Jumper settings

The 7287 DOES NOT CONTAIN JUMPER (W1)

PRIMARY/SECONDARY PORT ADDRESS JUMPERS (W2 & W3)

W2 and W3 jumpers are for the I/O port addresses.

W2 and W3 not installed = Primary port adress
                          1F0 to 1F7, 3F0 to 3F7        (Factory Default)
W2 and W3 installed = Secondary port adress
                          170 to 177, 370 to 377

INITIAL FLOPPY DATA RATE CONTROL JUMPER (W4)

Jumper W4 controls the power-up data transfer rate for the floppy drives.

W4 installed = 250KHz
W4 not installed = 500KHz               (Factory Default)

FIRMWARE/HARDWARE DRIVE SELECT MODE (W5)

Two modes of drive selection are supported in the hardware drive select mode,
the drive number is driven directly to the drive interface. In the firmware
drive select mode, the drive number is intercepted by the controller firmware.

W5 installed = Hardware Select Mode      (Factory Default)
W5 not installed = Firmware Select Mode

AUTO-DESELECT MODE (W6)

This jumper is used to control the drive select light (LED)
Removal of this jumper will cause the drive light (LED) to remain brightly
illuminated whenever power is on.

FLOPPY PRECOMPENSATION CONTROL JUMPER (W7)

Two modes of precompensation for the floppy drive are supported on the 7287

W7 installed = precompensation at 125ns
W7 not installed = precompensation is scaled by the data
                   rate of the floppy drive. (125ns for 500KHz, 208ns
                   for 300KHz, and 250ns for 250KHz). (Factory Default)

RESERVED JUMPER (W8)

Jumper W8 is for internal use only and must be installed (closed) for the
controller to operate.

BIOS PROM ADDRESS JUMPER (W9)

The 7287 requires 16K of memory. This block can be addressed beginning
at C800:0000 or D800:00000.

W9 installed = D8000:0000 to DC00:0000
W9 not installed = C800:0000 to CC00:0000 (Factory Default)

BIOS PROM ENABLE JUMPER (W10)

W10 installed = Enable the on-board BIOS PROM (Factory Default)
W10 not installed = Disable the on-board BIOS PROM

John, hope this all helps. Also the bios entry points for the low level
format routines are at C800:5 and D800:5 depending on the W9 jumper
setting. If you have anymore questions just let me know.






