Chinon FZ-357A - stung again..

[ptp170]

Some of you may remember my attempts at getting a FB-357A running correctly about 6 months back... Well, to cut a long story short I never managed to find the issue.


Fast forward to now and thought I'd bite the bullet and just get a new Chinon HD drive and cut my losses on the old unit. Purchased a tidy looking FZ-357A from Deutschland and surprise surprise the ruddy thing doesn't work properly.

Now, I've checked the HD switch and that works correctly but whatever I do the drive speed never drops to 150rpm and sticks at 300rpm.

Anyone any ideas about this before I set light to everything in a fit of frustration...


TIA

Chris

 

[Deleted member 14264]

You don't mention what type of Amiga you're trying to get this drive to work on or the OS you're using.

I have an Amiga 3000 running OS 3.9 with an FB-357A and it works just fine. I can tell you however that back in the early 90s, when I bought my first brand new 3000, it was running OS 2.04 and the machine came with that type of drive and it worked with HD floppies.

The cable between the Amiga and the drive might be the culprit too.

 

[hooverphonique]

how are you testing? I have an FB357A, and running it outside the amiga, it spins at 300 rpm regardless of disk type, so it seems that it only drops to 150 rpm in case the amiga has actually read out the id bit stream (this is my theory, anyway). That also allows it to always run at DD speed in case the OS doesn't support HD (i.e. it doesn't read the id bit stream).

 

[ptp170]

It's been tried on two A1200's with 3.0 and 3.1 ROMs.

I'm using a program called 'Drivespeed' and 'DriveID' to verify with average RPM and ID stream...

It could be that the FZ operates differently than the FB but I would have expected the same drop in RPM either way..

Chris

 

[Deleted member 14264]

IIRC, the A1200 does not support HD floppy drives.

Let's just say I am really not 100% sure about this one.

 

[Arnie]

IIRC, the A1200 does not support HD floppy drives.

Let's just say I am really not 100% sure about this one.

I can confirm that the A1200 does support HD drives, I use one myself.

 

[hooverphonique]

It's been tried on two A1200's with 3.0 and 3.1 ROMs.

I'm using a program called 'Drivespeed' and 'DriveID' to verify with average RPM and ID stream...

It could be that the FZ operates differently than the FB but I would have expected the same drop in RPM either way..

Chris

does the id bit stream indicate that it's detected a hd disk?

 

[ptp170]

The ID stream indicates that the drive thinks it is a DD disk when a HD one is inserted... this is backed up by the rpm not dropping...


I'm assuming the jumpers are correct for the Amiga?

 

[Nobby_UK]

IIRC, the A1200 does not support HD floppy drives.

Let's just say I am really not 100% sure about this one.

I can confirm that the A1200 does support HD drives, I use one myself.

Ditto:
Mine was a 'Power Computing XL' Floppy with driver disk.

 

[ptp170]

Well this gets weirder... I've traced the HD switch right back to the logic /interface board and the trace stops at an unpopulated jumper J20! It goes no further nor does it split off anywhere else?!

 

[Deleted member 14264]

@ptp170
AFAIK, removing this jumper is the kind of mod you'd want to do if the drive was used on an Amiga which does not work with HD floppies or a 1581 ( C64/C128 ) disk drive.

 

[ptp170]

The attachment shows what's going on...

 

[Arnie]

Are you absolutely sure that this is a HD drive?
Can you post pics of the front with the bezel off?

 

[ptp170]

Are you absolutely sure that this is a HD drive?
Can you post pics of the front with the bezel off?

It does have the HD switch if that's what you're after??

 

[hooverphonique]

well, without those two populated, it definitely won't work.. it's weird that R16 (pull-down) is missing, because that leaves the HD input signal to the chipset flapping in the breeze.. Actually, it's also weird that the pulldown is on that side of the jumper, because then it can't act as a pull-down when the jumper is disconnected - very strange!

try hardwiring the input on the chip to +5V and see if it goes permanently HD..

 

[ptp170]

Right... I connected up the HD switch so that it can communicate with the main interface IC. This unfortunately didn't result in any of the charateristic Drive ID signal being generted on the RDY line upon disk insertion.

I can only come to the conclusion that this is a PC based drive inserted inside a 357A amiga shell to attempt to sell it for a high price.

I have requested my money to be refunded.

As a note of caution the eBayer still has a FB357A for sale in Germany so Amibayers beware!

 

[kneehighspy]

will a fz357 work as a high density drive in a a3000d? mine originally came with a fz357 but was willy nilly reading and writing 800k discs. tried hd disks but it always tried to format them as standard density.

just replaced it with a 354 and works fine, no read or write errors.

my 3000 has 3.1 roms, thats why i thought it would read hd disks. i guess i was wrong, any ideas?

 

[ptp170]

You would have been in the same situation as me above. If its just FZ357 and not a FZ357A then it won't be able to tell the Amiga about HD disks as the circuitry doesn't exist...