Skip to navigation

Elite on the BBC Micro and NES

Maths (Arithmetic): MLU1

[BBC Micro cassette version]

Name: MLU1 [Show more] Type: Subroutine Category: Maths (Arithmetic) Summary: Calculate Y1 = y_hi and (A P) = |y_hi| * Q for Y-th stardust
Context: See this subroutine in context in the source code References: This subroutine is called as follows: * STARS1 calls MLU1 * STARS6 calls MLU1

Do the following assignment, and multiply the Y-th stardust particle's y-coordinate with an unsigned number Q: Y1 = y_hi (A P) = |y_hi| * Q
.MLU1 LDA SY,Y \ Set Y1 the Y-th byte of SY STA Y1 \ Fall through into MLU2 to calculate: \ \ (A P) = |A| * Q