I recently installed a Gotek floppy emulator in my A2000 (Rev 4. motherboard 1986 Germany 4 layers) and a bootselector.
I was worried because on some videos and guides (for example
https://www.youtube.com/watch?v=hTuWq6O6lVk) the Floppy drive is accessed whenever the Gotek is accessed, which causes needless wear on the 3.5" floppy drive and some noise.
This guide (
https://oldcrap.org/2018/08/30/amiga-2000/) does a big write up on the issue and how to solve it:
"
... becomes audible, that the second floppy motor is activated any time the other drive (Gotek) is accessed. This is because both floppies in Amiga share a single motor on signal (MTR0D). If this sound effect is annoying, we can eliminate it with a simple floppy mod.
Amiga has two signals on floppy connector to control each floppy: SELx and INUSEx. INUSEx becomes active before the data is transferred to/from floppy x and when it is active SELx controls the validity of the data on the bus. MTR0D seems to be actually = INUSE0 OR INUSE1 (logically). In order to enable the motor of drive 1 only when this drive is used, we need to remove the drive’s motor on signal from MTR0D and attach it to INUSE1. It can be done at the cable connection on the floppy board."
However, on my case, and perhaps by using the original cable within my A2000 I had no issue whatsoever - and therefore, because I found no guide on the internet for this early board revision, I'd like to leave the following information for anyone who might be doing the same:
So on the A2000 rev 4. the Braunshweig made, the 8520 CIA's are U10 and U11.
The EVEN one is U11.
You need to
close J36 (jumper 36) which lies a bit to the northeast of the two 8520 CIA chips to
enable Df0 and Df1.
On the connector cable side:
Middle of ribbon: Gotek - dip at S1 (mine came like that by default)
End of ribbon - internal Chinon FZ- 534 3.5" - dip change from one position to the other (my drive has 3 pins)
Now, since I installed a switchless boot selector, if I do Ctrl+Amiga+Amiga and hold for 5 seconds, it either boots from floppy, GOTEK or harddrive.
Of course, if no image or floppy are in, it defaults to the harddrive as it should.
I have no phantom drive access whatsoever when using the Gotek, so the issue is probably caused by the cable used.
