Modifying PC floppy drives for Amiga use

[Vasquez]

Originally Posted by supaduper

HOW to

Hello supaduper,


I did everything as in the picture you sent me, but it is not clear to me for the double arrow in the lower right corner that shows JC30.
Should I close JC30 or it have to be open?
And on JC31 is a 000 resistor, hould I close JC31 or it have to be open?

[Sim085]

I did not know where to put this, I think this is the best place.

I have modified ju257a606p as documented here. The conversion works fine.

However want to add that if you have a broken original A500+ floppy drive ju253033p then you can replace the bottom floppy disk holder of the ju257a606p with that of the of the ju253033p and therefore you will be able to use the eject button of the ju253033p on the ju257a606p without any modification. Do not know if this works with other drives. Only tried this on ju257a606p.

[Isoroku]

I have a NEC floppy that was on the amiga when I bought it used a while ago.
It is modded pc floppy for amiga.
The problem is that I can not play multidisk game because every time I go to change disk it reboots amiga.
Floppy's board photo:

[katarakt]

Isoroku, the problem is that your mod is totally wrong !!!

At first, this NEC doesn't have real ready signal! ...but if you want to get it going with most games you have to do the mod right, i've posted already the correct mod here.

[Isoroku]

It works fine .
Thnx!

[avinitlarge]

It’s strange that this topic has been brought back to life. Today is the first time in a few years I’ve been playing with floppy drives and modding a few. I’ve got 3 Sony MP-F17W’s that are giving me grief.
Drive 1 seems to work fine but it just won’t write a disk, I’ve taken the heads from another drive and it’s still the same.
Drive 2 is strange, it will load up xcopy but if I try to read/write/verify etc it will say there is no disk in the drive, if I eject the disk and put it back in, it will read it ok.
Drive 3 is scrap and just for spares

[MoonDragn]

Wow it never even crossed my mind to use a pc drive for the Amiga... I do have a few old ones lying around. Maybe someday when I retired I will have time to play with them. Never enough time to do everything you want to do.

[katarakt]

Originally Posted by avinitlarge

I’ve got 3 Sony MP-F17W’s that are giving me grief.

I have a good working Sony MP-F17W-2Z pc drive, but i don't know where the ready signal is but it probably have it somewhere on the sony controller ic or on the board maybe.

Sadly, i can't find the pinout from this sony chip and measuring is too hard, because the chip is on the underside and many pins are not connected.

[littlebalup]

I had a Panasonic JU-256A316P PC floppy drive that I wanted to modify for an A500.





I couldn't find any information on modifying this specific model so I did a bit of research and experimentation on my own. It's pretty simple and elegant. And it works. Here are the changes to do:

- move R42 resistor to R41 (it switch DS1 to DS0)
- move R45 resistor to R46 (it switch PIN 34 from Disk Change to Ready signal)
- remove R47 resistor (that resistor originaly connects PIN 2 to the main chip for Density Select)
- bridge the R47/R48 common (center) pad to the R45 free pad (it connects Disk Change to PIN 2)

Pre-mod:


Post-mod:


enjoy

[amigasith]

Nice one, @littlebalup

[Jope]

Thanks, littlebalup. Can I add that to my drive modification page (credited of course)?

[littlebalup]

Originally Posted by Jope

Thanks, littlebalup. Can I add that to my drive modification page (credited of course)?

Yes of course

[katarakt]

Great work @littlebalup

[Turrican_3]

Searched for this model, but found no hits so I'll just post it here, perhaps it might prove useful for other fellow users.

I've just found a Teac FD-235HF 5165 unit and I can happily confirm it is possible to modify it for Amiga compatibility.

Apparently, the modification required is the same used in the FD-235HF 5291-U model, that you can see here:

https://honi.hucki.net/teac.html

(I'm just reposting the picture here for convenience, I'm not the author nor I do take credit)

[luigi75]

Originally Posted by katarakt

For Teac FD-235HF 3217-U try set the jumper to:

1A with 1B
3A with 3B
4C with 3C
4E with 3E
4G with 3G
Also set jumper to "Frame Ground" on the upper left

Let me know if this works

I used this configuration but RDY signal was missing (I use Amiga Test Kit 1.8), so I moved the jumper from 3A-3B to 4A-4B.
Both RDY and DC work perfectly now.
Hope this could help, even though the post is quite old.

[katarakt]

Great you found another setting that works luigi75

[RomanWorkshop]

I have 3 versions of modified Samsung SFD-321B drives: /KPGW REV. T1, /LNEC1 REV. T3 and /LE REV. T3. They are working great, read/write works on Workbench, FileMaster, X-Copy, Sanity Arte demo is running. But on D-Copy 2.0/3.1 whenever I want check/copy any good disk, I only get red errors "4" ("False track number") on all blocks. I changed "SPD"/"ATT." parameters and copy modes with no effect. Do you have the same problem with your modified Samsung SFD-321B drives and D-Copy?

[katarakt]

Samsung SFD-321 are only working great, if you're not going to format a disk with verify in the workbench itself! Maybe this D-Copy software uses some dos routines or something similar wich the workbench is using.

It has to do something with a standby/poweroff function within the drive's controller. It has real ready signal, real DC signal but it is is not 100% amiga compatible due to the motor power off/standby thing. Try format with kick 1.3 and workbench 1.2 or 1.3. I'm not sure if 3.1 has this problem, i've done these tests long ago.

Tested drives with this error (all modified to real Amiga drives with real ready signal):

Samsung SFD-321B /EZ Rev. S2
Samsung SFD-321B /MACT Rev. M2
Samsung SFD-321B /E Rev. K
Citizen Z1DE-62B

[jasonsbeer]

I am wondering if anyone knows where the ready signal can be found on this board from an SMD-340 drive. This was asked back in #67, but the proposed solution does not match this board revision.

[kinmami]

Originally Posted by jasonsbeer

I am wondering if anyone knows where the ready signal can be found on this board from an SMD-340 drive. This was asked back in #67, but the proposed solution does not match this board revision.

Do JP03 or 04, 05 switch (using the 0ohm resistor) between pin 2 and pin 34?

I have found a Japanese page https://98epjunk.shakunage.net/fdd/smd340_fd1231t.html
which tells about the pin assignment https://98epjunk.shakunage.net/fdd/f.../smd340_34.gif