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Any hope for a faulty Floppy emu v1.7 revc ?

V

Vipersan

Experienced Member
Joined
Apr 12, 2020
Messages
66
I have been given a faulty emu ..
No idea of it's history..nor what happened to it..
did it fall or was it pushed ?
Symptoms are..
Nothing on the oled screen ...but running without the oled plugged in...finger temp check on the chips..indicate the cpld running cold....but the cpu/atmega gets hot quite quickly.
power led lights up but the status led never does.
I suspect the atmega and / or possibly the regulator.
The oled pcb checks out ok ..as this was easily fitted in my emu....so at least I have a spare display...but it is such a waste not to have it running.
any advice with regards to this would be appreciated.

Shipping it back to the USA from the UK may prove to be more than it is worth.
 
Just a guess but someone probably used it to run a smart port emulation (like total replay) without doing the mod necessary outlined on the bigmessowires website. Result being a burned out unit.

Floppy Emu SoftSP Warning | Big Mess o' Wires

www.bigmessowires.com www.bigmessowires.com

I have done this mod to both my floppy emus (version B and C). The discussion explains the prolonged exposure to the voltage "accumulates" and causes cpld damage. I can honestly say i ran both my emus (but mostly my model B ) unmodded for a while before stumbling across this article and doing the mod. They both work fine but who knows if I caused some damage
 
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If you read the Comments, Steve from BMOW gives the part number to a replacement cpld. So you or someone with SMD experience can replace the chip. Doing a firmware update will reprogram it
 
Thanx for the heads up on that pin 12 mod...I'll be modding a cable for my emu..going forward.
As to the faulty emu... I suspect it isn't the cpld that is faulty...
I suspect the atmega micro..(it does get hot whereas the cpld does not)
If that was also available I have a friend with younger eyes ..that might try to replace this smd.
I'm making assumptions but the atmega most likely is not just a micro but but also contains a preprogrammed bootloader ?
rgds
 
Vipersan said:
Thanx for the heads up on that pin 12 mod...I'll be modding a cable for my emu..going forward.
As to the faulty emu... I suspect it isn't the cpld that is faulty...
I suspect the atmega micro..(it does get hot whereas the cpld does not)
If that was also available I have a friend with younger eyes ..that might try to replace this smd.
I'm making assumptions but the atmega most likely is not just a micro but but also contains a preprogrammed bootloader ?
rgds
Click to expand...
Well Id be curious how things go so please post updates when they happen and good luck.

As far as the Atmega I think you are right. Just send a message to Steve to have him confirm.
 
Some news on this emu..
I had contacted Steve the other day..and received this reply this morning.
>>>
From your description it sounds like the mcu might be damaged, but it’s impossible to say for sure. Unfortunately BMOW no longer offers repair service for out of warranty hardware since it usually didn’t make financial sense versus the replacement cost. If you have experience with SMD rework and microcontroller programming, then it might be possible to fix on your own, and I can send you a programming file for the mcu if you wish. But beyond that I’m afraid we’re not able to offer technical assistance or support for people who are performing mods or repairs on their own.

Best wishes,
Steve

>>>
BIG up Steve..
It may well be that this floppy emu will live again.
 
Nothing to report as yet..
The replacement atmel arrived x2 ...always good to have a spare.
I have passed on the emu ...the atmel...and the software provided by Steve...to my friend who has been tasked with flashing and fitting.
He will be doing this at hs place of work..in his own time.
Obviously I dont want to pressure him.
I hope to report success at some point...fingers crossed.
so..when I know...this thread will get updated.
rgds
 
Just sent this email to Steve...hopefully he will reply.
>>>>
Some progress has been made Steve.

It took me a while to fit the micro...and some pin headers to allow in circuit programming.

Finally got the micro responding.

Currently using an external regulated 3.3v

I have an unhappy smily face the status LED slow flashing.

...and looks like I have fuse errors 62 99 FF.

see attached photo.

Now what ?

The emu is not connected to an apple computer at this point.

can you please advise ?

I guess the Xilinx could also be faulty...but happy to see some signs of life.

regards

>>>>>>
anyone have any suggestions whilst I wait ?
 

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TBH Verault..
I haven't tried flashing the firmware as yet...
I was hoping Steve could at least confirm this would be correct so far.

I am a newb when it comes to flashing/programming so I'm being slow and careful.
what version firmware do you recommend Verault..?

I have also attached the bootloader kindly provided by Steve...
Just in case anyone else ever needs it.
 

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Didnt steve say in his message, swap the IC and just reflash the firmware per usual. Its easy. just go to https://www.bigmessowires.com/floppy-emu/ scroll all the way down to firmware and get the most recent for the model C and follow the instructions. Its super easy. Its not going to harm anything
 
VERAULT said:
Didnt steve say in his message, swap the IC and just reflash the firmware per usual. Its easy. just go to https://www.bigmessowires.com/floppy-emu/ scroll all the way down to firmware and get the most recent for the model C and follow the instructions. Its super easy. Its not going to harm anything
Click to expand...
I followed the process ..with v 240208A firmware in the root of an SD card...(an original older B/C firmware)
then with the emu powered up with the fuse errors displayed..holding down prev and select ...pressed RESET for a second.
No response from the EMU at all.
My guess is that the bin file (merged) although written to the atmega1284P completed...did not automatically set the micros fuses correctly.
So I guess I cannot proceed without addressing the bad fuses issue ?
Still holding out hope that Steve will give me a hint...though he may not want to.
I simply dont know what to do next.

pressing reset and then releasing RESET causes the oled display to go off and the staus led to stop blinking ..a second or so after this the oled display returns and the status led resumes slow blinking.
pressing any of the other buttons even for a moment changes nothing on the display but the status led never resumes blinking.
only removing the 3.3v supply then restoring it will make the emu resume the slow blink. (original state).
so..reset appears to be working ....getting a response/reset of the micro....but the other buttons ...err ...nothing except stopping the slow blink of the status led.
 
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Vipersan said:
I followed the process ..with v 240208A firmware in the root of an SD card...(an original older B/C firmware)
then with the emu powered up with the fuse errors displayed..holding down prev and select ...pressed RESET for a second.
No response from the EMU at all.
My guess is that the bin file (merged) although written to the atmega1284P completed...did not automatically set the micros fuses correctly.
So I guess I cannot proceed without addressing the bad fuses issue ?
Still holding out hope that Steve will give me a hint...though he may not want to.
I simply dont know what to do next.
Click to expand...
Keep us posted on what Steve says. Its possible its a bad chip I guess.
 
VERAULT said:
Keep us posted on what Steve says. Its possible its a bad chip I guess.
Click to expand...
I just hope Steve replies..
He might feel helping me isn't worth his time.
He hinted as much in the previous email reply to me.
 
Looks like I was right about programming the micro fuses.
Woke up to another reply from Steve >>>

Hi, you will need to program the configuration fuses on the microcontroller. The correct values are low: BF, high: DA, extended: FC.

Steve
<<<<
also made him aware I am documenting my process on VCF.

I hope he is OK with this...
cant see why he wouldn't be.

I doubt any progress will be made before next weekend as I can only get my friend to help on sundays.
 
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....and we have a winner....
Fuses are now set correctly.
a very early firmware version flashed to the Xylinx...which I'll update later.
I do hope this thread will be helpful to other members.
rgds
VS
 

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