A Patch to FOCAL-W to Use the LINC-8 Display

This document describes a patch for the FOCAL-W (8/68) programming environment, designed to allow users of LINC-8 computers to utilize the LINC point display. The patch enables the user to set up and intensify X and Y coordinates similarly to the standard PDP-8 display, with specific adjustments:

• Coordinate Reversal: X and Y inputs are reversed (e.g., FDXS(X)+FDIS(Y) becomes FDXS(Y)+FDIS(X)).
• Coordinate Ranges: The X range is 0 to 512, and the Y range is -256 to +256 (decimal).
• Limitations: This patch overrides the existing ARCTAN FOCAL function. If ARCTAN is required, it must be calculated using the FEXP function instead.

The document provides the necessary assembly code and instructions to manually apply these changes to the FOCAL-W software.