Mul-2reg

This document contains the program documentation for MUL-2REG, a subroutine designed for integer multiplication on systems where the hardware multiply function has restrictive capacity limits.

Key details include:

• Purpose: It allows users to multiply two registers (each containing values up to ±3777) and obtain a signed double-register product, bypassing the risk of silent overflow errors associated with the standard hardware 'MUL' command.
• Usage: Users integrate the manuscript into their program and call it via the JMP MUL2 instruction. Multiplicands are placed in specified locations (Z1 and Z2), and the routine returns the high-order bits of the product in A1 and low-order bits in A2.
• Specifications: The subroutine requires 61 (decimal) locations of memory, utilizes 11 index registers, and executes in less than 0.67 milliseconds.
• Content: The document includes the abstract, usage instructions, technical specifications, and the source code listing in LAP6.