High Density External Drive

[Interceptor]

'ello guys,


does anyone know if i can replace a standard external amiga drive with the modern PC unit?

i know it physically fits into the same casing, but will it work as normal?

i dont need it to read HD disks, just behave like a normal amiga drive will do?

i've tried looking for hacks and stuff on aminet etc etc but nothing really seems to clear this up.

any definitive answers?

or is there any chance of blowing the controller if i try it out?

cheers!

[ElectroBlaster]

M8 visit Eyetech! they sell a small hardware adaptor called "EZ-DF0"

it will say "Sony to DF0" but dont let that fool you into only buying a sony drive as ANY pc generic drive works :)

and the best part :) its only a FIVER :))))

[oldpx]

But Interceptor wants to replace his external drive, will that work just the same way then?

[ElectroBlaster]

Yes but the downside is the eject button and you might have to alter the 1200's casing for the drive's plastic front...

unless you can find a drive thats the same make as the internal amiga drive and swap bits over like the eject button etc...

i know panasonic ju-257's are still the same so if you can source on of them and a dead amiga one your in luck :)

[oldpx]

Sorry but I'm still unsure if we understood each other right. As far as I understand that drive will be connected as DF1: not as a DF0: replacement. I hope Interceptor might clarify this.

[ElectroBlaster]

DOH! my fault... not reading this right....

i see interceptor wants to replace the floppy unit on an external drive with an off the shelf pc HD unit! what external drive is it?
i know early power computing one's wont work but the power XL High density does!

i have two no-name units that had oridnary pc hd drives in them and that worked perfect on a pc we nabbed them for some time ago! i still have the drive mechs but there aint any markins on the circuit boards.... i will find them and test with a sony and a teac we have lying around..

[oldpx]

DOH! my fault... not reading this right....

:) We all miss details sometimes. (I corrected a mistake of mine in the previous post :D)

[Overdoc]

Ok, I don't know about all external drives, but the ones I have all have Amiga drives in them. But anyway, these drives cannot be put in as internal ones without cutting the case of an A-500 or A-1200 because they have the eject button in a different position.
Don't know if these also work in a PC - never tried it. But if I put a standard PC drive in the external case, then it won't work ( or only for DOS based programs )

If you want to use a PC drive as Amiga DD, then you will have to build a smal circuit board, which you can find on Aminet. There are several hacks on Aminet, and there also is one that just tells you to modify the cable, which unfortunately will not work ( will work only for DOS based programs )

So I think it is easier to get the adapter from eyetech. Another possibility would be to rebuild the adaptor that came with Escom A-1200 computers, which also had a PC drive from factory.

Btw., if you have a Panasonic JU257.... then you can modify it to work with Amigas :) There is a small jumper on the underside of the circuitboard which you will have to cut and solder to a another pad.

[ElectroBlaster]

Overdoc

These 2 external drives used panasonic ju257's and they were proper pc drives, they were untouched!

when i find the cases i will try another make drive in it! if it works then i will try and identify who possibly built these externals etc...
the only other things i can tell you is the metal case is the usual biege but seems like it's a copy of an older design and the paintwork aint very well done and they have silver covers on the 23pin plugs.. not much i know :confused

it was like they were made only a few years ago, maybe 1996 onwards as they were in perfect condition when i got them so maybe some company took the trouble to find a way to get off the shelf stuff to work instead of sourcing proper amiga devices...

[Interceptor]

indeed, i'm trying to connect the drive as DF1: and have it work as a normal DD drive.

i have 2 drives here, both are panasonic JU-257

one is the A607P version

one is the A606PC version

the latter seems to have various sw1's etc that have references like RY/DC and another has PC/AT/P2/SE

maybe i can get some schematics for this thing.

thanks for the info thus far guys, top stuff :)

[Overdoc]

@ElectroBlaster:

The characteristical thing of Amiga drives is that they have the DC (diskchange signal) on pin 2 and the RD (ready signal) on pin 34, while PCs have them swapped or at least have DC on pin 34. ( I think the PC doesn't use the RD signal and therefore PC drives won't work with e.g. games that have their own loader )

So I think the reason why these drives worked unmodified with your PC is that you didn't change disks and therefore the drive didn't have to use the diskchange signal, which most probably is on pin 2 on your drives.
But it could also be possible that it is infact a PC drive and the small electronics inside the external drive does correct the drives PC pinout for Amiga use.
But I don't think this would work with all PC drives, since most newer ones don't even have a RD signal or have it with other timings than the Amiga needs. Try putting a standard PC drive in the external case and see if it works.
Would be interesting !
All external drives I had had Amiga drives in them, although they looked PC like.....

