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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Ral-Clan on January 26, 2013, 03:56:38 AM
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Hi,
Years ago I purchased (second hand) a Power XL internal High Density floppy drive for my A2000. It looks like this:
http://img.photobucket.com/albums/v299/asm016/Amiga/Tower/18102009095.jpg
It is essentially a PC High Density floppy, with a circuit board stuck onto the end that makes it operate with an Amiga.
Although the original owner told me it was fully functional, I never got it to work in my A2000.
So, years later (today) I have decided I will finally do a full and thorough test to see exactly what is the problem.
I connected it to my bare, stock A2000 motherboard (with WB3.1 ROMs, ECS).
First I tried it with the original Sony made HD floppy drive Power Computing supplied attached to the A2000's internal floppy header. It activates and shows the "insert floppy screen", but when I insert a regular Double Density Workbench floppy the disc drive whirrs for a bit and its light goes on, but then the same "insert floppy" screen shows up again. So it apparently can't read any discs. I've tried many known working Amiga discs.
I attached a few other PC HD floppy drives by Panasonic to the Power Computing board and they do the same thing.
Then I attached a Mitsumi made PC HD floppy drive to the Power Computing board. Now it will accept the Workbench disc (or any other double density Amiga formatted disc) and will boot up - no problem. I also tried a second Mitsumi floppy drive and it worked too.
Mounting PC0: also allows me to use it to read/write PC formatted 720K dics.
So apparently, this PowerXL board will allow Mitsumi PC drives to function as Amiga Double Density floppy drive no problem.
But - the Power XL was sold as a way to use PC HIGH DENSITY floppy drives with one's Amiga as an Amiga High Density drive. I have never got this to work.
The Mitsumi drives will not recognize a HD floppy disc when inserted. It will only allow me to format it as a 880K Amiga disc or a PC 720K disc.
So, very strange. The board seems to be function, but will NOT fully function as a High Density drive.
Any ideas why it is not working?
Oh - yes, I the Power Computing patch that comes with the drive is installed and running.
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Well...as a last resort I moved a jumper on the original Sony Floppy Drive that switched the floppy from "AT" to "AUTO" - whatever that meant.
Now it loads up and boots from Amiga Double Density disks just - just like the Mitsumi.
However, no luck with HD floppies.
It won't let me format HD floppies as HD floppes, only as 880K floppies.
When I install a HD PC formatted floppy into it I get the following warning message:
ERROR VALIDATING FILE ALLOCATION TABLE...PROCEED AT YOUR OWN RISK
....well...a little further than before I guess but no luck yet.
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Did you use Highdensitypatch? This piece of software was supplied with the power Computing HD Floppy drive.
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HighDensityPatch is required to be able to write to HD disks. What version do you have? I think 1.4 was the last one.
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Yes, I'm using HighDensityPatch 1.4. No luck with High Density disks though.
Is there any history with certain Amiga 2000 motherboard revisions not working with HD internal floppies?
I had an external HD floppy drive by another manufacturer which did work with this Amiga.
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You may find this helpful.
http://eabmobile.abime.net/showthread.php?p=212195
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and more info for cross dos if you intend to use for PC disks, but my advise get it working with Amiga first. then focus on PC0 after.
http://www.l8r.net/technical/t-crossdos.shtml
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Thanks Erol,
I've actually already seen that link on EAB and am currently using the 1.4 version patch.
Thanks for the info on CrossDos. I've been using it for many years with double density disks.
I should mention to everyone that I now have gotten ALL the PC High-Density floppy drives to be recognized by the PowerXL board as Amiga double density drives. Before some of the drives had not worked with this board (Panasonic, Toshiba). I connected them as DF1 and they work now, but again, only as DD drives.
So, still having the problem with it not recognizing any drives as HD.
I don't have another Amiga to test the drive on, but can it possibly be the rev4.4 motherboard?? Strange, as my DELL external HD drive works with this motherboard.
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Thanks Erol,
I've actually already seen that link on EAB and am currently using the 1.4 version patch.
Thanks for the info on CrossDos. I've been using it for many years with double density disks.
I should mention to everyone that I now have gotten ALL the PC High-Density floppy drives to be recognized by the PowerXL board as Amiga double density drives. Before some of the drives had not worked with this board (Panasonic, Toshiba). I connected them as DF1 and they work now, but again, only as DD drives.
So, still having the problem with it not recognizing any drives as HD.
I don't have another Amiga to test the drive on, but can it possibly be the rev4.4 motherboard?? Strange, as my DELL external HD drive works with this motherboard.
I'm not sure how the PowerXL HD floppy works, but to use a Commodore HD floppy drive in an A2000, you have to have the motherboard jumper for DF1 set to off, because the drive identification signal is provided by the drive. If you have it set to on, the motherboard provides this signal and the Amiga will always think that the disk in the drive is low density.
