A1200 issues with HD LED and FDD spinning

[guybrush]

I have a 1200 in a case, so I have extensions LED for power and FDD; although the LED for the HDD stays always on. I am using a SD2IDE adapter as hard drive.

The LED on the SD2IDE device is red to show the device is on, and green when there is disk activity; it flash fine so I guess something is wrong with how the Amiga read those info from the device? I did not remember if I had the same issue while using a CF2IDE adapter; but it is not super useful to have the HDD LED always on, and being unable to see the disk activity. How can I fix this?

Also my FDD spin every time my Gotek is reading or writing data (they are connected in sequence; and I have a switch for the drive selector I made, modifying a floppy ribbon cable, so I can flip drives at will).

You can hear the floppy drive motor go on at full speed (the one that make the disk spin, not the head motor) every time I have the gotek selected and I am reading an ADF file; and this is concerning me because it could reduce the lifespan of the actual floppy drive of course. I could disconnect the power on the floppy, but then I would need to open up the case when I want to use the floppy instead of the gotek. Is there any off the shelf solution or pre-made cable that allow you to flip between a gotek and a floppy but that turn off the floppy too?

[LIV2]

You can find the fix for the ide led here: [ Show youtube player ]

As for the floppy, your drive switch needs to disconnect the MTRON signal from the floppy drive when it is switched over to the gotek

[guybrush]

Originally Posted by LIV2

You can find the fix for the ide led here: [ Show youtube player ]

As for the floppy, your drive switch needs to disconnect the MTRON signal from the floppy drive when it is switched over to the gotek

Thanks for the video, but that video show a different problem. My LED turn on; it is not turning off to show activity; but instead is showing the state of the SD2IDE adapter (which has a solid LED when you turn on the computer).


I can try to find the equivalent pin on the SD2IDE, because it is quite different from the CF2IDE adapter, and see if that makes a difference. For reference this is what my device looks like:


https://www.ebay.com/itm/35342983671...Cclp%3A2047675


Also which pin is the one you mention? I can't see anything with that name on the Amiga internal connector descriptors
http://www.primrosebank.net/computer...orage_fdis.htm

[LIV2]

Sorry, I linked the wrong video: [ Show youtube player ]

There are a couple of options listed by Jan, a resistor fix: https://forum.amiga.org/index.php?topic=72859.0
Or a mosfet fix: http://megaburken.net/~patrik/Amiga%...%20Fix/fix.txt
And lastly an adapter pcb: https://rastport.com/products/KA47/

The floppy signal is listed as MTR0 on that page. Note that the gotek doesn't use the motor signal so you don't need to switch this over to the gotek you only need to disconnect it from the floppy drive when switched over

[lesta_smsc]

Originally Posted by guybrush

Thanks for the video, but that video show a different problem. My LED turn on; it is not turning off to show activity; but instead is showing the state of the SD2IDE adapter (which has a solid LED when you turn on the computer).


I can try to find the equivalent pin on the SD2IDE, because it is quite different from the CF2IDE adapter, and see if that makes a difference. For reference this is what my device looks like:


https://www.ebay.com/itm/35342983671...Cclp%3A2047675


Also which pin is the one you mention? I can't see anything with that name on the Amiga internal connector descriptors
http://www.primrosebank.net/computer...orage_fdis.htm

I have an SD2IDE adaptor and used 2N7000 N-Channel MOSFET to fix HDD light issue. It's on the forum here with the photo of how it was connected:

http://eab.abime.net/showpost.php?p=...&postcount=157

[Krashan]

Originally Posted by guybrush

My LED turn on; it is not turning off to show activity; but instead is showing the state of the SD2IDE adapter

Not really. The problem is a bit different and is caused by the fact that SD2IDE uses 3.3 V logic levels. Pin 39 of the IDE bus signals drive activity and controls Amiga HDD LED. It is active low signal, so the converter sets pin to 0V when the card is active and to 3.3 V when it is inactive. Note that regular HDD will set the pin to somewhere between 4.5 to 5.0 V when inactive.