@Interceptor:
If your drive has an DC/RD jumper then that jumper should be set to RD. You can try if the drive works then and if it also can recognize disks when you change them ? Otherwise you will have to connect the DC signal to pin 2 manually.

On one JU257 drive ( don't know the exact number ) there should be 3 small pads on its lower side of the PCB.
For PC use, the one with DC written besides is soldered to the middle one. For Amiga use you have to cut this conection and solder the middle pad to the one called RD. Then you have to make a small wire and solder the DC pad to pin 2 of the connector and the drive sould work for Amiga :)

[ElectroBlaster]

Right then lads!

I have found both empty drive cases these ju257's were part of!
I have tested a Teac HD pc drive and it works perfectly! I didnt have to do any mods at all :) *it works 100% with copying, formatting and disk swaps :D

As to the make of these exeternal drives Im lost as their aint any name, numbers or stickers :(
*I have just removed the circuit board and found this name:
AMDIPAN V1.... never heard of em???

I will scan both floppy drives and the circuit board thats in these external cases and upload them to the zone for whoever wants to see them!

:)

[Overdoc]

Oh, yes, if you could upload that then this could be very helpful !
Another test you could do ( do be 100% sure ) is load a game that doesn't use normal dos routines for loading, but has it's own loader. Just take a game for testing that has at least 2 disks and makes use of external drives.
I once swapped a PC DD drive into my A-500 as external drive and it worked fine in normal dos, but didn't work with ndos games that have their own loader. This is because of the different ready signal, which Amigados doesn't make use of, but other loading routines do !

Btw., also newer A-1200 models which were made by Escom ( the ones which have Amiga 1200 written on them instead of Commodore 1200 ) do have PC drives in them which are connected via a small board on the back of the drive.
Some nice guy from the net who has such a A-1200 once drew a layout of this board for me ,but I haven't rebuild it yet to test it out.....

[jmmijo]

I have a number of spare external floppy drives that I've collected over the years. Some have Teac and others Panasonic or Sony drives in them One thing I've noticed about all these drives is that there is usually a small circuit board inside these cases that goes inline with the drive unit, connected by an angle connector or by ribbon cable. So it could be that these manufactures have resolved the problem with the disk change and any other missing signals via these boards as they usually have at least a small DIP chip(gates and/or inverters) and some support components on these boards.

Perhaps that small Sony-DF0 board does this same thing. It wouldn't surprise me ;)

[ElectroBlaster]

At least this way it wont be so hard to get another drive easily and fit it without building custom circuits and bodges!

i just wish I knew who made these externals I have here.....
then everyone could track one down!

[jmmijo]

You were going to scan them in and send the pics to the zone right?

Oh, did you actually look on the connector end of the drive? Sometimes the manufacturer hides a small sticker there!

[ElectroBlaster]

The pics are already in the zone m8 :)

[jmmijo]

Got em, thanks. I'll review them and see what there is to see ;)

EDIT: as for one drive that has always worked for me, but it's a DD model from Sony. So if you can find it then grab one or two.

The model is MPF110-05

The -05 I believe is the revision so most likely you may only be able to search on the first part of the model.

Now as for HD drives, so far none of the drives I've tested has worked as a sub in any of my external drive units :( Could be because of the HD part or some other missing or changed signals on the connector.

This could be why the Sony-DF0 board was made to allow you to use these HD drives.

[ElectroBlaster]

My sony DF0 adaptor wont allow me to format HD disk's and thats with any make drive which is a shame :(

I have 2 high density external drives! one is a laptop drive with a special lead and the other is a power computing model with the same sony drive you mentioned! i assume i could also swap that drive mech out but iv'e had bad luck with power-c stuff..
i have broken a few of their drives in the past! way too easy to kill em :( so i leaving it well alone and hoping it wont die on me!