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I'm not sure how the PowerXL HD floppy works, but to use a Commodore HD floppy drive in an A2000, you have to have the motherboard jumper for DF1 set to off, because the drive identification signal is provided by the drive. If you have it set to on, the motherboard provides this signal and the Amiga will always think that the disk in the drive is low density.
Okay, new development.
I am back to testing the PowerXL board with the original Sony drive it came with. I have my Amiga DD drive set to DF0: and the PowerXL drive set to DF1:
As I said, when inserting a PC formatted HD disk I get the error message mentioned above.
When I try to format the HD disk, it now recognizes that there is a HD disk inside, as it the Format window says something like "Formatting PC1: to 1440 OKAY CANCEL?"
But when hitting okay, the computer Gurus.
It will not even allow me to try formatting the disk as a HD Amiga disk. Only gives me the 880K option.
Talk about crazy hardware behavior!
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The PowerXL drive will have to do the same as the Chinon FB357A in an A4000 - it needs to run at 150rpm. How it does this I'm not sure - you may well find that the drive isn't an entirely normal PC drive, and is dual-speed like the afore-mentioned Chinon. That said, the controller chips must do something funky, and the HighDensityPatch is obviously necessary for something....
Basically be aware that the apparently normal drive in the XL drive may not be as normal as it seems!
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No worries, may be a stupid question but is the patch at the bottom of your user-startup sequence?
Also you must close J301 on A2000 (DF1 as HD Floppy Drive) and check the the floppy drive cable is installed correctly, seems obvious but check all the pin are not bent and you have no tears or kinks in the cable.
try this format tool, see what happens
http://aminet.net/package/disk/misc/Formatter
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I used to have a couple of the Power XL drives, both external and internal. The external drives worked fine with my A1200 - but not my A2000. The internal I could get working IF it was DF0, and there were no second internal drive. I never did get that resolved. Sorry for such dark forecast.
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The PowerXL drive will have to do the same as the Chinon FB357A in an A4000 - it needs to run at 150rpm.
No it buffers the track and then shifts it back at half speed. Doing the opposite for writing needs the patch for some reason.
It probably wouldn't be too expensive to make something similar. I'm surprised jens hasn't done one.
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@psxphill
Thanks for that, I wasn't sure.
I should try my own PowerXL drive and see what happens when I try it with a different PC drive.
So does the interface convert from DISKCHG to RDY as well then?
Edit: don't forget to check if it needs a drive belt. Many Amiga drives are Citizen mechanisms like you find in the Sam Coupe, and if the belt's gone or bad it won't be turning the spindle properly.
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Edit: don't forget to check if it needs a drive belt. Many Amiga drives are Citizen mechanisms like you find in the Sam Coupe, and if the belt's gone or bad it won't be turning the spindle properly.
Sam Coupe doesn't have spare Citizen drive belts anymore.
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So does the interface convert from DISKCHG to RDY as well then?
I don't know. I only read about them, never had one.
http://ftp://ftp.cs.tu-berlin.de/pub/aminet/docs/rview/PowerMDisk.txt
"If you want faster access, there have been other attempts to
work round the problem with mixed success. The Power XL Drive uses a
buffer to handle the data sent to the Amiga. This, as the DiskSpeed
results below show, works reasonably well. The other solution is the
untested Catweasel board, which basically acts as a replacement floppy
controller."
I had one of the variable speed dell laptop drives that came out after commodore went under.
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Quazar usually have Sam Coupe belts, which can be used in Amiga Roctec drives too.
If your PC drive is configured for DISKCHG and not RDY then it won't work.....
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UPDATE
Well, today I pulled an old A500 Revision 5 out of the garage loft and tried this PowerXL High Density floppy drive in it ------ and wouldn't you know it? THE BLOODY THING WORKS! Recognized a high-density floppy disk right away! I didn't even need to use the PowerXL patch.
So it WAS the revision 4.4 A2000 motherboard - because heaven knows I tried every single jumper setting and cable permutation I could think of and nothing ever worked.
So ---- after ten years ----- mystery SOLVED.
As an aside, the old Chinon 880K floppy drive in this A500 was also very weird. It absolutely HATED any high density media formatted to Double Density (even when the extra hole was covered with tape). 9 out of 10 high density floppies formatted to Double Density (and known to work fine on other Amigas) would either not be recognized at all by that Chinon drive, or load partially then refuse to go any further. I don't know how it knew - there was no sensor pin for the high-density hole in the drive. It just must have not like the magnetic bias of the particles or something. Second weirdest thing I've ever seen pertaining to Amiga floppy disc drives!
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UPDATE
Well, today I pulled an old A500 Revision 5 out of the garage loft and tried this PowerXL High Density floppy drive in it ------ and wouldn't you know it? THE BLOODY THING WORKS! Recognized a high-density floppy disk right away! I didn't even need to use the PowerXL patch.
