Sony 920 MPF z/121 fix for Amiga

[kipper2k]

Originally Posted by Akira

OK kipper, I plugged it to the Amiga and it does the classic "3 clicks then DF0:???" stuff.
I seethe drive's light blinking all teh time! Never seen such a thing.

It looks like the mod didn't take. Check your soldering and do a meter check on the traces to make sure they are good, if all looks good, hang it from a barn door and see if you can kill it at 50 yards

[Amiga1992]

Well now I don't know what the hell is up.
I took the disk drives that I had marked as working, put them on this AMiga and they all came up as DF0:???? !!! This Amiga has been recently recapped. WTF?

Anyway, tested them all on the Amstrad: they work FINE.
So the mod should be alright. but it's still not working.
I tried plugging in the data cable the other way around and nothing either.

How can I check te hcontinuity of the traces I cut?

[kipper2k]

Originally Posted by Akira

Well now I don't know what the hell is up.
I took the disk drives that I had marked as working, put them on this AMiga and they all came up as DF0:???? !!! This Amiga has been recently recapped. WTF?

Anyway, tested them all on the Amstrad: they work FINE.
So the mod should be alright. but it's still not working.
I tried plugging in the data cable the other way around and nothing either.

How can I check te hcontinuity of the traces I cut?

You'll need an ohm/multimeter to check them properly

[Amiga1992]

Originally Posted by kipper2k

You'll need an ohm/multimeter to check them properly

I have a multimeter and I have checked the connections which all seem fine, but I mean, the traces I cut, which pins on the disk port header do they correspond to?

I wanna know if I cut them properly and/or if I cut extra ones by accident.

Also: how do you switch this unit to DS0 or DS1??

The CPC Wiki says this drive is compatible and explains:
"Working: Panasonic JU-256, HD drive, needs jumper at 33-34 to force "Ready""

Didn't I just do that?
Perhaps I have to undo some of the other modifications?

[kipper2k]

Originally Posted by Akira

I have a multimeter and I have checked the connections which all seem fine, but I mean, the traces I cut, which pins on the disk port header do they correspond to?

I wanna know if I cut them properly and/or if I cut extra ones by accident.

Also: how do you switch this unit to DS0 or DS1??

The CPC Wiki says this drive is compatible and explains:
"Working: Panasonic JU-256, HD drive, needs jumper at 33-34 to force "Ready""

Didn't I just do that?
Perhaps I have to undo some of the other modifications?

As far as i can tell you have the same drive as me so i don't see why yours doesnt workIn the case of this drive, pin 10 and 12 (i think controls whether it is DS0 or DS1, this has already beeb set so no more changes are needed.

[Amiga1992]

Well some changes have been suggested at CPC forums, but now I tried to remove the bottom left cable and I lifted the fucking pad. This is ruined, as I don't know how the hell to fix it :@ How to trace it back?

I'm quite pissed off at myself right now.

[roy bates]

all is not lost mate.

just trace the connection backwards on the board it has to connect to something.

if you cant see it i'll do it for you.

going by a picture already posted,it connects to the 2nd pin down on the right of the main chip(counting from the top down) on the drive board mate.
just use a meter and buzz it out from the trace scrape a bit off to make contact if you have to.

but you will have to use really thin wire to connect it up(i would use mod wire(kynar))

[Amiga1992]

I really can't, but it seems it connects to a pin on the main CPU or whatever the black thingy on the middle of the pic posted is.
Seems exactly what you said: second pin from above on the right set of pins of the processor.

I'll see how this pans out. Anybody knows what connection that is? It might work without it.

[roy bates]

hi mate.

are you going to use it with an amiga or cpc?

[Amiga1992]

Not with an AMiga, nope.

[voyager_1701e]

Thanks for posting this all those years ago Brian!

I haven't read the whole thread, but I applied your mod successfully to a variant of the same drive. Mine is MPF920 z/161. One of the chips near to a wire jumper is oriented differently on mine, but a quick check with a meter found the correct placing!

Working A-OK

[kipper2k]

Originally Posted by voyager_1701e

Thanks for posting this all those years ago Brian!

I haven't read the whole thread, but I applied your mod successfully to a variant of the same drive. Mine is MPF920 z/161. One of the chips near to a wire jumper is oriented differently on mine, but a quick check with a meter found the correct placing!

Working A-OK

Holy Crap,

when you said " all those years ago" i had to check... 2009!! wow where did all that time go. I kept all the old floppy drives from old computers and still have lots... just in case

The Z/161 is in the thread too (post #26

any one have the schematic of circuit to make an external drive from a pc modified drive? thanks a lot!

[icbrkr]

Bit of a necro-bump.

I'm in the process of modifying one of these for my Amiga 4000T. I've tried a couple of different drives (all MPF920s). First a B/53 I think, and then a Z/121. After I do the mod, the drive is recognized. I can read disks without a problem. However, when I try to format a disk, it works for about 5-10%, and then pops up a requestor saying the disk had been changed (which obviously it hasn't). If I add a PC0 driver for the drive, it gets even worse - it's like both drivers are competing to read the drive and neither one of them know the other is working with it. If I put the original MPF520 back in the 4000T, everything works fine. I'm guessing something wonky is going on with the disk change or drive ready lines... ideas?

[icbrkr]

Never mind.. got it! I think the issue lies at pad SH1. Though I only soldered it to the lower half, I think it still somehow made contact to the upper half. I scratched a trace in between to make sure and resoldered to the lower part and it worked.

[icbrkr]

Okay... I thought it was working, I formatted a single disk, and now I can't format another one. I just tried converting yet another drive with the same results. I switched out the floppy drive cable for grins.. is there something different that needs to be done with a A4000T?

[icbrkr]

Solved! If anyone has this problem on a 4000T:

Do not perform the SW3 bridge. Leave it alone.
No need to run a wire from the IC.
No need to run any wires.
Move your jumper over for DF0 as in the original mod.
Cut trace 34 as in the original.
Everything works.

[dirkies]

Originally Posted by kipper2k

The model i used is the Sony MPF 920 z/121 which is still on sale in stores (and also the z/131 which i have not
seen).

I have two Z/131 drives here ready to mod, but PCB wise it seems some mix between an E131 and a Z121

Just from the picture someone could suggest where to solder towards IC2? The other mods (SW3, CN6, trace and pin 34, JC30, SH1) seems pretty similar, only the wire from pin 34 to the IC2 chip on the right is a question mark.

? (2nd pin from the bottom left, as the same BA6986FS chip was used in Z/161 and there Kipper linked it to pin34 on the connector) ?

[dirkies]

actually I will just do the same mod like the Z/161 as they look damn similar PCB-wise!

[dirkies]

ok, tried same mod on a Z/131 as kipper did on a Z/161, verified the cut trace and shorted JC30 instead of JC31, but no luck, in an A500 the drive led will stay on permanently asa you switch the Amiga on. No disk is detected, no click either.

Also tried to wire instead from pin 1 (CN6) to pin 2 (CN1) as with the Z/161, from pin 1 (CN6) to SH1 as he did on a Z/121 but same thing, drive led stays on all the time.

Any suggestions?
EDIT: strange, I googled around and it seems the Z series do not have a RDY signal anymore, hence the question how this works with other Z series. Some confuse the RD (read data) signal with the RY (ready) signal, which means using RD it will work in standalone, but will cause all other external drives to fail. Others say RY should be connected to GND, works but with some random niggles.
So maybe this won't work at all...