Added the picture of the manual here

Please describe better what doesn't work:

• What type of computer are you using this drive in?
• What kind of disks are you trying to read/write?
• In case you use special software like IMD: What software do you use?
• How is the software configured (like: disk type in BIOS setup? configuration of IMD?)
• What kind of problems do you have (wrong rotational speed? computer can't read? computer can't format?)

im using a 486DX2 66mhz, trying to use imd118 and get this drive to go 300rpm instead of default 360rpm..

so trying to configure it so it can go 300rpm with the SR=300 switch to imd, but it cant read floppy when i have the dips changed to the 300rpm setting.
im using the test rpm option in imd to determine if its working or not.

For standard PC use, you need to keep the convention that pin 2 high means HD operation and pin 2 low means DD operation. So the dual-speed option that is at least partially PC compatible is the first(!) row of the manual, not the second one.

If you configure the drive to dual-speed operation and configure the drive as "1.2MB" in the BIOS, you should still be able to read/write HD disk, but you won't be able read DD disks, because the BIOS expects the drive to always spin at 360rpm and configures the floppy controller to 300kbps. In dual-speed mode, DD disks will be read at 250kbps. This can be handled by IMD, but not by the BIOS (or DOS using the BIOS). If you configure the drive as 360KB drive in the BIOS, it will handle 300rpm (250kbps) operation, but it will not double-step the drive, so the BIOS can only successfully read track 0. There is no way to configure the BIOS in a way that it can read 360KB disks in this drive in dual-speed mode.