02 August 2019, 05:32 | #1 |
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A1200 Remove internal floppy; external as DF0:?
I’m thinking of a hardware project that would require the space currently in use by the internal floppy drive. If I remove the internal floppy will it be possible to make an external floppy work as DF0: for the times a floppy is the only way?
Ideally I would like to buy an external floppy drive in housing, then put it away until required and have the system boot from it like the internal floppy. But if connecting to the internal header is the only way this could work I might need to make a cable and housing to connect the original drive via a cable and an external housing to the internal header? |
02 August 2019, 10:30 | #2 |
ex. demoscener "Bigmama"
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What you need is basically a boot selector which swaps df0/df1. Installing such a thing in an A1200 can of course be a bit tricky due to the CIA chips being SMDs.
You can leave some connections out since you only need to wire the external port to be df0. |
02 August 2019, 10:35 | #3 |
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Run a ribbon from the internal connector out through the spare trap door at the back right of the machine (beside the mouse connector) and done.
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02 August 2019, 16:06 | #4 |
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Without modding the board, the internal header is the only place you can connect a drive as DF0:. It's not a complicated mod, but involves a little soldering and removing a resistor.
Incidentally, the A4000 has a jumper on the motherboard for this very function, mapping DF0: to the external port. |
03 August 2019, 01:48 | #5 |
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Well, I think I can do a neat job of making the internal floppy connector accessible. Thanks all...
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03 August 2019, 09:27 | #6 |
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31 March 2020, 12:19 | #7 |
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I replaced my internal FDD with a Gotek last year but now I would like the option of still being able to use floppy disks from time to time so I was wondering if it is possible to use my old internal FDD as an external DF1 drive. Is their a gadget out there that would enable me to do that please? I'm not necessarily bothered about putting it in a caddy if all that is needed is a suitable cable.
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31 March 2020, 14:01 | #8 |
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31 March 2020, 15:12 | #9 |
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Nice one, Vypr! That looks like exactly the thing I am after. Thank you very much.
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01 April 2020, 08:38 | #10 |
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01 April 2020, 13:54 | #11 |
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I appreciate that heads-up. My old internal FDD is a Panasonic one but I can’t see the voltage marked on the circuit board. Are these likely to be 5v do you know?
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01 April 2020, 16:14 | #12 |
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Most newer floppy drives are 5V only. I have Sony and Panasonic drives here that are 5V only, but also some older drives that require 12V. Check the PCB around the power connector and see if any traces go from the 12V pin, bearing in mind they could be on either side of the board.
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02 April 2020, 00:10 | #13 |
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If you use a dual fdd cable you can mod it so that either drive can be df0, but only one at once, I think from memory the switch switches between ds0 and ds1.
See here http://eab.abime.net/showthread.php?t=75886 Last edited by sneeker; 02 April 2020 at 00:12. Reason: Had a quick google to find the link. |
02 April 2020, 07:05 | #14 |
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I ended up shuffling the select line so that the external drive reads as DF0:, the drive daisy chained form that one reads as DF1: and so on. It wasn't too hard to do (and can be reversed) just by lifting some of the surface mount components near the external drive connector and using some 30 gauge kynar wire to connect to the right pads.
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02 April 2020, 15:05 | #15 |
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Thanks for all this info, folks. Unfortunately I lack the intellect to be able to understand the electronics side of it.
I carefully unscrewed the circuit board on the back of the old internal FDD to see if I could see any markings but there was nothing visible denoting voltages. I think I may have to just take a chance on that adapter and hope it will work with my old internal FDD but, as I said above, I appreciate the info. |
03 April 2020, 03:25 | #16 |
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If you look at this link: http://www.amigawiki.org/dnl/schematics/A1200_R1.pdf and study sheet 8 you can see how it is all connected. SEL0 connects to pin 10 on the internal header. if you connect that instead to pin 21 on the external connector then that makes the external floppy DF0:. If you take SEL1 that used to be connected to pin 21 there and instead connect it to pin 9 on that external connector then that will make a floppy that you daisy chain from DF0: into DF1:. A convenient place to make these changes is by removing some of the surface mount parts such as E580/E595 rather than getting into the connectors themselves.
It is completely understandable if you don't want to do this due to not having soldering/schematic experience but I thought it might be useful to put it here in the thread for future searchers. |
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