Amiga 1200 uses a simple circuit with a PNP bipolar transistor to drive the HDD LED. At 0.0 V on pin 39 transistor is turned on, LED lits. At voltages above about 4.3 V the transistor turns off. Now you see the problem. While for the SD2IDE 3.3 V means "inactive", transistor will stay turned on. So LED will lit permanently, ignoring any activity changes.

Fixes for the problem have been listed by LIV2, above.

[guybrush]

Originally Posted by LIV2

Sorry, I linked the wrong video: [ Show youtube player ]

There are a couple of options listed by Jan, a resistor fix: https://forum.amiga.org/index.php?topic=72859.0
Or a mosfet fix: http://megaburken.net/~patrik/Amiga%...%20Fix/fix.txt
And lastly an adapter pcb: https://rastport.com/products/KA47/

The floppy signal is listed as MTR0 on that page. Note that the gotek doesn't use the motor signal so you don't need to switch this over to the gotek you only need to disconnect it from the floppy drive when switched over

No worries, thanks for the video! Now I can see the issue and understand what is going on. The adapter seems the best solution but it cost 35 dollars, and I am not really planning to get it at that price to be honest, so I will probably go for the resistor fix or the mosfet, considering the cost involved.



Thanks for the info on the floppy signal; so I can just disconnect that pin when switching over to the gotek; that should be simple enough! BTW I already have a switch that route the signal to the CS pin to either the gotek or the floppy; can I add the MTR0 signal on the same switch on the same pin, or would that short the circuit? If not I need to buy a switch with 2 poles, so I can connect the 2 signals, even if all I want to do with the second signal is to disconnect it when I use the gotek. Thanks!

[guybrush]

Originally Posted by lesta_smsc

I have an SD2IDE adaptor and used 2N7000 N-Channel MOSFET to fix HDD light issue. It's on the forum here with the photo of how it was connected:

http://eab.abime.net/showpost.php?p=...&postcount=157

Thanks, that thread was very informative! The picture is quite small, how did you connect the mosfet on the SD2IDE adapter? Also would that work better than adding the resistor on the ribbon cable? Looks much easier to do than solder on those small adapters

[guybrush]

Originally Posted by Krashan

Not really. The problem is a bit different and is caused by the fact that SD2IDE uses 3.3 V logic levels. Pin 39 of the IDE bus signals drive activity and controls Amiga HDD LED. It is active low signal, so the converter sets pin to 0V when the card is active and to 3.3 V when it is inactive. Note that regular HDD will set the pin to somewhere between 4.5 to 5.0 V when inactive.

Amiga 1200 uses a simple circuit with a PNP bipolar transistor to drive the HDD LED. At 0.0 V on pin 39 transistor is turned on, LED lits. At voltages above about 4.3 V the transistor turns off. Now you see the problem. While for the SD2IDE 3.3 V means "inactive", transistor will stay turned on. So LED will lit permanently, ignoring any activity changes.

Fixes for the problem have been listed by LIV2, above.

Thanks for the info; After looking at LIV2 video I got the issue finally

[lesta_smsc]

Originally Posted by guybrush

Thanks, that thread was very informative! The picture is quite small, how did you connect the mosfet on the SD2IDE adapter? Also would that work better than adding the resistor on the ribbon cable? Looks much easier to do than solder on those small adapters

Please check on this link for both instructions and a clearer picture of what mods are required:

http://megaburken.net/~patrik/Amiga%...D%20LED%20Fix/

[guybrush]

Much appreciated Do you think that the fix with MOSFET is better than adding the resistor on the ribbon cable? Just want to be sure I get the best solution in the end, and don't cause problems in the long run

[jlin_au]

The adapter board: https://rastport.com/products/KA47/ is probably your best option in that case as it uses a digital 74HCT14 IC to convert the 3.3v logic levels of the SD2IDE to the 5v logic levels required for the A1200 or A600.
A Rasport KA60 dual port adapter (https://rastport.com/products/KA60/ , https://www.ebay.co.uk/itm/164085687630, or https://retroready.one/collections/a...600-amiga-1200https://www.ebay.com/itm/12480200792...IAAOSwkl5XfkCt) is a good alternative as well.

