exxos's Atari, Amiga & retro forum

Hello,

This does somehow feel like a stupid question.
But there's no such thing as stupid questions and I couldn't find an answer by myself.

After installing the 1.44 rev 6 update kit in my Mega ST, I tested with a Scope.
If the drive is accessed, the clock to the Floppy controller is switching between 8 and 16 Mhz, depending on the disk.
And it does switch back to 8Mhz once floppy acces is done, so far so good.
The clock signal for the PCB comes from the shifter buffer board.
For the 720K use, all works fine and I can read a disk.
But the 1.44Mb doesn't seem to work.
The copy programs also don't work in 1.44 or HD mode. Format attempts result in sector errors / bad sectors.

So how do I tell TOS (1.04 or 2.06) that a 1.44Mb drive and disk are there?

BR/
Guus

TOS does not need to know about the floppy.

Its possible on the MEGA ST the 16mhz has noise causing the issues. You will likely need the mega buffer kit.

Hello,

The Mega ST buffer board is on the PCB.
As is the Mega ST V2.2 booster. And that does work stable. (Enough to rum Gembench and copy files from floppy to Ultrasatan)
This evening I'll make a picture of the setup.
And I can try a 16Mhz oscillator as clock source. But I don't like that, it's one more extra component....

BR/
Guus

guus.assmann wrote: ↑Mon Oct 09, 2017 10:48 am The Mega ST buffer board is on the PCB.
As is the Mega ST V2.2 booster. And that does work stable. (Enough to rum Gembench and copy files from floppy to Ultrasatan)
This evening I'll make a picture of the setup.
And I can try a 16Mhz oscillator as clock source. But I don't like that, it's one more extra component....

Pins 19, 20, 21, on the mega buffer PCB are all Steam megahertz outputs. So whichever one you are feeding the booster with, use a different pin on the buffer PCB. Try that, and it is still have troubles try adding a 68R resistor in series with the wire to the floppy kit.

It is also possible that your 1772 may not actually work at 16 MHz... You're welcome to send it to me to testing if it helps..

exxos wrote: ↑Mon Oct 09, 2017 1:02 pm It is also possible that your 1772 may not actually work at 16 MHz... You're welcome to send it to me to testing if it helps..

This is my guess. Is it a VL-model? (That's what my Megas have)

/Troed

troed wrote: ↑Mon Oct 09, 2017 2:11 pm This is my guess. Is it a VL-model? (That's what my Megas have)

I think I have a VL in my test machine and it works at 16MHz. Pot luck really, which ones will work faster and which ones don't.

These are the ones from my website from ages ago which were working fine.



The VL ones tend to run hotter, there were a lot of these will run at high speeds. The WD ones is also potluck, regardless if they are 00 or 02, I seem to have several chips which will run fine, then I will have several chips in various machines which do not work at higher speeds. I don't really know what the differences between all these are.

Maybe in the case of the WD ones, maybe there was two different factories producing them at the time, I never really took notice of any other numbers on the chips or batches etc. anyone's guess really

Hello,
Thanks for the suggestions. And Yes, I did try several controllers.
To make sure that they are OK, I've also had them in a Mega STE. And there they did HD just fine.
And I have tested 4 controllers in total, so it's not those.

So next I put a 16Mhz oscillator to the input of the floppy PCB.
And I tried to format a HD floppy and read it. Format did work fine now. Just not for 1,44Mb, but it did finish. (Tos 2.06 Formatting)
Also, I could read a 1,44Mb disk and start a program from that disk.
And the 720Kb just kept working of course.
So next I reconnected the Buffer output, using a thinner wire.
I can't believe it makes a difference, but now it works as well.

As promised, the pictures.
I currently have 5 Mega ST boards "in the works" and use them for tests. (Every time with an "Exxos transformer supply")
The object is to test a couple of boards and speeders.
Magnum 10MB, Compro-Tos 2.06, PP-Flash-Tos and IDE, Exxos-Toscard, Pak68-2, HBS240, AD-Speed by ICD, 68020 speeder, HBS640, Hypercache-Turbo.
All of these work in some combination. The Magnum card is sometimes a "spoilsport"
The only card I didn't get to work is the SST card. But it does give a blank screen in Hi-Res and sometimes reboots.
And I still have to test the Pak68/3.
BR/
Guus

guus.assmann wrote: ↑Mon Oct 09, 2017 8:41 pm So next I reconnected the Buffer output, using a thinner wire.
I can't believe it makes a difference, but now it works as well.

So was that your only problem then ? changed from thicker to thinner wire ?

Well, I'm not sure anymore.
There may be some other issue, later last evening it didn't work anymore.
I'll have to do some more testing later this week.

BR/
Guus

Move to another pin on the header on the buffer board as said before, and try 100R resistor in series.