README

PET/CBM EDIT ROM PROJECT - Steve J. Gray - Started Nov 26, 2013
======================== - Updated - Apr 26, 2022

This project will allow you to build various EDIT ROMS for the Commodore PET/CBM line of computers.

FILES:

make.bat	- Type "make" to assemble with options set in "edit.asm" file

edit.asm	- The "main" source file. Contains directives to choose which options to include/use.

editrom.asm	- Logic to assemble code in LOWER 2K area and determine if HI area is required.
edit_hi.asm	- Logic to assemble code in UPPER 2K area, including IO area.
editrom40.asm	- CODEBASE 0 - 40 column, 2K ROM
editrom80.asm   - CODEBASE 1 - 80 column, 2K ROM
editrom82.asm   - CODEBASE 2 - LOWER area. 80 column, 4K ROM, DIN editor
editrom82ext.asm- CODEBASE 2 - UPPER area.

ext*		- Code for CODEBASE 2's upper 2K of 4K (subsections)
crt*		- Files to define screen settings. Written to CRTC controller chip.
kbd*		- Files to define keyboard matrix for simple keyboard scanning routine.
kbdx*		- Keyboard matrices for extended keyboard scanning routine.
screen*		- Screen line pointer tables for 40/80 column screens
mem*		- Standard PET/CBM memory usage includes - zero page, low mem, and chips etc