[jmmijo]

Well keep in mind this model Sony drive is a DD drive, note the missing HD hole sensor on the bottom!

This would of course preclude you from formatting a HD diskette.

Not sure you could swap it out with a HD unit as I thought the external HD drive units for the Amiga had to use special driver software, but of course my memory is not what it used to be :sad

EDIT: I've reviewed the pics and must say that these are about as generic as it gets. I bet the name on the circuit board is the actual board manufacturer, most likely not the manufacturer of the drive.

Are there any labels or marking on the actual plastic/metal casing?

I remember the ones from I believe Oceanic Pacific, think they came in a neat plastic molded case with their logo on it and I believe they were the ones that offered a track display option model as well ;)

[ElectroBlaster]

your right m8! the power-c one does use a patch which is called in the startup-sequence to make it format and read HD floppys!

the other drive i have doesn't need any software or patches but the lead is a bit crap and flimsy, thats the only downside on that one!

[jmmijo]

I've not been able to find any info using the amdipan name on the circuit board. I've tried variations of the name and found that dipan comes up as an Indian name, found lots of links to these people's pages ;)

[Overdoc]

Originally posted by jmmijo
I have a number of spare external floppy drives that I've collected over the years. Some have Teac and others Panasonic or Sony drives in them One thing I've noticed about all these drives is that there is usually a small circuit board inside these cases that goes inline with the drive unit, connected by an angle connector or by ribbon cable. So it could be that these manufactures have resolved the problem with the disk change and any other missing signals via these boards as they usually have at least a small DIP chip(gates and/or inverters) and some support components on these boards.

Perhaps that small Sony-DF0 board does this same thing. It wouldn't surprise me ;)

Well, I once swapped such a drive from an external unit ( it was a Sony ) over to the internal connector of an A-500, and it worked perfect also as internal. So this is why I don't believe all external drives have PC drives in them, but I think these drives are modified for Amiga use, although they are PC drives as we can see from the eject button. But the small PCB which is in there is for other purpose, I think

ElectroBlaster's external units seem to be special ones which really have PC drives in them.
But it is easy to find out:
Just try if the external drive works as internal, and try if a normal PC drive will work if connected to the pcb in the external unit. That should bring light into this case :)

Btw, other PC HD drives that I know you can make work on the Amiga are:
Panasonic JU257..... ( have to be modified )
Chinon FZ-357 ( has to be jumpered correctly )
some Mitsubishi drive I cannot remember the number from

In theory all drives that have a DC/RD jumper on their back should work, but I'm not sure on this.

[Interceptor]

righty,

seems like this

JU257-A607**** - these are not changable AFAIK (any new info on this then please let me know)

JU257-A606PC - these are the later boards with no resistors, only pads which need tracks to be cut - unfortunatly i managed to f*ck the stepper motor cable on this one before i got that far :(

JU-A606P - this is the exact model that is described in the aminet docs, i performed the mod only to find the mechanics were buggered.....

...but i was lucky that a computer came in with another A606P...but alas the board is just a little different, and my best guess at the modification resulted in the drive thinking there is a disk in there all the time. double arse :(

next step, replace the good board onto the good mechanical one and hope it works..

i'm determined to win this one! thanks again for all the feedback

[Overdoc]

Hehe, making a good one out of some broken ones :)

But you could als check the disk insertion sensor at the one that always thinks there is a disk in the drive. It is a small pin on the left side, right behind the write protect pin.
Also, some drives have the track-0 sensor mounted to the PCB, which means you have to realign it after changing the electronics. Don't know about the Panasonic from memory, but I think some TEAC drives are made like this.
If you want to give realigning a try then search here in this board for the word "align" and you might find some help I once wrote here.
But let's hope your Panasonic has the sensor mounted on the chassis. That would save you a lot of trouble !

Good luck :)

[Interceptor]

bloody hell, what a saga....


well, i replaced the board, now the poxy thing cant see when there is a disk in the drive. i've mega-checked the mods on the board, i moved the mod wire directly to pin 2 to see if that helps, which doesnt.

is there any way i can test the logic on the board to see if it's the drive or me or just the weather?

if not, hammer is waiting........which is nice.....

cheers!