Difference between revisions of "83Plus:BCALLs:408D"

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(Synopsis)
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'''BCALL Address:''' 408D
 
'''BCALL Address:''' 408D
  
Negates the floating point number in [[83Plus:RAM:8483|OP1]].
+
Negates the floating point number in [[83Plus:RAM:8478|OP1]].
  
 
=== Inputs ===
 
=== Inputs ===

Revision as of 21:32, 24 April 2005

Synopsis

Official Name: InvOP1S

BCALL Address: 408D

Negates the floating point number in OP1.

Inputs

  • OP1 = floating point number

Outputs

  • OP1 = -OP1

Registers Destroyed

  • AF

Comments

This routine inverts the sign bit of OP1 unless it is a floating point zero. If the value in OP1 is a floating point zero, then the sign bit is not inverted.

Example

B_CALL OP1Set3  ;OP1=floating point 3
B_CALL InvOP1S  ;returns with OP1=-3