Weird A4000 floppy problems

mrluff · 11 February 2009, 16:07

I got an A4000 some time ago cheaply with the CyberstormPPC/CybervisionPPC. The Cyberstorm and Cybervision has seemed to work well, although both CPU's and the GPU get very hot (problems under solving).
I have a selection of ide-drives, scsi-drives and cf-cards, and have experimented with them with and without success.
I've generally had a few weird problems, some naturally solved and some not solved at all. The problem that bugs me right now is with simply booting floppies.

I strip the machine down to only Cyberstorm, no ram (but 2MB chip), no ide or scsi drives, no expansion cards and connect only DF0:. I put in an original 3.1 Install disk and start the machine. It checks the drive for half a second and give me the insert disk picture. I put in the original 3.1 WB disk and same thing happens.
I try my own backup copies, and my friend's original disks and same thing.
Then i put in an old 1.3 wb disk with some programs, and it boots right up.
I try the 3.9 emergency disk and it also boots up (as far as it makes it without scsi-disk and 3.9 cd-rom).
What the h*ll is going on?

alexh · 11 February 2009, 18:51

Bit rot? Do the disks work in another Amiga?

Floppy disk drive motor / mechanism fault, perhaps it is restricting what areas of the disk you can read which results in one disk working and another disk not due to the location of the data?

Swap out the disk drive if you can.

StingRay · 11 February 2009, 19:33

My best bet would be rotten disks too.

Quote:

perhaps it is restricting what areas of the disk you can read which results in one disk working and another disk not due to the location of the data?

The bootblock is always at the same location of the disk so I don't think that this is the problem.

mrluff · 11 February 2009, 20:01

thanks for replying; to rule out floppydrive failure (but maybe not floppy controller failure?) i have tried my external df2: drive and it gives the same results with the same disks. its so strange, that all 3.1 disks don't work, and old ones, and the 3.9 emergency disk, boot right up.
the 4000 has 3.1 roms, i have been suspicious of those afther the problem occured, is there a reason to? i'm pretty sure all disks booted up at some point earlier and so the problem is new. i've tried cleaning the drive with cleaning disk/fluid too.

mrluff · 11 February 2009, 20:25

disks work in my friend's A600, no problem, excuse me for not saying such things in the beginning.
another detail; when a bootable working floppy is inserted, say 3.1 Install, or any other bootable floppy that should have been booting, it will load a few seconds like normal, then a couple of seconds of very short loading sounds on interval; then stopping totally. often after a while i get "software failure". but the disks work in other machines.

alexh · 11 February 2009, 21:32

Possibly RAM problem or CPU issue.

mrluff · 12 February 2009, 14:53

I've done some more research;

-changed chip ram to several others, machine starting but no change to the problem
-changed to another 68060, machine starting but no change to problem

I'm starting to think that the 3.1 ROM's are somehow not working right?
I have no spare ROM's for the A4000, but I will get two pairs in a giant lot I will be buying soon. Also in the lot is the original A4000 cpu-card wich I don't have from before, so I will test with that too, to exclude the Cyberstorm as the problem.
I can also see almost the same pattern when connecting harddisks as when inserting floppies. Partitions will show but those that are bootable will not boot, 3.1, 3.9 etc.

rkauer · 13 February 2009, 03:18

Those kinds of problems can be related to ripple (noise) on the +5V line, too.

Worth checking it with an oscilloscope. If ripple appears, swap the electrolytical caps.

Also check the voltage levels: under 4.85 or over 5.2V and you will have issues.

mrluff · 13 February 2009, 04:46

thanks for replying, will test voltage etc..

mrluff · 14 February 2009, 15:12

@rkauer

i switched the powersupply to another ATX one, and I have the same problems (working 3.1 install/wb floppies not booting), can i then say I have excluded the voltage/power-stuff from the list of potential problems? Or do I have to measure voltages on the board itself? I have a multimeter, where should I in that case measure on the board?

Next step for me is to try other 3.1 roms. I think the problem of not getting the 3.1 floppies to boot, seem like the same problem as when you have too old ROM's compared to what OS version you are trying to boot. Like if you try to boot 3.1 floppies with 1.3 ROM's.

