Ian Stedman's Floppy Adapter

[ajack]

Hi all,

I bought an adapter from Ian a few months ago. His page is at:

URL http://www.ianstedman.co.uk/Amiga/de...daptor_v2.html

I tried using it with some drives I had and they didn't work. I get errors when attempting to format the disks. Ian was gracious enough to send me another unit thinking the earlier unit was faulty. I still had problems with the 8 floppy drives I had on me and just yesterday, I saw a store selling brand new Samsung drives and bought two units.

Again, I have problems formatting brand new diskettes which I purchased at the same time. Can anybody help me?

Some additional information. The new drives I purchased were Samsung SFD-321B rev T5. I tried Ian's adapter on an Amiga A500 rev6A with KS 3.1 ROMS. The same unit has Kipper2k's A508ide kit and a 4GB CF card installed. Uses an MC68010 processor.

This thing is driving me crazy...

[Arnie]

Can you format old disks O.K? I bought 20 "brand new" DD floppies and only 8 would format.
The others had various problems with track 0-79.

[DDNI]

Did you try your A500 in a stock config? (68000, no add on cards)
Can you try it on another Amiga?

[ajack]

I tried it on a stock A1200 as well, no dice...

[JimDrew]

I don't see anything in that schematic that handles the WRData or WREnable. What happens when you attempt to format a disk? Can you write a file to a disk that has already been formatted?

[ajack]

I got error messages when attempting to format disk

[JimDrew]

What is the error message? Can you write to a disk that has already been formatted?

[bdb]

And are they HD or DD disks?

[alenppc]

New Samsung drives have the DD detection circuit physically removed from the board, hence they are hard wired to assume that every disk inserted is a HD disk. They are unable to write or format any DD disks but they will read them. I wrote about that in the 'Modifying PC drives' thread. You should look for a better floppy drive.

[ajack]

Originally Posted by JimDrew

What is the error message? Can you write to a disk that has already been formatted?

I will try that when I get home... in the office now...

[Supamax]

Originally Posted by alenppc

New Samsung drives have the DD detection circuit physically removed from the board, hence they are hard wired to assume that every disk inserted is a HD disk. They are unable to write or format any DD disks but they will read them. I wrote about that in the 'Modifying PC drives' thread.

Arrrgh!!!
Time passes and things get worse...

Could they be modified to assume that every inserted disk is a DD disk?

[ajack]

An update, putting in a known good copy of "State of the art" demo into the Samsung drive with Ian's adapter and still no joy...

[prowler]

I've had no trouble at all getting Stedy's PC floppy drive to Amiga adapters working with lots of different floppy drives.

I would say that your 'new' Samsung floppy drives are the culprits (see alenppc's post above).

And in that case, the suggestion Supamax makes above is surely worth investigating.

[alenppc]

I also wondered how to modify Samsungs to assume it's always a DD disk, but without datasheets/schematics for the drive controller chip/PCB, it's hard to figure out.

[ajack]

Originally Posted by prowler

I've had no trouble at all getting Stedy's PC floppy drive to Amiga adapters working with lots of different floppy drives.

I would say that your 'new' Samsung floppy drives are the culprits (see alenppc's post above).

And in that case, the suggestion Supamax makes above is surely worth investigating.

I tried a while bunch of floppy drives and the results are the same...

[Arnie]

Try a different floppy cable? Is the power supply O.K? good 5v, ground?

[ajack]

Originally Posted by Arnie

Try a different floppy cable? Is the power supply O.K? good 5v, ground?

Putting in the original Chinon drive works nicely... I tested on the two spare A500 boards I have, same thing...

Originally Posted by prowler

I've had no trouble at all getting Stedy's PC floppy drive to Amiga adapters working with lots of different floppy drives.

I would say that your 'new' Samsung floppy drives are the culprits (see alenppc's post above).

And in that case, the suggestion Supamax makes above is surely worth investigating.

Prowler, what Amiga did you use, was it an A500? I tested these on A500 rev 6A (PAL) boards, I have 3 boards...

[Stedy]

Hi,

what have you changed since the 10th July when you emailed me to say that the adaptors were working perfectly?

Do you have an Escom A1200?

Are you 100% certain you did not damage anything else when you fired the two CIAs in your A500?

Ian

[prowler]

Originally Posted by ajack

Prowler, what Amiga did you use, was it an A500? I tested these on A500 rev 6A (PAL) boards, I have 3 boards...

I have used my adapters with A1200s only; both Commodore and Escom models.

But there is absolutely no reason at all why they should not work with one of my A500s, as the floppy interface is 100% comptabile. It's just that I've never had a reason to use them with an A500.

[ajack]

Originally Posted by Stedy

Hi,

what have you changed since the 10th July when you emailed me to say that the adaptors were working perfectly?

Do you have an Escom A1200?

Are you 100% certain you did not damage anything else when you fired the two CIAs in your A500?

Ian

Hi Stedy,

When I ordered the adapter from you. The first unit didn't work. The second unit work in the sense that the drive light blinked and lit as expected and when in Workbench, the usual clicking sound from an Amiga drive was clearly heard.

I tried the adapter with the few drives I had and they all gave me errors. I attributed that to perhaps the drive being old and may all have been faulty. I said they worked as the somewhat did (see earlier paragraph) and I assumed your adapter was working fine and I just needed a proper working drive to get everything going. Plus, you had sent me a replacement I assumed your device was good and blamed the old drives I had.

When I purchased the two new floppy drives, was told it's NOS stock, I had expected everything to work and now I find that the drives still don't work and thus me asking the community and not you. I am still making the assumption the second adapter you sent me works correctly.

Now I read that the Samsung doesn't do DD mode and the people testing your adapter used an A1200 (not sure if this is related to my problem).

To recap, I used an A500 rev6A board (I have three motherboards, all PAL rev6A) and tested them on all three so I assume the board where I fried the CIA chip is not a variable (was replaced BTW and floppy uses the Paula chip, no?). At this moment, I still think it's a floppy drive problem and not your adapter.

Sorry if this post had offended you or implied your adapter is not working. To be honest I do not know thus asking the knowledgeable crowd here.