do it from memory.

[rubber_jonnie]

Oh god, I meant to say S0. Sorry for the confusion!

I'm not at home at the moment so I had to (tried to) do it from memory.

No worries.

[sandord]

I've done some more extensive testing and here is my report.

• All machines have recapped PSUs in them (Exxos kit)
• Testing with a floppy that was freshly formatted in an ST.
• External FDD was always plugged into the machine before turning it on
• All Goteks have only the S0 jumper crossed.

STE 1 (has DMA fix)

Internal FDD only:

• Internal FDD works fine

Internal FDD + external FDD:

• Internal FDD works fine
• External FDD: TOS says "Please insert disk B intro drive A:" when attempting to access it. I do hear the FDD motor spinning while the internal FDD is accessed though but the light on the external drive never lights up.

Internal Gotek + extern FDD: (Gotek has HxC firmware)

• Internal Gotek works fine
• External FDD: TOS says "Please insert disk B intro drive A:" when attempting to access it. I do hear the FDD motor spinning while the internal FDD is accessed though but the light on the external drive never lights up.

STE 2

Internal Gotek only:

• Internal Gotek works fine

Internal Gotek + external FDD:

• Internal Gotek works fine
• External FDD: TOS says "Please insert disk B intro drive A:" when attempting to access it. I do hear the FDD motor spinning while the internal FDD is accessed though but the light on the external drive never lights up.

STF 1

Internal Gotek + External FDD:

• Internal Gotek works fine
• External FDD: TOS says "Please insert disk B intro drive A:" when attempting to access it. I do hear the FDD motor spinning while the internal FDD is accessed though but the light on the external drive never lights up.

STF 2

Internal FDD only:

• Internal FDD works fine

Internal FDD + external FDD:

• Internal FDD works fine
• External FDD works fine
• Can copy files across drives successfully

Screenshot 2025-05-25 125638.png

As you can see, there's only one machine where my external FDD works and it is both a non-STE and has no Gotek. I still wonder which of those two factors (or both?) is the culprit and more importantly: how?

[exxos]

I think you need to check the Drive select signals which I think come from the YM chip.

[DoG]

Check cable?