DUAL DRIVE SUPPORT

The 8051A operates in a MASTER SLAVE relationship. This enables the 8051A to 

be daisy-chained with another IDE drive.(i.e. 7080A,7040A,or another 8051A)

1: Jumpering J4.1 to J4.2 causes the 8051A to operate in the SLAVE role.

2: Jumpering J4.5 to J4.6 causes the 8051A to operate in the MASTER role.
 

3: Jumpering J4.3 to J4.4 This allows the 8051A to be compatable with 
some BIOS versions that cannot support 1:1 interleave.This jumper should
not be installed under normal conditions.

4: Jumper J4.7 to J4.8 is not used and should not be installed.

5: Jumpering J4.9 to J4.10 enables the I/O ready signal onto the 
interface connector, pin 27.     


NOTE: The 8051A may be shipped with a jumper accross J4.1 and J4.3
this jumper has no effect but provides you with a spare.