Modifying PC floppy drives for Amiga use

[rkauer]

For those drives who doesn't have a disk change signal available, the most simple trick is JOIN the pin 30 with the 34!

Works like a charm with ANY floppy unit I tested so far.

[Chain]

connecting data with diskchange?

[DrF]

I saw that a demo was mentioned as a test for a modded drive, is there any other tests or advice, as I just modded a unknown/generic drive which seems to work, I kinda got it going using instructions from a few drives
It clicks like a real drive, loads Workbench & Captain Planet (Cap. P. did load, then did not, now does), waits for you to insert a disk and off it goes, can change disk in Workbench so I presume in 2+ disk games they should work.

I have not tried writing yet, but its looking good so far
Disk change was wired to pin 2
Ready was wired to pin 34
Drive is set to unit 0

The drive has a block of jumpers that are labeled (RY,DC,DS etc) but did not work correctly until I added the wires.

Edit : Alas... it now becomes clear this was not such a great idea, although it reads fine, changes disks fine, it don't seem to format right, or I guess write correctly

Oh well I got close

[Zetr0]

hmmm wasn't a there a reset ready signal ?

[DrF]

As requested by Lord Zetr0, with my crude descriptions of pin outage
The wiring on the 1st pic is the only way I could get the drive to behave like a normal Amiga drive ie. click, click, click, recognise disks change and actually read, not quite sure if its right thought.

DC was put to pin 2
Ready was put to pin 34
The drive ID jumper was put to 0

Just will not write correctly, either says "Can't find cylinder 0" or I got to format to the end of a floppy and it spat out "Can't find cylinder 79" I think it was :P

The 2nd row of jumpers don't line up with the letters for some odd reason, so they may not make any sense

The IBM part number reveals very little, all it brings up in Google is IBM 1.44Mb 3.5" floppy, I would assume its some rebranded drive and then IBM stuck a sticky on or something.

[Zetr0]

@Drf

can i have LARGER pics please

[DrF]

Originally Posted by Zetr0

@Drf

can i have LARGER pics please

Oh... he wants a bigger pair does he
Of course you can but there not super excellent, the above are just cropped vers, I'll upload a set

As you desire your Lord :

http://www.busydizzys.com/temp/100_0947.JPG
http://www.busydizzys.com/temp/100_0948.JPG

[dlfrsilver]

hey since we are in disks drives modification, is there any hardware trick
to make a drive running slower ? In order to let it write more datas per track ?
strange no one tried ?

[DrF]

Originally Posted by dlfrsilver

hey since we are in disks drives modification, is there any hardware trick
to make a drive running slower ? In order to let it write more datas per track ?
strange no one tried ?

Theres some trackdisk replacement thingy on Aminet somewhere that allows 930ish K I think on a disk, not quite what your after but I guess its close

[dlfrsilver]

was talking about hardware modif to the drive, in order for it to do 150 RPM instead of 300. This way you can write back any program you like.

This is what we lack. But the drive modif is great too

[DrF]

Originally Posted by dlfrsilver

was talking about hardware modif to the drive, in order for it to do 150 RPM instead of 300. This way you can write back any program you like.

This is what we lack. But the drive modif is great too

I thought the later Commodore HD (A4000)disk drives ran at 150Rpm anyhow?
Was they normal PC HD drives (modded) or a custom Commodore contraption?

[Jope]

They were custom made to order.

[dlfrsilver]

maybe asking to IFW or someone with hardware knowledge .....

[Jope]

There are schematics and info regarding the 150rpm modification on Aminet.

The modified drives are told to be very unstable at 150rpm, barely able to read the disks..

HD support on the Amiga is rather useless for the most part.. Just use a catweasel board if you need to read HD floppies?

[aquanaut]

This is my first post here, so, hi everyone!

Originally Posted by DrF

The IBM part number reveals very little, all it brings up in Google is IBM 1.44Mb 3.5" floppy, I would assume its some rebranded drive and then IBM stuck a sticky on or something.

Drf: That's a YEDATA 702B - 6039 B and i am having the same problem as you. It boots and reads fine but it doesn't write correctly with xcopy. DS0 and RY are correctly selected at the pin header and RY and DC routed to pins 34 and 2 respectively.

I also modified a samsung SFD-321B/K-LB but the behaviour is the same. Boots, reads but it doesn't write.

I'm using an A500.

[rkauer]

This is what I'm was talking about in the last post:

For me it works perfectly, all you need to do is:

1- Set the unit as DS0, instead of DS1 (standard for IBM floppy drives);


2- Route the 34 pin trace to pin 2 and cut it from 34;

3- Join pins 30 & 34.

Works perfectly with any drive, if you locate the ds0/ds1 switch/shunt/selector/whatever. Even with Xcopy and Non-DOS games.

[rkauer]

Oh, BTW: this is not my original idea/hack.

Thanks to Hernan (aka Elpiloto), from Argentina to this easy and reliable hack!

[Jope]

I really like the simplicity of that one. :-)

Way to think outside the box on Elpiloto's part..

You don't even need to locate a DS0/1 switch, just twist wires 10-16 like on a PC floppy cable.. If you want to connect two drives to a big box Amiga, twist 4-6 as well.

[aquanaut]

Originally Posted by rkauer

1- Set the unit as DS0, instead of DS1 (standard for IBM floppy drives);


2- Route the 34 pin trace to pin 2 and cut it from 34;

3- Join pins 30 & 34.

Works perfectly with any drive, if you locate the ds0/ds1 switch/shunt/selector/whatever. Even with Xcopy and Non-DOS games.

I did the same mod on 4 drives (yedata, samsung, alps and nec) and they all behave the same way. They boot, read but xcopy reports error 8 (unable to verify) at DF1: when writing. Even if the drive is properly selected as DS0:.

Note: It does make a copy of a disk but, it reports 100 % errors in all sectors and it takes about five times more time to copy a disk.

I have no problems with time, the fact is that one cannot know if the copy has no errors.



Just to put aside a probable faulty cable, i inserted the original chinon and it performed correctly on all the tasks.


I remember reading an article in pdf, regarding the issue of amiga drives. It had a small schematic with a 74ls300 or 74ls03 that was used to plug between the amiga cable and the pc drive.

Does anybody have a link to the pdf?

[aquanaut]

Geez!

I finally discovered what was going on!

While i was testing the modded drives, i just copied 4 or 5 sectors (to check quickly if the drive would work with the amiga),so, i didn't have the need to killsys. None of the modded drives was reported by xcopy as writing correctly.

When i inserted the original chinon, i clicked on killsys because i wanted to make a full copy to rule out all the possibilities. Well, it read and wrote correctly. So, this made me conclude that the cable was fine and i was doing something wrong, but i did the mods as exactly as described by Rkauer, and with known moddable drives.

Well, Apparently i am using a xcopy version that has a bug. IF i have the memory expansion inserted and i DON'T killsys, it reads fine the source disk BUT xcopy reports error 8 at DF1 (i have only one drive, DF0) on the destination disk!

This never came to my mind because i always killsys to use all mem available.