How to modify a Sony MPF 920 to provide a ready signal

[gerald]

Bryce, your memory is fading away 
We talked about this drive one year ago : Thinking of buying this 3/1/2 inch drive

And the solution you propose will not work on a CPC 

[Guy0me]

Bryce, your memory is fading away 
We talked about this drive one year ago : Thinking of buying this 3/1/2 inch drive

And the solution you propose will not work on a CPC 

Gerald you find me lol , I asked on this forum just to be sure but i trusted you. 

[Bryce]

Bryce, your memory is fading away 
We talked about this drive one year ago : Thinking of buying this 3/1/2 inch drive

And the solution you propose will not work on a CPC 

Really??? I really am getting old then! No memory of that. Did we find out why it doesn't work? Brain-fade......

Bryce.

Edit: Ok, read the thread. So you'd need to add some sort of latch to get it to work properly. Pity.
In my defence, that thread is over a year old! You don't expect my weary old brain to store thread details from that far back! I can just barely remember what I had for breakfast this morning!

[Subaru]

Ca ressemble a de l'amiga mod, mais la soluce est comme la vérité. (ailleurs...)

-_-

[Bryce]

Yes, it is very similar to the Amiga mod, but the Amiga Shugart also isn't to the standard and expects different signals to the CPC.

Bryce.

[Lazy Dude]

don't think the wiki has been updated to include the sony FDD yet.
Or did I miss it, hmm must look again, again...

[Lazy Dude]

I have a solution to obtaining the disk ready status!
cut track to pin 34, locate HD switch and cut both tracks (this function is not needed, so just bridge the tracks to make the drive permanently  stay in low density state)
now we have an available disk detect switch!
solder 2 wires from the switch to pins 33 & 34.
done!

well thats my thoughts and I will be busting out the tools to check it works later on 

[CraigsBar]

I have a solution to obtaining the disk ready status!
cut track to pin 34, locate HD switch and cut both tracks (this function is not needed, so just bridge the tracks to make the drive permanently  stay in low density state)
now we have an available disk detect switch!
solder 2 wires from the switch to pins 33 & 34.
done!

well thats my thoughts and I will be busting out the tools to check it works later on 

I tried that some time ago on a drive. It did not work..... But the drive in question was of questionable quality anyway. Lol.

[dxs]

Look at this page (have it translated by google):


http://quasar.cpcscene.net/doku.php?id=electronique:lecteur_3.5&s


About 1/3 down is a small circuit with a transistor and a few logic gates which will provide a clean ready signal, only when the proper drive is selected, using the disc-in switch if your drive has one or the density detection switch (which you don't need anymore).
I remember building my 3 1/2 with this circuit, it's perfectly working. I could dig it out and open it if needed.

[Piotr]

Here is my mod Sony for DDI Clone

DDI floppy mod

[TFM]

What does it do? Does it switch Ready constantly to on or does make a true Ready signal?

[Bryce]

It would give a Ready signal when a disk is physically in the drive.

Bryce.

[gerald]

Even when the drive is not selected ...

[Bryce]

Yes, that's the problem. The schematic on the French site linked above is a much cleaner solution.

Bryce.

[gerald]

Yes, that's the problem. The schematic on the French site linked above is a much cleaner solution.

Yes, I've discovered this.
That's roughly what I've done on my own MPF920. I am using smd single gate for the or and a tristate driver instead of the transistor. And also, I use a spindle motor controller as ready information.

[dxs]

Cleanest solution possible.
Even if less "perfect" HD/SD switch solution is working fine as input to the gate , though.
When you put your drive in a clean box (external CDROM burner or whatever) you have all room to include a small perfboard with the few components on it.

[Grim]

/Drive Select 1 -> [HD/SD Switch] -> Diode -> /Ready
No gates required, just cutting some tracks, one diode, two wires and that's it.

Edit: can't remember which diode model I used, but it was nothing fancy.

[TFM]

/Drive Select 1 -> [HD/SD Switch] -> Diode -> /Ready
No gates required, just cutting some tracks, one diode, two wires and that's it.

Wouldn't Ready be there immediately after you select the drive?

If yes, then this is problematic since the drive may not be ready for some more milliseconds. Then we have the problem.

[Grim]

Dunno, there might be some quirks, but I've been using 3.5 drives modded that way for nearly a decade without noticing any particular problem (eg. Orion Prime, Batman Forever, Phortem and other stuffs with exotic loaders all work fine).

[TFM]

Check Symbos or FutureOS 

[gerald]

Wouldn't Ready be there immediately after you select the drive?

No, it will only pull ready low when the drive is selected and the switch is closed (and the diode polarized the right way  , anode on the ready side).

[TFM]

But is the drive already spinning quick enough, to be "Ready" for a data transfer?


FutureOS for example does not wait a defined time to start reading, it just waits for the drive being ready. That principle was later adopted for SymbOS too. I hope I made my self clear at which point I'm driving. If the Ready signal is there a bit before the drive is really ready, then there is a problem.

[gerald]

But is the drive already spinning quick enough, to be "Ready" for a data transfer?

Who knows 

FutureOS for example does not wait a defined time to start reading, it just waits for the drive being ready. That principle was later adopted for SymbOS too. I hope I made my self clear at which point I'm driving. If the Ready signal is there a bit before the drive is really ready, then there is a problem.

I'm on your side !

[Bryce]

Add a fat capacitor and another diode to delay the ready signal.

Bryce.

[Grim]

Or handle the FDC error properly :)