Submitted by Steve Fewell
Name: Store 1-byte value in FWA
Starting Address: &81D5
Entry criteria: A contains the 1-byte value to store in the FWA.
Exit: The FWA contains the 1-byte value.
Clear the FWA.
If the value to set the FWA to is positive then Set FWA to the value, Normalise and exit.
If the value to set the FWA to is negative, then Set the FWA Sign byte to Negative
and reverse the bits in the number and add 1 to make the value positive.
Now it is ok to set the FWA to the value, Normalise the FWA and exit.
We set Y to &88 when the Normalise routine is called, to tell the routine that
our FWA value is 8-bits in size, so set the Initial exponent to &80 + 8 (=&88),
so that the '.' is located after the first 8 bits.
|81D5||032 180 166||20 B4 A6||JSR &A6B4 Clear FWA|
|81D9||016 005||10 05||BPL 5 --> &81E0 Normalise FWA#2|
|81DB||.||133 046||85 2E||STA &2E|
|81DD||I||073 255||49 FF||EOR#&FF|
|81E0||160 136||A0 88||LDY#&88|