So it WAS the revision 4.4 A2000 motherboard - because heaven knows I tried every single jumper setting and cable permutation I could think of and nothing ever worked.
So ---- after ten years ----- mystery SOLVED.
As an aside, the old Chinon 880K floppy drive in this A500 was also very weird. It absolutely HATED any high density media formatted to Double Density (even when the extra hole was covered with tape). 9 out of 10 high density floppies formatted to Double Density (and known to work fine on other Amigas) would either not be recognized at all by that Chinon drive, or load partially then refuse to go any further. I don't know how it knew - there was no sensor pin for the high-density hole in the drive. It just must have not like the magnetic bias of the particles or something. Second weirdest thing I've ever seen pertaining to Amiga floppy disc drives!
I've read over the years that DD floppies are higher quality than HD floppies, but with the drives it's the other way round.
Hence, an HD drive will read and write HD and DD no problem, but a DD drive will read and write DD, but may struggle with HD.
From this I understood it was always better to buy DD floppies and they will last longer even in and HD drive.
Of course this coudl be total nonsense, but it is what I read and seems to make sense that as drive technology improved, the media didn't need to be made to such a high standard (expense).
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I've read over the years that DD floppies are higher quality than HD floppies, but with the drives it's the other way round.
Hence, an HD drive will read and write HD and DD no problem, but a DD drive will read and write DD, but may struggle with HD.
From this I understood it was always better to buy DD floppies and they will last longer even in and HD drive.
Of course this coudl be total nonsense, but it is what I read and seems to make sense that as drive technology improved, the media didn't need to be made to such a high standard (expense).
I think the info you were given might be incorrect. From what I understand, the difference between DD floppies and HD floppies is not that DD floppies are "higher quality", but that they have a different formula of magnetic particles coating the disk surface - i.e. particles with a different magnetic bias than HD floppies (i.e. so they take a different strength of magnetic field to charge).
HD floppies have a particles formulated so they can hold higher density data despite the fact that they are using much narrower tracks and sectors. I'm guessing this "HD formula" requires a higher magnetic charge to write to and the particles are more "tenacious" (i.e. holds onto its polarity well despite a smaller area being used).
So from what I understand, the HD floppy drives can sense which disk is inside it (DD or HD) via a sensor pin that detects the presence / absence of the extra hole in the floppy casing, and so it alters the magnetic bias of the head to appropriately read/write to the type of disk that has been inserted.
Now....SOME DD drives don't seem to care that there when an HD floppy has been inserted. Obviously, with no sensor pin for the "HD hole" they can't know what type you've inserted. I've found that MOST DD drives will still happily read and write to a HD disk (except the one from my A500 mentioned previously). The danger, is, of course that if they DO write to an HD floppy, the drive head is not calibrated to put out the proper strength magnetic field for the "High density" particles. So, while the particles on the disk surface MAY be altered by the drive head, and the floppy may even work for some time, the particles are more weakly charged than they should be, and the disk may fail in weeks or months.
Alternatively, if you use a double density disk in an HD drive, and somehow cut out the extra notch so that he HD drive thinks you have inserted a HD floppy, and then format that disk to HD format etc. then again the magnetic bias is not matched to the particles on the disk surface - and I am assuming that since the HD bias is probably stronger, the particles on the floppy would become over saturated, and you would get reliability problems as well, if it held data at all without corrupting adjacent tracks.
Now, if you use a DD disk in a HD floppy, and it has the appropriate notches to identify itself to the drive as a DD disk, then the drive will adjust the magnetic bias of its head to appropriately read and write to DD floppies properly (as if it was an old Double Density drive).
It's like the old case of cassette tapes: regular Ferric Oxide standard quality cassette tapes and CrO2 high quality tapes, and even higher quality METAL tapes. You had to flip a switch on your recorder marked "bias" to signal to the cassette recorder what magnetic strength to use when recording. Some more expensive cassette recorders could sense by the notches in the cassette's casing what kind of tape had been inserted. But again, if you used the wrong bias on the wrong type of tape, the quality of your recording would suffer. With an analogue signal, usually you could still hear something - although it might be more or less noisy / distorted.
Anyway, this is how I understand it. If anyone can correct me or set me straight, feel free.
Now, as for DD floppies being "Higher Quality" --- well, they may be less likely to fail. I could see that. But I think that would be the result of the data being less tightly packed on the disks. The tracks and sectors have more room to "play" (further apart) and slightly mis-alignments in a drive's head (or from drive to drive) are not going to cause errors as much as where the tolerances are higher (on an HD disk, for instance). I've always found my old 1541 drive on my VIC to be very reliable - and thought that this might be one reason for that - only 360K or something per side. So maybe the lower read error rate of lower density media gives the impression they are "higher quality" to some.