Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: curtis on December 13, 2017, 09:52:54 PM

Title: Sony MPF920 Z/131 as df1: in A2K
Post by: curtis on December 13, 2017, 09:52:54 PM
Finally got back to working on my A2000 with a new to me motherboard.

It's up and running with a new IDE4Z2 IDE interface with the nifty CF mounted right on the card which frees up a 3.5" bay for a second floppy drive internally.

However, the only floppy drives I have are the Sony's listed in the title. All work just fine as df0: but NOTHING works in the df1: position.  I know I need to adjust the drive settings from DS1, but for the life of me I can't find where on the circuit board to do so?

Any suggestions?  I'm including a picture of the circuit board on the drive so someone can tell me where to look.


Title: Re: Sony MPF920 Z/131 as df1: in A2K
Post by: BLTCON0 on December 14, 2017, 11:31:29 PM
Since this is a modded PC drive, it used to be set to DS1 (pin12) and someone configured it to DS0 (pin10) so it now works as df0: natively, just look for the mod and reverse it.

Or you can just re-wire the cable.

If you don't want to rewire the cable nor can you locate the DSx mod to reverse it, you can always short pins 10-12 on the floppy and cut off the prong for pin 10.
This way SEL1 signals (pin12) will be routed to pin10 (SEL0 - which the drive listens to), yet with the cut-off prong the drive will be deaf to SEL0 signals on the cable.
Title: Re: Sony MPF920 Z/131 as df1: in A2K
Post by: Amiwest on December 15, 2017, 03:20:02 AM
The A2000 with board part number 312723 has jumper J301 This jumper is closed to add a second internal floppy drive, open to leave the second floppy out of the main unit box. The X X Amiga expects an ID bit stream from each floppy drive; this lets it determine the drive type. External floppies have this ID circuitry on board, but as it's not an industry standard capability, it has to be implemented on the A2000 motherboard to save cost on internal drives. Leaving the jumper open prevents the Amiga from seeing the ID sequence.
A2000 with board part number 380705-01 - jumper J36.