An alternative in the USA is the AmSider from http://amigaonthelake.com/amsider-sd-adapter/

[guybrush]

Good news, a 40 cents resistor on the IDE wire 39 fixed the issue.
No need for soldering, nor for extra adapters!

Last thing I need to fix now is how to turn off the floppy motor when I am using the Gotek, but from my understanding, I need a 2 pole switch, so I can use one switch to disable the motor pin on the floppy cable and switch the drive selector pin between the 2 devices.

[lesta_smsc]

Originally Posted by guybrush

Good news, a 40 cents resistor on the IDE wire 39 fixed the issue.
No need for soldering, nor for extra adapters!
.

Lol well done! What size resistor did you use?

How did you add this without soldering?

[guybrush]

Originally Posted by lesta_smsc

Lol well done! What size resistor did you use?

How did you add this without soldering?

Tried with a 15K and it is working OK. The brightness is a bit high from what I can tell, and the LED seems to never completely turn off so I guess I can push up to 18-20K and that should do. I have no other resistors at the moment so I will need to go to the local part store and get some more.


The whole process took 2 minutes; and while I understand it is not a proper solution since I am fundamentally wasting a resistor to lower the voltage on pin 39, it seems to do the trick. On the positive side, I can replace the ribbon cable and everything is fixed; so nothing permanent neither on the SD2IDE nor on the motherboard

[lesta_smsc]

But HOW did you insert it without soldering... where did you 'slot' resistor?

[Krashan]

Originally Posted by guybrush

I am fundamentally wasting a resistor to lower the voltage on pin 39

This is fundamentally not true. The transistor on Amiga mobo is a PNP one, it turns on when its base is on low woltage, turns off with 5 V on the base. Your resistor limits the base current, so it makes it "harder" for the transistor to turn on, and voltage on the base is in fact higher with the resistor, not lower.

The effect is transistor is not fully turned on when SD is active (so LED brightness is less than before), but it is almost turned off when SD is inactive. A step in the right direction.

[guybrush]

Originally Posted by lesta_smsc

But HOW did you insert it without soldering... where did you 'slot' resistor?

Oh, you mean how did I install it?
I cut the wires apart, so I can isolate the wire on pin 39, then I cut it and wrapped the exposed wire to each leg of the resistor, then I used shrinkwrap to seal the connection. There is no stress on that cable since it is never touched so I didn't bother to solder it.

[guybrush]

Originally Posted by Krashan

This is fundamentally not true. The transistor on Amiga mobo is a PNP one, it turns on when its base is on low woltage, turns off with 5 V on the base. Your resistor limits the base current, so it makes it "harder" for the transistor to turn on, and voltage on the base is in fact higher with the resistor, not lower.

The effect is transistor is not fully turned on when SD is active (so LED brightness is less than before), but it is almost turned off when SD is inactive. A step in the right direction.

I get that the transistor is what is doing the work; but the resistor is what allow the transistor to not hit the threshold to go high; so it won't be on all the time



I didn't touch much hardware electronics since college but to what I remember, if I add a resistor on a wire, voltage stay the same 5V, but current goes down.
Ohm,'s law is pretty straightforward; if you know voltage (5V) and resistivity (300 ohm), you can get the current (0.016A). If I change voltage and keep the same 300 ohm resistance, then current will change (in this case, using 3V and 300 ohm the voltage will be 0.1A)


But in the end what matter is that it works

[lesta_smsc]

Originally Posted by guybrush

Oh, you mean how did I install it?
I cut the wires apart, so I can isolate the wire on pin 39, then I cut it and wrapped the exposed wire to each leg of the resistor, then I used shrinkwrap to seal the connection. There is no stress on that cable since it is never touched so I didn't bother to solder it.

Ah... I was beginning to wonder it was connected by some other means lol.