Modifying PC floppy drives for Amiga use

[Jope]

Yesterday night I noticed I had a Panasonic JU-257A606P sitting on my shelf..

I remembered that there was an article about that on Aminet regarding how to use it with the Amiga. So, let's download that and see.

It seems the article deals with a very old revision of the A606P, one that I've never seen in the wild.

Naturally the component positions are totally different in these that I've seen.

Oh well, the document told me enough. Get _RDY to pin 34 and _DC to pin 2, make the drive answer to DS0 instead of DS1.

So, judging by the grainy shot, I did the same as the author. I found the place where DC/RY switch is supposed to be, moved the SMD jumper from the DC position to RY and soldered a small wire from the DC pad to pin 2 on the data connector. Then I found the DS 0/1 switch position and moved the jumper block from DS1 to DS0. Slap the bugger back together and plug it into the A1700 that is conveniently without a top cover.

My trembling hands insert Sanity's Arte, a demo that is known to require the ready signal.

It works! Yay.

In case you didn't understand my written instructions, here's an illustration on how the SMD jumpers and wire are supposed to go:



So how to tell which one to get?



Notice the flexi cable that goes to the stepper motor. It has to go to the right for the above illustration to apply. This is if you feel that you cannot work it out on your own for a different PCB.

So what do I do today? Go down to the recycling center (it's open every day of the week :-D) and buy 10 A606Ps, taking care to get the same PCB revision as the one I had success with. I also purchased two that had different PCBs, one with the flexi cable going left and one that has a connector for the stepper motor.

The one with the flexi going left worked. Naturally the switch positions are different, but you can hopefully work it out on your own.

The one with the connector for the stepper cable didn't work, even though I tried to measure all the "switches" and verified that they are in the same position. Not a big deal, I can handle the financial loss. Perhaps it was broken to begin with or perhaps it just isn't Amiga friendly. :-)

I think that the best success will be on drives that have only two positions for the DC/RY switch. The one that failed had four positions there.



Eight drives, ready to be plugged into an Amiga. Anyone want to buy some? I'm probably going to ebay a few, but I'm also open for offers directly. These are great for aftermarket towers. (DS1 versions available per request)

I got rather quick at this.. 5mins per drive after a bit of practice. :-D

If you're wondering where three of them went, one is in my broken drives pile and two are in the A2000T.

These also work nicely in a dual drive configuration for a big box Amiga. If you want it to be DF1, don't swap the DS jumper. Have a cable with only wires 4-6 twisted. DF0 is DS0 and DF1 is DS1. Remember to close the "DF1 present" jumper on your motherboard.

Oh, please recommend other software that needs the ready signal! I'd like to test them more thoroughly. I have verified that Arte will not boot past the boot block without a ready signal.

[Zetr0]

@jope

A Great DIY post!!!! dankie!!!!

[narmi]

Has anybody else tried this mod? I have a spare JU-257A606P, so I tried it, but the drive will not read any disks. My A500 seems to recognize the drive, it does click, and does try to read a disk when I put one in, but it wont boot. The original drive does boot from the same disks I'm testing with.

Unfortunately I didn't test the drive in my PC first, so I don't know if it was working or not (though I'm pretty sure it was a working pull). Any ideas?

[a_petri]

Originally Posted by narmi

Has anybody else tried this mod? I have a spare JU-257A606P, so I tried it, but the drive will not read any disks. My A500 seems to recognize the drive, it does click, and does try to read a disk when I put one in, but it wont boot. The original drive does boot from the same disks I'm testing with.

Unfortunately I didn't test the drive in my PC first, so I don't know if it was working or not (though I'm pretty sure it was a working pull). Any ideas?

Are the floppy disks you trying DD (720K) or HD (1.4M) ones?

I had a similar problem with a modded Panasonic JU-257 and my 880K-formatted HD diskettes. I solved it by gluing a piece of plastic above the DD/HD sensing microswitch.

[Jope]

Yeah, put some sticky tape around the HD detect hole if you are using HD disks.