11 February 2009, 16:07	#1
mrluff Registered User Join Date: Mar 2008 Location: Norway Posts: 46	Weird A4000 floppy problems I got an A4000 some time ago cheaply with the CyberstormPPC/CybervisionPPC. The Cyberstorm and Cybervision has seemed to work well, although both CPU's and the GPU get very hot (problems under solving). I have a selection of ide-drives, scsi-drives and cf-cards, and have experimented with them with and without success. I've generally had a few weird problems, some naturally solved and some not solved at all. The problem that bugs me right now is with simply booting floppies. I strip the machine down to only Cyberstorm, no ram (but 2MB chip), no ide or scsi drives, no expansion cards and connect only DF0:. I put in an original 3.1 Install disk and start the machine. It checks the drive for half a second and give me the insert disk picture. I put in the original 3.1 WB disk and same thing happens. I try my own backup copies, and my friend's original disks and same thing. Then i put in an old 1.3 wb disk with some programs, and it boots right up. I try the 3.9 emergency disk and it also boots up (as far as it makes it without scsi-disk and 3.9 cd-rom). What the h*ll is going on?

11 February 2009, 20:25	#5
mrluff Registered User Join Date: Mar 2008 Location: Norway Posts: 46	disks work in my friend's A600, no problem, excuse me for not saying such things in the beginning. another detail; when a bootable working floppy is inserted, say 3.1 Install, or any other bootable floppy that should have been booting, it will load a few seconds like normal, then a couple of seconds of very short loading sounds on interval; then stopping totally. often after a while i get "software failure". but the disks work in other machines. Last edited by mrluff; 11 February 2009 at 20:31.

14 February 2009, 15:12	#10
mrluff Registered User Join Date: Mar 2008 Location: Norway Posts: 46	@rkauer i switched the powersupply to another ATX one, and I have the same problems (working 3.1 install/wb floppies not booting), can i then say I have excluded the voltage/power-stuff from the list of potential problems? Or do I have to measure voltages on the board itself? I have a multimeter, where should I in that case measure on the board? Next step for me is to try other 3.1 roms. I think the problem of not getting the 3.1 floppies to boot, seem like the same problem as when you have too old ROM's compared to what OS version you are trying to boot. Like if you try to boot 3.1 floppies with 1.3 ROM's. Last edited by mrluff; 14 February 2009 at 16:25.

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11 February 2009, 18:51	#2
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,432	Bit rot? Do the disks work in another Amiga? Floppy disk drive motor / mechanism fault, perhaps it is restricting what areas of the disk you can read which results in one disk working and another disk not due to the location of the data? Swap out the disk drive if you can.

11 February 2009, 20:01	#4
mrluff Registered User Join Date: Mar 2008 Location: Norway Posts: 46	thanks for replying; to rule out floppydrive failure (but maybe not floppy controller failure?) i have tried my external df2: drive and it gives the same results with the same disks. its so strange, that all 3.1 disks don't work, and old ones, and the 3.9 emergency disk, boot right up. the 4000 has 3.1 roms, i have been suspicious of those afther the problem occured, is there a reason to? i'm pretty sure all disks booted up at some point earlier and so the problem is new. i've tried cleaning the drive with cleaning disk/fluid too.

11 February 2009, 21:32	#6
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,432	Possibly RAM problem or CPU issue.

12 February 2009, 14:53	#7
mrluff Registered User Join Date: Mar 2008 Location: Norway Posts: 46	I've done some more research; -changed chip ram to several others, machine starting but no change to the problem -changed to another 68060, machine starting but no change to problem I'm starting to think that the 3.1 ROM's are somehow not working right? I have no spare ROM's for the A4000, but I will get two pairs in a giant lot I will be buying soon. Also in the lot is the original A4000 cpu-card wich I don't have from before, so I will test with that too, to exclude the Cyberstorm as the problem. I can also see almost the same pattern when connecting harddisks as when inserting floppies. Partitions will show but those that are bootable will not boot, 3.1, 3.9 etc.

13 February 2009, 03:18	#8
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	Those kinds of problems can be related to ripple (noise) on the +5V line, too. Worth checking it with an oscilloscope. If ripple appears, swap the electrolytical caps. Also check the voltage levels: under 4.85 or over 5.2V and you will have issues.

13 February 2009, 04:46	#9
mrluff Registered User Join Date: Mar 2008 Location: Norway Posts: 46	thanks for replying, will test voltage etc..

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