The BBC and Master Computer Public Domain Library

A6A6 Floating-Point Multiply Entry Point

Submitted by Steve Fewell

Routine:amult
Name: Floating-Point Multiplication
Starting Address: &A6A6
Entry criteria: &4A and &4B (the argp) point to a 5-byte Floating-Point variable to multiply.
The FWA contains the other value to multiply [multiplicand].
Exit: The FWA = [argp] * FWA [Normalised and Rounded].

Description:

Call the Floating Point Multiplication routine [FWA = Argp Variable * FWB] to actually do the addition.
Jump to the 'Round FWA Mantissa to 4 bytes' routine at address &A695
so that we can exit with the resulted rounded and the Mantissa rounding byte clear.

Disassembly for the Floating-Point Multiply Entry Point routine