A quick solution that one might come to is to just simply bridge the HD detect switch permanently, but this kills diskchange.

[narmi]

All of the disks I tried are DD, so there is no HD detect hole in them. I made the same modification to a Samsung SFD-321B drive, as it also can be configured the same way, but it doesn't work either. When I put a disk in the Amiga tries to read it (click, click, click), but cannot. I think there might be a timing issue. Both of the drives I have are vairly new, perhaps they are built to a slightly different spec than older drives.

[Jope]

Ah, you didn't mention that you used a completely different mechanism.

Unfortunately I've never seen that one, but I have had similar experiences with other drives than the Panasonic this thread talks about.. I didn't really bother wasting my time with them that much, as the JU257A606P was a very common PC drive indeed.

If you have the time and energy to invest, then you might want to try scoping around with a known good drive and this one that doesn't work. I wouldn't, but I already said that. :-)

[narmi]

I've now tried a third drive, another Samsung SFD-321B. it also does not work. I'm sure this was working as I pulled it from a PC that was working last month. Now I have three drives modified (1 Panasonic, 2 Samsung) that don't work in my Amiga . Later on I'll undo the modifications so I can test them in a PC.

I'll have to track down some more Panasonic drives because I have 4 Amigas and only two working drives, both are original and old.

EDIT: All four of the floppy disks I was testing with are bad, including my original WB1.3 disk. It appears that my modified Panasonic drive did the damage. Both Samsung drives work wonderfully! I used them to copy a working Zany Golf disk, and boot from it (original and copy). But when I tried to boot the copy from the Panasonic drive, it did not work, and that disk is now unreadable.

I'll take pictures of the modded Samsung drive and post them soon. They were easier to mod than the Panasonic drive (larger solder pads).

[narmi]

As promised, more eye candy! The label below is from the first drive I modified. The second one has the same model number, but is a REV.T1 part. The PCB inside both drives is virtually identical.



The modifications are the same as for the Panasonic drive. Change the unit number from 1 to 0 via the DS1/DS0 jumpers, change pin 34 to RDY from DC by moving a zero-ohm resistor, and connect DC to pin 2.



The DS1/DS0 jumper is just a solder blob, I used a solder wick to remove the original blob, then I added another blob on the correct jumper. Pin 2 is connected to a jumper that is not used, so I used one of its pads to connect the DC signal rather than soldering to the connector. It's neater this way. Obviously I noticed the pad after I cut the wire to size .

I found the manual for this drive on the Amiga floppy project blog. If the manual can be trusted, all revisions of this drive should be moddable, good news since this can still be purchased new. It can even be found with a black faceplate, if you have a black case.

[Jope]

Hey that's cool. Very easy mod too, no need to unsolder the stepper motor cable like in the Panasonic. :-)

[narmi]

Jope, can I get a copy of that demo from you (the one that requires the RDY signal)? I bought and modded two more drives today ($2 each, why not?) and I'd like to test them a bit more thoroughly.

EDIT: Never mind, I found it on Aminet.

[laser]

there is no need to modify any pc floppy disk drive to make it works on the amiga

a simple modification of the floopy'data cable is the easiest solution:

it works fine I tested

http://aminet.net/docs/hard/PcF2AmF.lha

[Jope]

Some work with the 2-34 swap, but not all. The prefect (and neat) solution is to do real mods to the drive. :-)

[narmi]

I'm sure lots of things will work with the cable trick, but it's too easy for me. I like to open things up and tinker . In fact, if the mods were more difficult, I could probably make some money selling modified drives. AmigaKit wants $30 for a new drive, though they include a cable.

