PAK-II Datasheet, PDF (12/28 Pages) List of Unclassifed Manufacturers – 310 Ivy Glen Court

a pull up resistor, or just tie the Enable/Busy pin
directly to +5V.
If you ground the Busy/Mode input at start up, the
device will also use the Enable/Busy pin to tell
you when it is unavailable. It does this by driving
the line low when it is not ready. That means the
host must drive the pin with an open collector
output if it wants to disable the device. If you don't
need to disable the device, you can just connect the
pin to a pull up resistor and connect the Enable/
Busy pin to an input on the host.
If you want to use a normal output to drive the
Enable/Busy pin, but you still want a busy
indication, you can connect the Busy/Mode pin to
5V through a pull up resistor. Then the Pak II will
use the Busy/Mode pin to signify it is busy (the pin
is high when busy). In this case, the Enable/Busy
pin is always an input and you can drive it
normally.
Many commands have an alternate form. These
commands are the ones that return the floating
point error flags on completion. Using the alternate
form suppresses the status return value.
One thing to note about the status returns. All of
the commands that take any significant amount of
time will return zeros in the top bit of the response.
You can use this as a form of busy indication if
you are unwilling to use any other pins. Simply
read the data pin until it reads zero. This indicates