[laser]

Originally Posted by Jope

Some work with the 2-34 swap, but not all. The prefect (and neat) solution is to do real mods to the drive. :-)

I think the best solution is using a real amiga drive..cause lots of games not works using that PC drives modifications...idem problem with escom A1200'drives....

there's a hardware hack on aminet for the escom' A1200 drives...maybe that hack is needed also for the 34-2 swap to make the PC drive compatible with all games....I will check that one day when I have time

bye

[Chain]

We have same thread on czech amiga portal.
If anybody needs translation of some hack just ask.
They are all tested and works.

http://amiga.probers.info/forum/forumdisplay.php?f=129

[Jope]

Originally Posted by laser

I think the best solution is using a real amiga drive..cause lots of games not works using that PC drives modifications...idem problem with escom A1200'drives....

there's a hardware hack on aminet for the escom' A1200 drives...maybe that hack is needed also for the 34-2 swap to make the PC drive compatible with all games....I will check that one day when I have time

bye

Hi, Laser!

You are wrong. The modifications illustrated here are 1:1 functional Amiga drive replacements, full compatibility. Not comparable to the Escom A1200 drives, which were missing the READY signal. The mods we have shown here have that READY signal and have been tested with software that refuses to boot on an unmodified Escom A1200..

I'd appreciate it if you read what is written in the threads you reply to.

[Jope]

Here's my approach on the YD-702D-6037D A .. I know Chain's forum has a different approach, but try both and see what works for you.

Remove all jumpers except set the ry/dc jumper to ry and ds jumper to ds0



Remove shortcut block P12 from the pcb and solder a wire from the jumper block's DC pin to the pin 2 side of the P12 solder pads

[laser]

Originally Posted by Jope

Hi, Laser!

You are wrong. The modifications illustrated here are 1:1 functional Amiga drive replacements, full compatibility. Not comparable to the Escom A1200 drives, which were missing the READY signal. The mods we have shown here have that READY signal and have been tested with software that refuses to boot on an unmodified Escom A1200..

I'd appreciate it if you read what is written in the threads you reply to.

ah sorry...Im vague sometimes I have no cure
OK
if you are looking for software that requires ready signal:
I remember that the game lemmings 1 (cracked version with trainer) not worked on my modified drive,also not worked the game Troddlers (2 disk version /cracked/no trainer),ehhh..Sirius 7,(not remember very well... but you can try)

btw, How a data cable can be modified to make a full compatible amiga drive with ready signal?

[narmi]

Originally Posted by laser

btw, How a data cable can be modified to make a full compatible amiga drive with ready signal?

It cannot be done, since the ready signal is not present on the 34-pin connector of a PC drive. Some drives (those posted in this thread) have a ready signal available on their PCB which can be routed to the correct pin on the 34-pin connector.

[laser]

Originally Posted by narmi

It cannot be done, since the ready signal is not present on the 34-pin connector of a PC drive. Some drives (those posted in this thread) have a ready signal available on their PCB which can be routed to the correct pin on the 34-pin connector.

I understand now...so to make any pc drive works on the amiga this steps should be made:

1-set the drive to unit 0 using a jumper or link

2-route diskchange to pin 2

3-search ready signal on the drive and route to pin 34

is that correct?

[a_petri]

Originally Posted by Chain

We have same thread on czech amiga portal.
If anybody needs translation of some hack just ask.
They are all tested and works.

http://amiga.probers.info/forum/forumdisplay.php?f=129

Did I understand correctly that you have discovered another PC 1.44M floppy drive (the one shown in the "Alps Electric, alebo mrcha HDcka" thread) which can be modified as a *HD* Amiga floppy???

[Jope]

Originally Posted by laser

1-set the drive to unit 0 using a jumper or link
2-route diskchange to pin 2
3-search ready signal on the drive and route to pin 34

is that correct?

That's correct.

[laser]

thanks Jope

I have another question :

on the pc the "density select" is on pin 2..but if you route diskchange to pin 2...that function will be destroyed so no High density disk can be recognized on workbench (I think)

I know that the commodore A4000T comes with a high density drive.....so which pin is "density select" on the A4000T motherboard?

anyone have pinout of the A4000T internal floppy connector?..I can't find that info on the web

[gizmomelb]

has anyone ever managed to convert a PC HD floppy so it works with the Amiga?

Wouldn't an extra 'slowdown' circuit need to be added to the PC drive?

[Jope]

Originally Posted by laser

I know that the commodore A4000T comes with a high density drive.....so which pin is "density select" on the A4000T motherboard?

This is detected by trackdisk.device using the ready bit stream.

http://aminet.net/package/docs/hard/PCFloppy2Amiga has info on the ready pulses and other Amiga disk related issues.

anyone have pinout of the A4000T internal floppy connector?..I can't find that info on the web

http://www.wonkity.com/~wblock/a4000hard/inflpins.html

Originally Posted by gizmomelb

has anyone ever managed to convert a PC HD floppy so it works with the Amiga?

Wouldn't an extra 'slowdown' circuit need to be added to the PC drive?

I haven't heard of anyone doing it successfully. Reports have been that the drive doesn't spin reliably at 150rpm..

[gizmomelb]

thanks Jope! I'll get on with some reading.

Ok, Amiga semi-newb here at your service. I had an A2000 back in the day, but had a fire at the house and it got auctioned off for peanuts. Now years later, I decided I'de like to collect all the old games and stuff I had.. so I picked up an A3000 on Ebay for a bit over $200 US.

Problem... I can't seem to get anything running properly. Hero's of the Lance just gives me a read disk error screen. Some others kind of work, then die.

Champions of Krynn would load up using the floppy drive to boot up, but during the demo would freeze while loading a certain part.

Hillsfar makes it look like its going to load, but then just goes to a blank screen.

Starflight again, almost works, but when I go to start a new game I get disk write errors.

Ok, so I figured, maybe I have a floppy drive issue... all these A500 A1000 A2000 games should work on the 3000 right? (I couldn't get a straight answer on that one from anyone I asked).

So I bought an FZ-357 on ebay after seeing some spreadsheet somewhere that said it would work on an Amiga with no modifications.

Get the drive, install it, it doesn't work.. maybe I flipped the cable... still doesn't work. Ok , so now I find another site that says you have to take the drive apart solder the J2 jumper and set external jumpers... ok... so I manage to get all that done with some help. (Far from "no modifications").

I have high hopes... put in Champions of Krynn.. it looks like its going to work. Select to start the demo, it asks for disk 3, I insert disk 3 and nothing...nada..nil... Retry...retry...retry... nope... Its not even trying to read the disk.

Alright, well let me try the Heroes of the Lance. Nope, still get the red guru like disk error when trying to load that one. (Do I remember something about those silver box games all being PAL by accident? I dont rememeber, back in the day, I needed the guy from Electronic Boutique to make me some special PAL loader disk though to play that one, I thought maybe I accidentily bought a PAL version back then.. but maybe not?)

Any ideas what my problem is here?

Could it be 2 bad floppy drives?

A500, A1000, A2000 games not compatible with A3000?
Something bad in the machine itself somewhere?
I did try cleaning the original drive with a drive head cleaner disk and giving it a good squirt of compressed air. It didn't help.
If you think its a floppy drive issue, can I get one of these that your talking about in this thread?

Thank you for reading, I appreciate any assistance.

Originally Posted by narmi

As promised, more eye candy! The label below is from the first drive I modified. The second one has the same model number, but is a REV.T1 part. The PCB inside both drives is virtually identical.

Nice! I have the same drive in my PC. Can i use it my A500 if I do those modifications? Can i read/write HD-drives when i replace the drive?
EDIT: I discovered that the drive is to low. I can make some spacers and make the drive higher. The eject button is to centered but with some modifications to the plastic shell of the A500 solves that problem.

[narmi]

I use mine in my A500 to avoid wear and tear on the original drive. Try it and let us know!

Originally Posted by narmi

I use mine in my A500 to avoid wear and tear on the original drive. Try it and let us know!

Can you format HD discs with it or is it a limitation of the fdd controller?

[Jope]

You can format HD disks as DD.. Use a piece of tape over the HD cover hole. Naturally you don't get HD capacity or much reliability, but it is possible to use HD disks this way.

The floppy controller indeed can't keep up with the PC drive's HD datarate and also the PC drive does not supply the right identification pulse for the OS to know that the floppy you inserted is HD.. Thus the drives will work as DD only in Amiga use.

[Jope]

Originally Posted by rcosner

Ok, so I figured, maybe I have a floppy drive issue... all these A500 A1000 A2000 games should work on the 3000 right? (I couldn't get a straight answer on that one from anyone I asked).

No-one can remember the compatibility of all games.. :-)

Check http://hol.abime.net/ .. Even that doesn't have up to date info on everything.

I suggest you try and find a plain A500 to test the games on if you suspect bad disks.

So I bought an FZ-357 on ebay after seeing some spreadsheet somewhere that said it would work on an Amiga with no modifications.

This would be the FZ-357A .. The FZ-357 (without the trailing A) is the PC version which will need modifications..

Get the drive, install it, it doesn't work.. maybe I flipped the cable... still doesn't work. Ok , so now I find another site that says you have to take the drive apart solder the J2 jumper and set external jumpers... ok... so I manage to get all that done with some help. (Far from "no modifications").

..as you soon found out.

Any ideas what my problem is here?

Could it be 2 bad floppy drives?

It could..

A500, A1000, A2000 games not compatible with A3000?

Quite probable. The A3000 has a faster CPU with caches that will break many games.. Also kickstart 2.04 is a problem for some older titles.

Something bad in the machine itself somewhere?

Based on your explanation, it's most likely just the fact your games aren't A3000 compatible..

If you think its a floppy drive issue, can I get one of these that your talking about in this thread?

Sure.. Contact me if interested. However I'd try to get the games working on a plain 68000 machine first to see whether the media is broken.

Try and get confirmation on the drives working by using a regular DOS disk first, such as Workbench.

Can you boot up Workbench from floppy? Can you successfully copy your Workbench disk to an empty floppy with the drives you currently have?

Then once you know that the drive reads / writes properly, you might want to try relokick and/or degrader to turn off advanced features of the A3000 to help the games run. I think you should start testing with some other drive than the FZ-357 you mentioned, just in case the modifications didn't work.

[DrF]

I would love a HD drive just for err having it, I guess, I am hoping to order the CatWeasel this week, has anyone got any experiance with this device and various drives?

[Jope]

The Catweasel is pretty compatible, only a couple of models that don't work with it. Naturally you can not boot off HD disks even if you use a Kylwalda.

The Catweasel requires PC floppy drives, you mustn't modify them for Catweasel use.

Originally Posted by Jope

This is detected by trackdisk.device using the ready bit stream.

I haven't heard of anyone doing it successfully. Reports have been that the drive doesn't spin reliably at 150rpm..

Some guys on a1k did it.
http://www.a1k.org/forum/index.php?m...d=2&thread=572

I am one of the beta-testers and i made a testrun-movie.
http://www.a1k.org/download/area51/HDFloppyFix.mpg

Its a TEAC FD-235HF drive.
1760kb / 1440kb ofs/ffs/fat - read/write
880kb / 720 kb ofs/ffs/fat - read/write

First we had some problems with timings from the diskready-signal (hd-mode) in combination with an a1000.

[Jope]

Great news. I have a new project for you, please try and modify the JU-257A606P, as TEAC drives are very far in between around here. ;-)

When I have the energy, I'll read through that thread and try to understand what everyone's saying.

For some news (final revision) visit this page:
http://www.a1k.org/forum/index.php?m...ost_nr=680#680

Originally Posted by Ratte

For some news (final revision) visit this page:
http://www.a1k.org/forum/index.php?m...ost_nr=680#680

That looks like a thing worth building :-)

[Jope]

Can you give us a quick rundown? Does it require modifications to the drive in order to work, or is it some kind of track cache that reads the track and then feeds it half speed to the Amiga?